From c5a759c044a51988d9f5d32209b6048cfee4f333 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Romain=20Semp=C3=A9?= <romain@getlago.com>
Date: Wed, 24 Aug 2022 12:07:40 +0200
Subject: [PATCH 1/9] misc: Rename unique_id to external_id

---
 .../api/v1/subscriptions_controller.rb        |  2 +-
 app/models/subscription.rb                    | 10 ++---
 app/serializers/v1/event_serializer.rb        |  2 +-
 app/serializers/v1/subscription_serializer.rb |  2 +-
 app/services/subscriptions/create_service.rb  | 16 +++----
 ...ique_id_to_external_id_on_subscriptions.rb |  5 +++
 db/schema.rb                                  |  2 +-
 db/seeds.rb                                   |  2 +-
 spec/factories/subscription_factory.rb        |  2 +-
 spec/models/subscription_spec.rb              | 20 ++++-----
 spec/requests/api/v1/subscriptions_spec.rb    |  2 +-
 .../subscriptions/create_service_spec.rb      | 42 +++++++++----------
 12 files changed, 56 insertions(+), 51 deletions(-)
 create mode 100644 db/migrate/20220823145421_rename_unique_id_to_external_id_on_subscriptions.rb

diff --git a/app/controllers/api/v1/subscriptions_controller.rb b/app/controllers/api/v1/subscriptions_controller.rb
index a0610df62ca..300e24d0c7e 100644
--- a/app/controllers/api/v1/subscriptions_controller.rb
+++ b/app/controllers/api/v1/subscriptions_controller.rb
@@ -86,7 +86,7 @@ def index
 
       def create_params
         params.require(:subscription)
-          .permit(:customer_id, :plan_code, :name, :subscription_id, :unique_id, :billing_time)
+          .permit(:customer_id, :plan_code, :name, :subscription_id, :external_id, :billing_time)
       end
 
       def update_params
diff --git a/app/models/subscription.rb b/app/models/subscription.rb
index b01884cde91..286b4454c9d 100644
--- a/app/models/subscription.rb
+++ b/app/models/subscription.rb
@@ -12,8 +12,8 @@ class Subscription < ApplicationRecord
   has_many :invoices, through: :invoice_subscriptions
   has_many :fees
 
-  validates :unique_id, presence: true
-  validate :validate_unique_id, on: :create
+  validates :external_id, presence: true
+  validate :validate_external_id, on: :create
 
   STATUSES = [
     :pending,
@@ -71,10 +71,10 @@ def already_billed?
     fees.subscription_kind.any?
   end
 
-  def validate_unique_id
+  def validate_external_id
     return unless active?
 
-    used_ids = customer&.active_subscriptions&.pluck(:unique_id)
-    errors.add(:unique_id, :value_already_exists) if used_ids&.include?(unique_id)
+    used_ids = customer&.active_subscriptions&.pluck(:external_id)
+    errors.add(:external_id, :value_already_exists) if used_ids&.include?(external_id)
   end
 end
diff --git a/app/serializers/v1/event_serializer.rb b/app/serializers/v1/event_serializer.rb
index 10121192c20..a365177643f 100644
--- a/app/serializers/v1/event_serializer.rb
+++ b/app/serializers/v1/event_serializer.rb
@@ -12,7 +12,7 @@ def serialize
         timestamp: model.timestamp.iso8601,
         properties: model.properties,
         lago_subscription_id: model.subscription_id,
-        subscription_unique_id: model.subscription&.unique_id,
+        external_subscription_id: model.subscription&.external_id,
         created_at: model.created_at.iso8601
       }
     end
diff --git a/app/serializers/v1/subscription_serializer.rb b/app/serializers/v1/subscription_serializer.rb
index 8edc9b9f34d..289e3e5898b 100644
--- a/app/serializers/v1/subscription_serializer.rb
+++ b/app/serializers/v1/subscription_serializer.rb
@@ -5,10 +5,10 @@ class SubscriptionSerializer < ModelSerializer
     def serialize
       {
         lago_id: model.id,
+        external_id: model.external_id,
         lago_customer_id: model.customer_id,
         customer_id: model.customer.customer_id,
         name: model.name,
-        unique_id: model.unique_id,
         plan_code: model.plan.code,
         status: model.status,
         billing_time: model.billing_time,
diff --git a/app/services/subscriptions/create_service.rb b/app/services/subscriptions/create_service.rb
index 69fc1d66cdf..308cc1e57d4 100644
--- a/app/services/subscriptions/create_service.rb
+++ b/app/services/subscriptions/create_service.rb
@@ -2,7 +2,7 @@
 
 module Subscriptions
   class CreateService < BaseService
-    attr_reader :current_customer, :current_plan, :current_subscription, :name, :unique_id, :billing_time
+    attr_reader :current_customer, :current_plan, :current_subscription, :name, :external_id, :billing_time
 
     def create_from_api(organization:, params:)
       if params[:customer_id]
@@ -18,7 +18,7 @@ def create_from_api(organization:, params:)
         code: params[:plan_code]&.strip,
       )
       @name = params[:name]&.strip
-      @unique_id = params[:unique_id]&.strip
+      @external_id = params[:external_id]&.strip
       @billing_time = params[:billing_time]
       @current_subscription = find_current_subscription(subscription_id: params[:subscription_id])
 
@@ -40,7 +40,7 @@ def create(**args)
 
       # NOTE: prepare subscription attributes
       @name = args[:name]&.strip
-      @unique_id = SecureRandom.uuid
+      @external_id = SecureRandom.uuid
       @billing_time = args[:billing_time]
       @current_subscription = find_current_subscription(subscription_id: args[:subscription_id])
 
@@ -97,7 +97,7 @@ def create_subscription
         plan_id: current_plan.id,
         subscription_date: Time.zone.now.to_date,
         name: name,
-        unique_id: unique_id || current_customer.customer_id,
+        external_id: external_id || current_customer.customer_id,
         billing_time: billing_time || :calendar,
       )
       new_subscription.mark_as_active!
@@ -117,7 +117,7 @@ def upgrade_subscription
         customer: current_customer,
         plan: current_plan,
         name: name,
-        unique_id: current_subscription.unique_id,
+        external_id: current_subscription.external_id,
         previous_subscription_id: current_subscription.id,
         subscription_date: current_subscription.subscription_date,
         billing_time: current_subscription.billing_time,
@@ -159,7 +159,7 @@ def downgrade_subscription
           customer: current_customer,
           plan: current_plan,
           name: name,
-          unique_id: current_subscription.unique_id,
+          external_id: current_subscription.external_id,
           previous_subscription_id: current_subscription.id,
           subscription_date: current_subscription.subscription_date,
           status: :pending,
@@ -215,9 +215,9 @@ def active_subscriptions
 
     def find_current_subscription(subscription_id:)
       return active_subscriptions&.find_by(id: subscription_id) if subscription_id
-      return active_subscriptions&.find_by(unique_id: unique_id) if unique_id
+      return active_subscriptions&.find_by(external_id: external_id) if external_id
 
-      active_subscriptions&.find_by(unique_id: current_customer.customer_id)
+      active_subscriptions&.find_by(external_id: current_customer.customer_id)
     end
   end
 end
diff --git a/db/migrate/20220823145421_rename_unique_id_to_external_id_on_subscriptions.rb b/db/migrate/20220823145421_rename_unique_id_to_external_id_on_subscriptions.rb
new file mode 100644
index 00000000000..b8117802d9c
--- /dev/null
+++ b/db/migrate/20220823145421_rename_unique_id_to_external_id_on_subscriptions.rb
@@ -0,0 +1,5 @@
+class RenameUniqueIdToExternalIdOnSubscriptions < ActiveRecord::Migration[7.0]
+  def change
+    rename_column :subscriptions, :unique_id, :external_id
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 5c6593012fa..f6f61020c20 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -346,7 +346,7 @@
     t.uuid "previous_subscription_id"
     t.date "subscription_date"
     t.string "name"
-    t.string "unique_id", null: false
+    t.string "external_id", null: false
     t.integer "billing_time", default: 0, null: false
     t.index ["customer_id"], name: "index_subscriptions_on_customer_id"
     t.index ["plan_id"], name: "index_subscriptions_on_plan_id"
diff --git a/db/seeds.rb b/db/seeds.rb
index 6b4270f53cf..252e5e325a3 100644
--- a/db/seeds.rb
+++ b/db/seeds.rb
@@ -66,7 +66,7 @@
     status: :active,
   ).find_or_create_by!(
     customer: customer,
-    unique_id: SecureRandom.uuid,
+    external_id: SecureRandom.uuid,
     plan: plan,
   )
 
diff --git a/spec/factories/subscription_factory.rb b/spec/factories/subscription_factory.rb
index 4316614ee3a..fcf5937dd86 100644
--- a/spec/factories/subscription_factory.rb
+++ b/spec/factories/subscription_factory.rb
@@ -5,7 +5,7 @@
     customer
     plan
     status { :active }
-    unique_id { SecureRandom.uuid }
+    external_id { SecureRandom.uuid }
 
     factory :active_subscription do
       status { :active }
diff --git a/spec/models/subscription_spec.rb b/spec/models/subscription_spec.rb
index 715919ecca8..a05b8e60c67 100644
--- a/spec/models/subscription_spec.rb
+++ b/spec/models/subscription_spec.rb
@@ -3,7 +3,7 @@
 require 'rails_helper'
 
 RSpec.describe Subscription, type: :model do
-  describe '.upgraded?' do
+  describe '#upgraded?' do
     let(:previous_subscription) { nil }
     let(:plan) { create(:plan) }
 
@@ -48,7 +48,7 @@
     end
   end
 
-  describe '.downgraded?' do
+  describe '#downgraded?' do
     let(:previous_subscription) { nil }
     let(:plan) { create(:plan, amount_cents: 100) }
 
@@ -93,7 +93,7 @@
     end
   end
 
-  describe '.trial_end_date' do
+  describe '#trial_end_date' do
     let(:plan) { create(:plan, trial_period: 3) }
     let(:subscription) { create(:active_subscription, plan: plan) }
 
@@ -115,24 +115,24 @@
     end
   end
 
-  describe '.valid_unique_id' do
+  describe '#valid_external_id' do
     let(:organization) { create(:organization) }
     let(:customer) { create(:customer, organization: organization) }
     let(:plan) { create(:plan) }
-    let(:unique_id) { SecureRandom.uuid }
+    let(:external_id) { SecureRandom.uuid }
     let(:subscription) { create(:active_subscription, plan: plan, customer: customer) }
-    let(:new_subscription) { build(:active_subscription, plan: plan, unique_id: unique_id, customer: customer) }
+    let(:new_subscription) { build(:active_subscription, plan: plan, external_id: external_id, customer: customer) }
 
     before { subscription }
 
-    context 'when unique_id is unique' do
-      it 'does not raise validation error if unique_id is unique' do
+    context 'when external_id is unique' do
+      it 'does not raise validation error if external_id is unique' do
         expect(new_subscription).to be_valid
       end
     end
 
-    context 'when unique_id is NOT unique' do
-      let(:unique_id) { subscription.unique_id }
+    context 'when external_id is NOT unique' do
+      let(:external_id) { subscription.external_id }
 
       it 'raises validation error' do
         expect(new_subscription).not_to be_valid
diff --git a/spec/requests/api/v1/subscriptions_spec.rb b/spec/requests/api/v1/subscriptions_spec.rb
index ccff28e2c95..951276b9fa4 100644
--- a/spec/requests/api/v1/subscriptions_spec.rb
+++ b/spec/requests/api/v1/subscriptions_spec.rb
@@ -13,7 +13,7 @@
         customer_id: customer.customer_id,
         plan_code: plan.code,
         name: 'subscription name',
-        unique_id: SecureRandom.uuid,
+        external_id: SecureRandom.uuid,
         billing_time: 'anniversary',
       }
     end
diff --git a/spec/services/subscriptions/create_service_spec.rb b/spec/services/subscriptions/create_service_spec.rb
index e84443783ef..56383806bf4 100644
--- a/spec/services/subscriptions/create_service_spec.rb
+++ b/spec/services/subscriptions/create_service_spec.rb
@@ -10,14 +10,14 @@
   describe '.create_from_api' do
     let(:plan) { create(:plan, amount_cents: 100, organization: organization) }
     let(:customer) { create(:customer, organization: organization) }
-    let(:unique_id) { SecureRandom.uuid }
+    let(:external_id) { SecureRandom.uuid }
 
     let(:params) do
       {
         customer_id: customer.customer_id,
         plan_code: plan.code,
         name: 'invoice display name',
-        unique_id: unique_id,
+        external_id: external_id,
         billing_time: 'anniversary',
       }
     end
@@ -43,21 +43,21 @@
         expect(subscription.subscription_date).to be_present
         expect(subscription.name).to eq('invoice display name')
         expect(subscription).to be_active
-        expect(subscription.unique_id).to be_present
+        expect(subscription.external_id).to be_present
         expect(subscription).to be_anniversary
       end
     end
 
-    context 'when unique_id is not given' do
-      let(:unique_id) { nil }
+    context 'when external_id is not given' do
+      let(:external_id) { nil }
 
-      it 'sets customer_id as unique_id' do
+      it 'sets customer_id as external_id' do
         result = create_service.create_from_api(
           organization: organization,
           params: params,
         )
 
-        expect(result.subscription.unique_id).to eq(customer.customer_id)
+        expect(result.subscription.external_id).to eq(customer.customer_id)
       end
     end
 
@@ -67,7 +67,7 @@
           customer_id: customer.customer_id,
           plan_code: plan.code,
           name: 'invoice display name',
-          unique_id: unique_id,
+          external_id: external_id,
         }
       end
 
@@ -111,7 +111,7 @@
         {
           customer_id: SecureRandom.uuid,
           plan_code: plan.code,
-          unique_id: unique_id,
+          external_id: external_id,
         }
       end
 
@@ -153,7 +153,7 @@
         {
           customer_id: nil,
           plan_code: plan.code,
-          unique_id: unique_id,
+          external_id: external_id,
         }
       end
 
@@ -173,7 +173,7 @@
         {
           customer_id: customer.customer_id,
           plan_code: 'invalid_plan',
-          unique_id: unique_id,
+          external_id: external_id,
         }
       end
 
@@ -193,7 +193,7 @@
         {
           customer_id: customer.id,
           plan_code: plan.code,
-          unique_id: unique_id,
+          external_id: external_id,
           billing_time: :foo,
         }
       end
@@ -220,7 +220,7 @@
           plan_code: plan.code,
           name: 'invoice display name',
           subscription_id: subscription.id,
-          unique_id: unique_id,
+          external_id: external_id,
         }
       end
       let(:subscription) do
@@ -248,18 +248,18 @@
         end
       end
 
-      context 'when unique_id is given but not subscription_id' do
+      context 'when external_id is given but not subscription_id' do
         let(:params) do
           {
             customer_id: customer.customer_id,
             plan_code: plan.code,
             name: 'invoice display name',
-            unique_id: unique_id,
+            external_id: external_id,
           }
         end
 
         it 'returns existing subscription' do
-          subscription.update!(unique_id: unique_id)
+          subscription.update!(external_id: external_id)
 
           result = create_service.create_from_api(
             organization: organization,
@@ -271,7 +271,7 @@
         end
       end
 
-      context 'when subscription_id and unique_id are not given' do
+      context 'when subscription_id and external_id are not given' do
         let(:params) do
           {
             customer_id: customer.customer_id,
@@ -281,7 +281,7 @@
         end
 
         it 'returns existing subscription' do
-          subscription.update!(unique_id: customer.customer_id)
+          subscription.update!(external_id: customer.customer_id)
 
           result = create_service.create_from_api(
             organization: organization,
@@ -300,7 +300,7 @@
             customer_id: customer.customer_id,
             plan_code: new_plan.code,
             name: 'invoice display name new',
-            unique_id: unique_id,
+            external_id: external_id,
           }
         end
 
@@ -324,7 +324,7 @@
               plan_code: higher_plan.code,
               name: 'invoice display name new',
               subscription_id: subscription.id,
-              unique_id: unique_id,
+              external_id: external_id,
             }
           end
 
@@ -419,7 +419,7 @@
               plan_code: lower_plan.code,
               name: 'invoice display name new',
               subscription_id: subscription.id,
-              unique_id: unique_id,
+              external_id: external_id,
             }
           end
 

From b49adbd727239e8de4ad943439be39dc35f90627 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Romain=20Semp=C3=A9?= <romain@getlago.com>
Date: Fri, 26 Aug 2022 17:39:50 +0200
Subject: [PATCH 2/9] misc: Refactor to use external_id on customers and
 subscriptions

---
 .../api/v1/applied_add_ons_controller.rb      |   2 +-
 .../api/v1/applied_coupons_controller.rb      |   2 +-
 .../api/v1/customers_controller.rb            |   6 +-
 app/controllers/api/v1/events_controller.rb   |   8 +-
 .../api/v1/subscriptions_controller.rb        |   8 +-
 app/graphql/mutations/customers/create.rb     |   2 +-
 app/graphql/mutations/customers/update.rb     |   2 +-
 app/graphql/types/customers/object.rb         |   2 +-
 app/graphql/types/events/object.rb            |  10 +-
 app/models/customer.rb                        |   2 +-
 .../v1/applied_add_on_serializer.rb           |   2 +-
 .../v1/applied_coupon_serializer.rb           |   2 +-
 app/serializers/v1/customer_serializer.rb     |   2 +-
 app/serializers/v1/event_serializer.rb        |   3 +-
 .../customer_error_serializer.rb              |   2 +-
 .../invoice_payment_error_serializer.rb       |   2 +-
 app/serializers/v1/subscription_serializer.rb |   2 +-
 .../applied_add_ons/create_service.rb         |   2 +-
 .../applied_coupons/create_service.rb         |   2 +-
 app/services/customers/create_service.rb      |   4 +-
 app/services/customers/update_service.rb      |   6 +-
 app/services/events/create_batch_service.rb   |  11 +-
 app/services/events/create_service.rb         |  20 ++--
 .../events/validate_creation_service.rb       |  20 ++--
 .../invoices/customer_usage_service.rb        |  15 +--
 .../create_service.rb                         |   2 +-
 .../stripe_service.rb                         |   2 +-
 app/services/subscriptions/create_service.rb  |  13 ++-
 .../subscriptions/terminate_service.rb        |   4 +-
 app/services/subscriptions/update_service.rb  |   4 +-
 config/routes.rb                              |   6 +-
 ...customer_id_to_external_id_on_customers.rb |   5 +
 db/schema.rb                                  |   4 +-
 db/seeds.rb                                   |   2 +-
 schema.graphql                                |  10 +-
 schema.json                                   |  54 +++++-----
 spec/factories/customer_factory.rb            |   2 +-
 .../mutations/customers/create_spec.rb        |  10 +-
 .../mutations/customers/update_spec.rb        |  10 +-
 .../customers/update_vat_rate_spec.rb         |   2 +-
 .../resolvers/customer_resolver_spec.rb       |   2 +-
 .../resolvers/customers_resolver_spec.rb      |   2 +-
 .../graphql/resolvers/events_resolver_spec.rb |   4 +-
 spec/models/customer_spec.rb                  |   4 +-
 spec/requests/api/v1/applied_add_ons_spec.rb  |   4 +-
 spec/requests/api/v1/applied_coupons_spec.rb  |   4 +-
 spec/requests/api/v1/customers_spec.rb        |  12 +--
 spec/requests/api/v1/events_spec.rb           |  10 +-
 spec/requests/api/v1/subscriptions_spec.rb    |  14 +--
 .../customer_error_serializer_spec.rb         |   2 +-
 .../invoice_payment_error_serializer_spec.rb  |   2 +-
 .../applied_add_ons/create_service_spec.rb    |   6 +-
 .../applied_coupons/create_service_spec.rb    |   6 +-
 .../services/customers/create_service_spec.rb |  22 ++--
 .../services/customers/update_service_spec.rb |  14 +--
 .../events/create_batch_service_spec.rb       |   8 +-
 spec/services/events/create_service_spec.rb   |  33 +++---
 .../events/validate_creation_service_spec.rb  |  42 ++++----
 .../subscriptions/create_service_spec.rb      | 100 ++++++++----------
 .../subscriptions/terminate_service_spec.rb   |   9 +-
 .../subscriptions/update_service_spec.rb      |   6 +-
 spec/services/webhooks/event_service_spec.rb  |   2 +-
 62 files changed, 282 insertions(+), 295 deletions(-)
 create mode 100644 db/migrate/20220824113131_rename_customer_id_to_external_id_on_customers.rb

diff --git a/app/controllers/api/v1/applied_add_ons_controller.rb b/app/controllers/api/v1/applied_add_ons_controller.rb
index 044015a1fb1..82e90547111 100644
--- a/app/controllers/api/v1/applied_add_ons_controller.rb
+++ b/app/controllers/api/v1/applied_add_ons_controller.rb
@@ -26,7 +26,7 @@ def create
 
       def create_params
         params.require(:applied_add_on).permit(
-          :customer_id,
+          :external_customer_id,
           :add_on_code,
           :amount_cents,
           :amount_currency,
diff --git a/app/controllers/api/v1/applied_coupons_controller.rb b/app/controllers/api/v1/applied_coupons_controller.rb
index 774d63977c9..1fa2d66c2ec 100644
--- a/app/controllers/api/v1/applied_coupons_controller.rb
+++ b/app/controllers/api/v1/applied_coupons_controller.rb
@@ -26,7 +26,7 @@ def create
 
       def create_params
         params.require(:applied_coupon).permit(
-          :customer_id,
+          :external_customer_id,
           :coupon_code,
           :amount_cents,
           :amount_currency,
diff --git a/app/controllers/api/v1/customers_controller.rb b/app/controllers/api/v1/customers_controller.rb
index 0ecf4c2fa85..b9c5c3d88d2 100644
--- a/app/controllers/api/v1/customers_controller.rb
+++ b/app/controllers/api/v1/customers_controller.rb
@@ -26,8 +26,8 @@ def current_usage
         service = Invoices::CustomerUsageService
           .new(
             nil,
-            customer_id: params[:customer_id],
-            subscription_id: params[:subscription_id],
+            customer_id: params[:customer_external_id],
+            subscription_id: params[:external_subscription_id],
             organization_id: current_organization.id,
           )
         result = service.usage
@@ -49,7 +49,7 @@ def current_usage
 
       def create_params
         params.require(:customer).permit(
-          :customer_id,
+          :external_id,
           :name,
           :country,
           :address_line1,
diff --git a/app/controllers/api/v1/events_controller.rb b/app/controllers/api/v1/events_controller.rb
index 45adda8e17f..b19ae73cf86 100644
--- a/app/controllers/api/v1/events_controller.rb
+++ b/app/controllers/api/v1/events_controller.rb
@@ -54,10 +54,10 @@ def create_params
           .require(:event)
           .permit(
             :transaction_id,
-            :customer_id,
+            :external_customer_id,
             :code,
             :timestamp,
-            :subscription_id,
+            :external_subscription_id,
             properties: {},
           )
       end
@@ -67,10 +67,10 @@ def batch_params
           .require(:event)
           .permit(
             :transaction_id,
-            :customer_id,
+            :external_customer_id,
             :code,
             :timestamp,
-            subscription_ids: [],
+            external_subscription_ids: [],
             properties: {},
           )
       end
diff --git a/app/controllers/api/v1/subscriptions_controller.rb b/app/controllers/api/v1/subscriptions_controller.rb
index 300e24d0c7e..2425ec3491e 100644
--- a/app/controllers/api/v1/subscriptions_controller.rb
+++ b/app/controllers/api/v1/subscriptions_controller.rb
@@ -27,7 +27,7 @@ def terminate
         result = Subscriptions::TerminateService.new
           .terminate_from_api(
             organization: current_organization,
-            subscription_id: params[:id]
+            external_id: params[:external_id]
           )
 
         if result.success?
@@ -47,7 +47,7 @@ def update
 
         result = service.update_from_api(
           organization: current_organization,
-          id: params[:id],
+          external_id: params[:external_id],
           params: update_params
         )
 
@@ -64,7 +64,7 @@ def update
       end
 
       def index
-        customer = current_organization.customers.find_by(customer_id: params[:customer_id])
+        customer = current_organization.customers.find_by(external_id: params[:external_customer_id])
 
         return not_found_error unless customer
 
@@ -86,7 +86,7 @@ def index
 
       def create_params
         params.require(:subscription)
-          .permit(:customer_id, :plan_code, :name, :subscription_id, :external_id, :billing_time)
+          .permit(:external_customer_id, :plan_code, :name, :subscription_id, :external_id, :billing_time)
       end
 
       def update_params
diff --git a/app/graphql/mutations/customers/create.rb b/app/graphql/mutations/customers/create.rb
index 51a66e03fed..3a3434ec6ab 100644
--- a/app/graphql/mutations/customers/create.rb
+++ b/app/graphql/mutations/customers/create.rb
@@ -10,7 +10,7 @@ class Create < BaseMutation
       description 'Creates a new customer'
 
       argument :name, String, required: true
-      argument :customer_id, String, required: true
+      argument :external_id, String, required: true
       argument :country, Types::CountryCodeEnum, required: false
       argument :address_line1, String, required: false
       argument :address_line2, String, required: false
diff --git a/app/graphql/mutations/customers/update.rb b/app/graphql/mutations/customers/update.rb
index b2d911c3986..feec4fecdfe 100644
--- a/app/graphql/mutations/customers/update.rb
+++ b/app/graphql/mutations/customers/update.rb
@@ -10,7 +10,7 @@ class Update < BaseMutation
 
       argument :id, ID, required: true
       argument :name, String, required: true
-      argument :customer_id, String, required: true
+      argument :external_id, String, required: true
       argument :country, Types::CountryCodeEnum, required: false
       argument :address_line1, String, required: false
       argument :address_line2, String, required: false
diff --git a/app/graphql/types/customers/object.rb b/app/graphql/types/customers/object.rb
index 3c3f0ef0c7a..ddc35b06699 100644
--- a/app/graphql/types/customers/object.rb
+++ b/app/graphql/types/customers/object.rb
@@ -7,7 +7,7 @@ class Object < Types::BaseObject
 
       field :id, ID, null: false
 
-      field :customer_id, String, null: false
+      field :external_id, String, null: false
       field :name, String
       field :sequential_id, String, null: false
       field :slug, String, null: false
diff --git a/app/graphql/types/events/object.rb b/app/graphql/types/events/object.rb
index 27e646c115d..b2dc152515e 100644
--- a/app/graphql/types/events/object.rb
+++ b/app/graphql/types/events/object.rb
@@ -1,5 +1,3 @@
-# r
-
 module Types
   module Events
     class Object < Types::BaseObject
@@ -8,7 +6,7 @@ class Object < Types::BaseObject
       field :id, ID, null: false
       field :code, String, null: false
 
-      field :customer_id, String, null: false
+      field :external_customer_id, String, null: false
       field :subscription_id, String, null: false
       field :transaction_id, String, null: true
 
@@ -27,15 +25,15 @@ def received_at
         object.created_at
       end
 
-      def customer_id
-        object.customer.customer_id
+      def external_customer_id
+        object.customer.external_id
       end
 
       def payload
         {
           event: {
             transaction_id: object.transaction_id,
-            customer_id: object.customer.customer_id,
+            external_customer_id: object.customer.external_id,
             subscription_id: object.subscription_id,
             code: object.code,
             timestamp: object.timestamp.to_i,
diff --git a/app/models/customer.rb b/app/models/customer.rb
index 1a95ebab036..4123e0500be 100644
--- a/app/models/customer.rb
+++ b/app/models/customer.rb
@@ -27,7 +27,7 @@ class Customer < ApplicationRecord
 
   sequenced scope: ->(customer) { customer.organization.customers }
 
-  validates :customer_id, presence: true, uniqueness: { scope: :organization_id }
+  validates :external_id, presence: true, uniqueness: { scope: :organization_id }
   validates :country, country_code: true, unless: -> { country.nil? }
   validates :vat_rate, numericality: { less_than_or_equal_to: 100, greater_than_or_equal_to: 0 }, allow_nil: true
   validates :payment_provider, inclusion: { in: PAYMENT_PROVIDERS }, allow_nil: true
diff --git a/app/serializers/v1/applied_add_on_serializer.rb b/app/serializers/v1/applied_add_on_serializer.rb
index 12aabdfb2e2..fe5e5c00dfd 100644
--- a/app/serializers/v1/applied_add_on_serializer.rb
+++ b/app/serializers/v1/applied_add_on_serializer.rb
@@ -7,8 +7,8 @@ def serialize
         lago_id: model.id,
         lago_add_on_id: model.add_on.id,
         add_on_code: model.add_on.code,
-        customer_id: model.customer.customer_id,
         lago_customer_id: model.customer.id,
+        external_customer_id: model.customer.external_id,
         amount_cents: model.amount_cents,
         amount_currency: model.amount_currency,
         created_at: model.created_at.iso8601,
diff --git a/app/serializers/v1/applied_coupon_serializer.rb b/app/serializers/v1/applied_coupon_serializer.rb
index 06d8bf7b3b3..0ecd0e56daf 100644
--- a/app/serializers/v1/applied_coupon_serializer.rb
+++ b/app/serializers/v1/applied_coupon_serializer.rb
@@ -7,8 +7,8 @@ def serialize
         lago_id: model.id,
         lago_coupon_id: model.coupon.id,
         coupon_code: model.coupon.code,
-        customer_id: model.customer.customer_id,
         lago_customer_id: model.customer.id,
+        external_customer_id: model.customer.external_id,
         amount_cents: model.amount_cents,
         amount_currency: model.amount_currency,
         expiration_date: model.coupon.expiration_date&.iso8601,
diff --git a/app/serializers/v1/customer_serializer.rb b/app/serializers/v1/customer_serializer.rb
index ca69164216e..390de160997 100644
--- a/app/serializers/v1/customer_serializer.rb
+++ b/app/serializers/v1/customer_serializer.rb
@@ -5,7 +5,7 @@ class CustomerSerializer < ModelSerializer
     def serialize
       {
         lago_id: model.id,
-        customer_id: model.customer_id,
+        external_id: model.external_id,
         name: model.name,
         sequential_id: model.sequential_id,
         slug: model.slug,
diff --git a/app/serializers/v1/event_serializer.rb b/app/serializers/v1/event_serializer.rb
index a365177643f..e855746e509 100644
--- a/app/serializers/v1/event_serializer.rb
+++ b/app/serializers/v1/event_serializer.rb
@@ -1,5 +1,4 @@
 # frozen_string_literal: true
-#
 module V1
   class EventSerializer < ModelSerializer
     def serialize
@@ -7,7 +6,7 @@ def serialize
         lago_id: model.id,
         transaction_id: model.transaction_id,
         lago_customer_id: model.customer_id,
-        customer_id: model.customer&.customer_id,
+        external_customer_id: model.customer&.external_id,
         code: model.code,
         timestamp: model.timestamp.iso8601,
         properties: model.properties,
diff --git a/app/serializers/v1/payment_providers/customer_error_serializer.rb b/app/serializers/v1/payment_providers/customer_error_serializer.rb
index b5760d71a1e..14e1b3b01c9 100644
--- a/app/serializers/v1/payment_providers/customer_error_serializer.rb
+++ b/app/serializers/v1/payment_providers/customer_error_serializer.rb
@@ -6,7 +6,7 @@ class CustomerErrorSerializer < ModelSerializer
       def serialize
         {
           lago_customer_id: model.id,
-          customer_id: model.customer_id,
+          external_customer_id: model.external_id,
           payment_provider: model.payment_provider,
           provider_error: options[:provider_error],
         }
diff --git a/app/serializers/v1/payment_providers/invoice_payment_error_serializer.rb b/app/serializers/v1/payment_providers/invoice_payment_error_serializer.rb
index ef27ed39d0d..997ba60adb7 100644
--- a/app/serializers/v1/payment_providers/invoice_payment_error_serializer.rb
+++ b/app/serializers/v1/payment_providers/invoice_payment_error_serializer.rb
@@ -9,7 +9,7 @@ def serialize
         {
           lago_invoice_id: invoice.id,
           lago_customer_id: invoice.customer.id,
-          customer_id: invoice.customer.customer_id,
+          external_customer_id: invoice.customer.external_id,
           provider_customer_id: options[:provider_customer_id],
           payment_provider: invoice.customer.payment_provider,
           provider_error: options[:provider_error],
diff --git a/app/serializers/v1/subscription_serializer.rb b/app/serializers/v1/subscription_serializer.rb
index 289e3e5898b..36069b68a07 100644
--- a/app/serializers/v1/subscription_serializer.rb
+++ b/app/serializers/v1/subscription_serializer.rb
@@ -7,7 +7,7 @@ def serialize
         lago_id: model.id,
         external_id: model.external_id,
         lago_customer_id: model.customer_id,
-        customer_id: model.customer.customer_id,
+        external_customer_id: model.customer.external_id,
         name: model.name,
         plan_code: model.plan.code,
         status: model.status,
diff --git a/app/services/applied_add_ons/create_service.rb b/app/services/applied_add_ons/create_service.rb
index 5fe5e0cd27b..d46440155dc 100644
--- a/app/services/applied_add_ons/create_service.rb
+++ b/app/services/applied_add_ons/create_service.rb
@@ -21,7 +21,7 @@ def create(**args)
 
     def create_from_api(organization:, args:)
       @customer = Customer.find_by(
-        customer_id: args[:customer_id],
+        external_id: args[:external_customer_id],
         organization_id: organization.id,
       )
 
diff --git a/app/services/applied_coupons/create_service.rb b/app/services/applied_coupons/create_service.rb
index 8b2cbb8bb5d..4574000d4cc 100644
--- a/app/services/applied_coupons/create_service.rb
+++ b/app/services/applied_coupons/create_service.rb
@@ -21,7 +21,7 @@ def create(**args)
 
     def create_from_api(organization:, args:)
       @customer = Customer.find_by(
-        customer_id: args[:customer_id],
+        external_id: args[:external_customer_id],
         organization_id: organization.id,
       )
 
diff --git a/app/services/customers/create_service.rb b/app/services/customers/create_service.rb
index 52969b1bb7e..d4e238c5031 100644
--- a/app/services/customers/create_service.rb
+++ b/app/services/customers/create_service.rb
@@ -3,7 +3,7 @@
 module Customers
   class CreateService < BaseService
     def create_from_api(organization:, params:)
-      customer = organization.customers.find_or_initialize_by(customer_id: params[:customer_id])
+      customer = organization.customers.find_or_initialize_by(external_id: params[:external_id])
 
       customer.name = params[:name] if params.key?(:name)
       customer.country = params[:country]&.upcase if params.key?(:country)
@@ -35,7 +35,7 @@ def create_from_api(organization:, params:)
     def create(**args)
       customer = Customer.create!(
         organization_id: args[:organization_id],
-        customer_id: args[:customer_id],
+        external_id: args[:external_id],
         name: args[:name],
         country: args[:country]&.upcase,
         address_line1: args[:address_line1],
diff --git a/app/services/customers/update_service.rb b/app/services/customers/update_service.rb
index 8697def8498..fd68fbbf518 100644
--- a/app/services/customers/update_service.rb
+++ b/app/services/customers/update_service.rb
@@ -22,9 +22,9 @@ def update(**args)
       customer.vat_rate = args[:vat_rate] if args.key?(:vat_rate)
       customer.payment_provider = args[:payment_provider] if args.key?(:payment_provider)
 
-      # NOTE: Customer_id is not editable if customer is attached to subscriptions
-      if !customer.attached_to_subscriptions? && args.key?(:customer_id)
-        customer.customer_id = args[:customer_id]
+      # NOTE: external_id is not editable if customer is attached to subscriptions
+      if !customer.attached_to_subscriptions? && args.key?(:external_id)
+        customer.external_id = args[:external_id]
       end
 
       customer.save!
diff --git a/app/services/events/create_batch_service.rb b/app/services/events/create_batch_service.rb
index 3437a122cfd..973466dadac 100644
--- a/app/services/events/create_batch_service.rb
+++ b/app/services/events/create_batch_service.rb
@@ -2,7 +2,7 @@
 
 module Events
   class CreateBatchService < BaseService
-    ALL_REQUIRED_PARAMS = %i[transaction_id code subscription_ids].freeze
+    ALL_REQUIRED_PARAMS = %i[transaction_id code external_subscription_ids].freeze
 
     def validate_params(params:)
       missing_params = ALL_REQUIRED_PARAMS.select { |key| params[key].blank? }
@@ -13,7 +13,7 @@ def validate_params(params:)
 
     def call(organization:, params:, timestamp:, metadata:)
       customer = organization.subscriptions.find_by(
-        id: params[:subscription_ids]&.first
+        external_id: params[:external_subscription_ids]&.first
       )&.customer
 
       Events::ValidateCreationService.call(
@@ -27,8 +27,9 @@ def call(organization:, params:, timestamp:, metadata:)
 
       events = []
       ActiveRecord::Base.transaction do
-        params[:subscription_ids].each do |id|
-          event = organization.events.find_by(transaction_id: params[:transaction_id], subscription_id: id)
+        params[:external_subscription_ids].each do |id|
+          subscription = Subscription.find_by(external_id: id)
+          event = organization.events.find_by(transaction_id: params[:transaction_id], subscription_id: subscription.id)
 
           if event
             events << event
@@ -40,7 +41,7 @@ def call(organization:, params:, timestamp:, metadata:)
           event.code = params[:code]
           event.transaction_id = params[:transaction_id]
           event.customer = customer
-          event.subscription_id = id
+          event.subscription_id = subscription.id
           event.properties = params[:properties] || {}
           event.metadata = metadata || {}
 
diff --git a/app/services/events/create_service.rb b/app/services/events/create_service.rb
index c9e2f7c752a..d63c9a0febf 100644
--- a/app/services/events/create_service.rb
+++ b/app/services/events/create_service.rb
@@ -3,17 +3,17 @@
 module Events
   class CreateService < BaseService
     ALL_REQUIRED_PARAMS = %i[transaction_id code].freeze
-    ONE_REQUIRED_PARAMS = %i[subscription_id customer_id].freeze
+    ONE_REQUIRED_PARAMS = %i[external_subscription_id external_customer_id].freeze
 
     def validate_params(params:)
       missing_params = ALL_REQUIRED_PARAMS.select { |key| params[key].blank? }
       missing_params |= ONE_REQUIRED_PARAMS if ONE_REQUIRED_PARAMS.all? { |key| params[key].blank? }
 
       # NOTE: In case of multiple subscriptions, we return an error if subscription_id is not given.
-      if params[:customer_id].present? && params[:subscription_id].blank?
-        customer = Customer.find_by(customer_id: params[:customer_id])
+      if params[:external_customer_id].present? && params[:external_subscription_id].blank?
+        customer = Customer.find_by(external_id: params[:external_customer_id])
         subscriptions_count = customer ? customer.active_subscriptions.count : 0
-        missing_params |= %i[subscription_id] if subscriptions_count > 1
+        missing_params |= %i[external_subscription_id] if subscriptions_count > 1
       end
 
       return result if missing_params.blank?
@@ -22,10 +22,10 @@ def validate_params(params:)
     end
 
     def call(organization:, params:, timestamp:, metadata:)
-      customer = if params[:subscription_id]
-        organization.subscriptions.find_by(id: params[:subscription_id])&.customer
+      customer = if params[:external_subscription_id]
+        organization.subscriptions.find_by(external_id: params[:external_subscription_id])&.customer
       else
-        Customer.find_by(customer_id: params[:customer_id], organization_id: organization.id)
+        Customer.find_by(external_id: params[:external_customer_id], organization_id: organization.id)
       end
 
       Events::ValidateCreationService.call(
@@ -37,8 +37,8 @@ def call(organization:, params:, timestamp:, metadata:)
 
       return result unless result.success?
 
-      subscription_id = params[:subscription_id] || customer&.active_subscriptions&.pluck(:id).first
-      event = organization.events.find_by(transaction_id: params[:transaction_id], subscription_id: subscription_id)
+      subscription = Subscription.find_by(external_id: params[:external_subscription_id]) || customer&.active_subscriptions&.first
+      event = organization.events.find_by(transaction_id: params[:transaction_id], subscription_id: subscription.id)
 
       if event
         result.event = event
@@ -49,7 +49,7 @@ def call(organization:, params:, timestamp:, metadata:)
       event.code = params[:code]
       event.transaction_id = params[:transaction_id]
       event.customer = customer
-      event.subscription_id = subscription_id
+      event.subscription_id = subscription.id
       event.properties = params[:properties] || {}
       event.metadata = metadata || {}
 
diff --git a/app/services/events/validate_creation_service.rb b/app/services/events/validate_creation_service.rb
index 78ba3e1249e..3af9ce1c01c 100644
--- a/app/services/events/validate_creation_service.rb
+++ b/app/services/events/validate_creation_service.rb
@@ -23,10 +23,10 @@ def call
     attr_reader :organization, :params, :result, :customer, :batch
 
     def validate_create_batch
-      return blank_subscription_error if params[:subscription_ids].blank?
+      return blank_subscription_error if params[:external_subscription_ids].blank?
       return invalid_customer_error unless customer
 
-      invalid_subscriptions = params[:subscription_ids].select { |arg| !customer_subscription_ids.include?(arg) }
+      invalid_subscriptions = params[:external_subscription_ids].select { |arg| !customer_external_subscription_ids.include?(arg) }
       return invalid_subscription_error if invalid_subscriptions.present?
       return invalid_code_error unless valid_code?
     end
@@ -34,20 +34,20 @@ def validate_create_batch
     def validate_create
       return invalid_customer_error unless customer
 
-      if customer_subscription_ids.count > 1
-        return blank_subscription_error if params[:subscription_id].blank?
+      if customer_external_subscription_ids.count > 1
+        return blank_subscription_error if params[:external_subscription_id].blank?
         return invalid_subscription_error unless valid_subscription_id?
-      elsif params[:subscription_id]
+      elsif params[:external_subscription_id]
         return invalid_subscription_error unless valid_subscription_id?
       else
-        return blank_subscription_error if customer_subscription_ids.blank?
+        return blank_subscription_error if customer_external_subscription_ids.blank?
       end
 
       return invalid_code_error unless valid_code?
     end
 
     def valid_subscription_id?
-      customer_subscription_ids.include?(params[:subscription_id])
+      customer_external_subscription_ids.include?(params[:external_subscription_id])
     end
 
     def valid_code?
@@ -66,8 +66,8 @@ def send_webhook_notice
       SendWebhookJob.perform_later(:event, object)
     end
 
-    def customer_subscription_ids
-      @customer_subscription_ids ||= customer&.active_subscriptions&.pluck(:id)
+    def customer_external_subscription_ids
+      @customer_external_subscription_ids ||= customer&.active_subscriptions&.pluck(:external_id)
     end
 
     def blank_subscription_error
@@ -76,7 +76,7 @@ def blank_subscription_error
     end
 
     def invalid_subscription_error
-      result.fail!(code: 'invalid_argument', message: 'subscription_id is invalid')
+      result.fail!(code: 'invalid_argument', message: 'external_subscription_id is invalid')
       send_webhook_notice
     end
 
diff --git a/app/services/invoices/customer_usage_service.rb b/app/services/invoices/customer_usage_service.rb
index d65a00cfb8f..60713ae2c4f 100644
--- a/app/services/invoices/customer_usage_service.rb
+++ b/app/services/invoices/customer_usage_service.rb
@@ -2,20 +2,19 @@
 
 module Invoices
   class CustomerUsageService < BaseService
+    # NOTE: customer_id can reference the lago id or the external id of the customer
+    # NOTE: subscription_id can reference the lago id or the external id of the subscription
     def initialize(current_user, customer_id:, subscription_id:, organization_id: nil)
       super(current_user)
 
       if organization_id.present?
         @organization_id = organization_id
-        @customer = Customer.find_by!(
-          customer_id: customer_id,
-          organization_id: organization_id,
-        )
+        @customer = Customer.find_by!(external_id: customer_id, organization_id: organization_id)
+        @subscription = @customer&.active_subscriptions&.find_by(external_id: subscription_id)
       else
         customer(customer_id: customer_id)
+        @subscription = @customer&.active_subscriptions&.find_by(id: subscription_id)
       end
-
-      @subscription = find_subscription(subscription_id)
     rescue ActiveRecord::RecordNotFound
       result.fail!(code: 'not_found')
     end
@@ -60,10 +59,6 @@ def customer(customer_id: nil)
       )
     end
 
-    def find_subscription(subscription_id)
-      customer&.active_subscriptions&.find_by(id: subscription_id)
-    end
-
     def add_charge_fee
       query = subscription.plan.charges.joins(:billable_metric)
         .order(Arel.sql('lower(unaccent(billable_metrics.name)) ASC'))
diff --git a/app/services/payment_provider_customers/create_service.rb b/app/services/payment_provider_customers/create_service.rb
index 7f6ae441a11..2b9a5a799c9 100644
--- a/app/services/payment_provider_customers/create_service.rb
+++ b/app/services/payment_provider_customers/create_service.rb
@@ -10,7 +10,7 @@ def initialize(customer)
 
     def create_or_update(customer_class:, payment_provider_id:, params:, async: true)
       provider_customer = customer_class.find_or_initialize_by(
-        customer_id: customer.id,
+        customer_id: customer.id, # TODO: Why?
         payment_provider_id: payment_provider_id,
       )
 
diff --git a/app/services/payment_provider_customers/stripe_service.rb b/app/services/payment_provider_customers/stripe_service.rb
index 6e0f1d6561d..96bab5d5bdf 100644
--- a/app/services/payment_provider_customers/stripe_service.rb
+++ b/app/services/payment_provider_customers/stripe_service.rb
@@ -113,7 +113,7 @@ def stripe_create_payload
         name: customer.name,
         metadata: {
           lago_customer_id: customer.id,
-          customer_id: customer.customer_id,
+          customer_id: customer.external_id,
         },
         phone: customer.phone,
       }
diff --git a/app/services/subscriptions/create_service.rb b/app/services/subscriptions/create_service.rb
index 308cc1e57d4..debbe5be66a 100644
--- a/app/services/subscriptions/create_service.rb
+++ b/app/services/subscriptions/create_service.rb
@@ -5,9 +5,9 @@ class CreateService < BaseService
     attr_reader :current_customer, :current_plan, :current_subscription, :name, :external_id, :billing_time
 
     def create_from_api(organization:, params:)
-      if params[:customer_id]
+      if params[:external_customer_id]
         @current_customer = Customer.find_or_create_by!(
-          customer_id: params[:customer_id]&.strip,
+          external_id: params[:external_customer_id]&.strip,
           organization_id: organization.id,
         )
       end
@@ -20,7 +20,7 @@ def create_from_api(organization:, params:)
       @name = params[:name]&.strip
       @external_id = params[:external_id]&.strip
       @billing_time = params[:billing_time]
-      @current_subscription = find_current_subscription(subscription_id: params[:subscription_id])
+      @current_subscription = find_current_subscription
 
       process_create
     rescue ActiveRecord::RecordInvalid => e
@@ -43,7 +43,6 @@ def create(**args)
       @external_id = SecureRandom.uuid
       @billing_time = args[:billing_time]
       @current_subscription = find_current_subscription(subscription_id: args[:subscription_id])
-
       process_create
     end
 
@@ -97,7 +96,7 @@ def create_subscription
         plan_id: current_plan.id,
         subscription_date: Time.zone.now.to_date,
         name: name,
-        external_id: external_id || current_customer.customer_id,
+        external_id: external_id || current_customer.external_id,
         billing_time: billing_time || :calendar,
       )
       new_subscription.mark_as_active!
@@ -213,11 +212,11 @@ def active_subscriptions
       @active_subscriptions ||= current_customer&.active_subscriptions
     end
 
-    def find_current_subscription(subscription_id:)
+    def find_current_subscription(subscription_id: nil)
       return active_subscriptions&.find_by(id: subscription_id) if subscription_id
       return active_subscriptions&.find_by(external_id: external_id) if external_id
 
-      active_subscriptions&.find_by(external_id: current_customer.customer_id)
+      active_subscriptions&.find_by(external_id: current_customer.external_id)
     end
   end
 end
diff --git a/app/services/subscriptions/terminate_service.rb b/app/services/subscriptions/terminate_service.rb
index 7b13154f0af..046148eaaed 100644
--- a/app/services/subscriptions/terminate_service.rb
+++ b/app/services/subscriptions/terminate_service.rb
@@ -9,8 +9,8 @@ def terminate(subscription_id)
       process_terminate(subscription)
     end
 
-    def terminate_from_api(organization:, subscription_id:)
-      subscription = organization.subscriptions.find_by(id: subscription_id)
+    def terminate_from_api(organization:, external_id:)
+      subscription = organization.subscriptions.find_by(external_id: external_id)
       return result.fail!(code: 'not_found', message: 'subscription is not found') if subscription.blank?
 
       process_terminate(subscription)
diff --git a/app/services/subscriptions/update_service.rb b/app/services/subscriptions/update_service.rb
index 97c0922cfae..5e8c1aeb2fc 100644
--- a/app/services/subscriptions/update_service.rb
+++ b/app/services/subscriptions/update_service.rb
@@ -16,8 +16,8 @@ def update(**args)
       result.fail_with_validations!(e.record)
     end
 
-    def update_from_api(organization:, id:, params:)
-      subscription = organization.subscriptions.find_by(id: id)
+    def update_from_api(organization:, external_id:, params:)
+      subscription = organization.subscriptions.find_by(external_id: external_id)
       return result.fail!(code: 'not_found', message: 'subscription is not found') unless subscription
 
       subscription.name = params[:name] if params.key?(:name)
diff --git a/config/routes.rb b/config/routes.rb
index 70f091f3e35..575d2e00a8d 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -16,12 +16,12 @@
 
   namespace :api do
     namespace :v1 do
-      resources :customers, only: %i[create] do
+      resources :customers, param: :external_id, only: %i[create] do
         get :current_usage
       end
 
-      resources :subscriptions, only: %i[create update index]
-      delete '/subscriptions/:id', to: 'subscriptions#terminate', as: :terminate
+      resources :subscriptions, only: %i[create update index], param: :external_id
+      delete '/subscriptions/:external_id', to: 'subscriptions#terminate', as: :terminate
 
       resources :add_ons, param: :code
       resources :billable_metrics, param: :code
diff --git a/db/migrate/20220824113131_rename_customer_id_to_external_id_on_customers.rb b/db/migrate/20220824113131_rename_customer_id_to_external_id_on_customers.rb
new file mode 100644
index 00000000000..e68ea4040c4
--- /dev/null
+++ b/db/migrate/20220824113131_rename_customer_id_to_external_id_on_customers.rb
@@ -0,0 +1,5 @@
+class RenameCustomerIdToExternalIdOnCustomers < ActiveRecord::Migration[7.0]
+  def change
+    rename_column :customers, :customer_id, :external_id
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index f6f61020c20..ee7d0680210 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -136,7 +136,7 @@
   end
 
   create_table "customers", id: :uuid, default: -> { "gen_random_uuid()" }, force: :cascade do |t|
-    t.string "customer_id", null: false
+    t.string "external_id", null: false
     t.string "name"
     t.uuid "organization_id", null: false
     t.datetime "created_at", null: false
@@ -157,7 +157,7 @@
     t.string "payment_provider"
     t.string "slug"
     t.bigint "sequential_id"
-    t.index ["customer_id"], name: "index_customers_on_customer_id"
+    t.index ["external_id"], name: "index_customers_on_external_id"
     t.index ["organization_id"], name: "index_customers_on_organization_id"
   end
 
diff --git a/db/seeds.rb b/db/seeds.rb
index 252e5e325a3..2435d08b67a 100644
--- a/db/seeds.rb
+++ b/db/seeds.rb
@@ -58,7 +58,7 @@
     legal_number: Faker::Company.duns_number,
   ).find_or_create_by!(
     organization: organization,
-    customer_id: "cust_#{i + 1}",
+    external_id: "cust_#{i + 1}",
   )
 
   sub = Subscription.create_with(
diff --git a/schema.graphql b/schema.graphql
index dbe4406c8bc..307241e227d 100644
--- a/schema.graphql
+++ b/schema.graphql
@@ -1594,8 +1594,8 @@ input CreateCustomerInput {
   """
   clientMutationId: String
   country: CountryCode
-  customerId: String!
   email: String
+  externalId: String!
   legalName: String
   legalNumber: String
   logoUrl: String
@@ -2377,8 +2377,8 @@ type Customer {
   city: String
   country: CountryCode
   createdAt: ISO8601DateTime!
-  customerId: String!
   email: String
+  externalId: String!
 
   """
   Define if a customer has an active wallet
@@ -2425,8 +2425,8 @@ type CustomerDetails {
   country: CountryCode
   createdAt: ISO8601DateTime!
   currency: CurrencyEnum
-  customerId: String!
   email: String
+  externalId: String!
 
   """
   Define if a customer has an active wallet
@@ -2620,7 +2620,7 @@ type Event {
   apiClient: String
   billableMetricName: String
   code: String!
-  customerId: String!
+  externalCustomerId: String!
   id: ID!
   ipAddress: String
   matchBillableMetric: Boolean!
@@ -3516,8 +3516,8 @@ input UpdateCustomerInput {
   """
   clientMutationId: String
   country: CountryCode
-  customerId: String!
   email: String
+  externalId: String!
   id: ID!
   legalName: String
   legalNumber: String
diff --git a/schema.json b/schema.json
index 3aeeca7449e..59700629dfb 100644
--- a/schema.json
+++ b/schema.json
@@ -4519,7 +4519,7 @@
               "deprecationReason": null
             },
             {
-              "name": "customerId",
+              "name": "externalId",
               "description": null,
               "type": {
                 "kind": "NON_NULL",
@@ -6169,16 +6169,12 @@
               ]
             },
             {
-              "name": "customerId",
+              "name": "email",
               "description": null,
               "type": {
-                "kind": "NON_NULL",
-                "name": null,
-                "ofType": {
-                  "kind": "SCALAR",
-                  "name": "String",
-                  "ofType": null
-                }
+                "kind": "SCALAR",
+                "name": "String",
+                "ofType": null
               },
               "isDeprecated": false,
               "deprecationReason": null,
@@ -6187,12 +6183,16 @@
               ]
             },
             {
-              "name": "email",
+              "name": "externalId",
               "description": null,
               "type": {
-                "kind": "SCALAR",
-                "name": "String",
-                "ofType": null
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "SCALAR",
+                  "name": "String",
+                  "ofType": null
+                }
               },
               "isDeprecated": false,
               "deprecationReason": null,
@@ -6705,16 +6705,12 @@
               ]
             },
             {
-              "name": "customerId",
+              "name": "email",
               "description": null,
               "type": {
-                "kind": "NON_NULL",
-                "name": null,
-                "ofType": {
-                  "kind": "SCALAR",
-                  "name": "String",
-                  "ofType": null
-                }
+                "kind": "SCALAR",
+                "name": "String",
+                "ofType": null
               },
               "isDeprecated": false,
               "deprecationReason": null,
@@ -6723,12 +6719,16 @@
               ]
             },
             {
-              "name": "email",
+              "name": "externalId",
               "description": null,
               "type": {
-                "kind": "SCALAR",
-                "name": "String",
-                "ofType": null
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "SCALAR",
+                  "name": "String",
+                  "ofType": null
+                }
               },
               "isDeprecated": false,
               "deprecationReason": null,
@@ -7827,7 +7827,7 @@
               ]
             },
             {
-              "name": "customerId",
+              "name": "externalCustomerId",
               "description": null,
               "type": {
                 "kind": "NON_NULL",
@@ -12829,7 +12829,7 @@
               "deprecationReason": null
             },
             {
-              "name": "customerId",
+              "name": "externalId",
               "description": null,
               "type": {
                 "kind": "NON_NULL",
diff --git a/spec/factories/customer_factory.rb b/spec/factories/customer_factory.rb
index 940ec9108e0..b4ff189d06c 100644
--- a/spec/factories/customer_factory.rb
+++ b/spec/factories/customer_factory.rb
@@ -4,7 +4,7 @@
   factory :customer do
     organization
     name { Faker::TvShows::SiliconValley.character }
-    customer_id { SecureRandom.uuid }
+    external_id { SecureRandom.uuid }
     country { Faker::Address.country_code }
     address_line1 { Faker::Address.street_address }
     address_line2 { Faker::Address.secondary_address }
diff --git a/spec/graphql/mutations/customers/create_spec.rb b/spec/graphql/mutations/customers/create_spec.rb
index cbe0cc080b8..b7caccc7620 100644
--- a/spec/graphql/mutations/customers/create_spec.rb
+++ b/spec/graphql/mutations/customers/create_spec.rb
@@ -13,7 +13,7 @@
         createCustomer(input: $input) {
           id,
           name,
-          customerId,
+          externalId,
           city
           country
           paymentProvider
@@ -33,7 +33,7 @@
       variables: {
         input: {
           name: 'John Doe',
-          customerId: 'john_doe_2',
+          externalId: 'john_doe_2',
           city: 'London',
           country: 'GB',
           paymentProvider: 'stripe',
@@ -49,7 +49,7 @@
     aggregate_failures do
       expect(result_data['id']).to be_present
       expect(result_data['name']).to eq('John Doe')
-      expect(result_data['customerId']).to eq('john_doe_2')
+      expect(result_data['externalId']).to eq('john_doe_2')
       expect(result_data['city']).to eq('London')
       expect(result_data['country']).to eq('GB')
       expect(result_data['paymentProvider']).to eq('stripe')
@@ -66,7 +66,7 @@
         variables: {
           input: {
             name: 'John Doe',
-            customerId: 'john_doe_2',
+            externalId: 'john_doe_2',
           },
         },
       )
@@ -83,7 +83,7 @@
         variables: {
           input: {
             name: 'John Doe',
-            customerId: 'john_doe_2',
+            externalId: 'john_doe_2',
           },
         },
       )
diff --git a/spec/graphql/mutations/customers/update_spec.rb b/spec/graphql/mutations/customers/update_spec.rb
index 65edf7dda66..44771d8ccea 100644
--- a/spec/graphql/mutations/customers/update_spec.rb
+++ b/spec/graphql/mutations/customers/update_spec.rb
@@ -14,7 +14,7 @@
         updateCustomer(input: $input) {
           id,
           name,
-          customerId
+          externalId
           paymentProvider
           stripeCustomer { id, providerCustomerId }
         }
@@ -24,7 +24,7 @@
 
   it 'updates a customer' do
     stripe_provider
-    customer_id = SecureRandom.uuid
+    external_id = SecureRandom.uuid
 
     result = execute_graphql(
       current_user: membership.user,
@@ -33,7 +33,7 @@
         input: {
           id: customer.id,
           name: 'Updated customer',
-          customerId: customer_id,
+          externalId: external_id,
           paymentProvider: 'stripe',
           stripeCustomer: {
             providerCustomerId: 'cu_12345',
@@ -47,7 +47,7 @@
     aggregate_failures do
       expect(result_data['id']).to be_present
       expect(result_data['name']).to eq('Updated customer')
-      expect(result_data['customerId']).to eq(customer_id)
+      expect(result_data['externalId']).to eq(external_id)
       expect(result_data['paymentProvider']).to eq('stripe')
       expect(result_data['stripeCustomer']['id']).to be_present
       expect(result_data['stripeCustomer']['providerCustomerId']).to eq('cu_12345')
@@ -62,7 +62,7 @@
           input: {
             id: customer.id,
             name: 'Updated customer',
-            customerId: SecureRandom.uuid,
+            externalId: SecureRandom.uuid,
           },
         },
       )
diff --git a/spec/graphql/mutations/customers/update_vat_rate_spec.rb b/spec/graphql/mutations/customers/update_vat_rate_spec.rb
index 7b1a528d755..572f30ecdf0 100644
--- a/spec/graphql/mutations/customers/update_vat_rate_spec.rb
+++ b/spec/graphql/mutations/customers/update_vat_rate_spec.rb
@@ -13,7 +13,7 @@
         updateCustomerVatRate(input: $input) {
           id,
           name,
-          customerId,
+          externalId,
           vatRate
         }
       }
diff --git a/spec/graphql/resolvers/customer_resolver_spec.rb b/spec/graphql/resolvers/customer_resolver_spec.rb
index 5b63bb4575c..74f028d0fad 100644
--- a/spec/graphql/resolvers/customer_resolver_spec.rb
+++ b/spec/graphql/resolvers/customer_resolver_spec.rb
@@ -7,7 +7,7 @@
     <<~GQL
       query($customerId: ID!) {
         customer(id: $customerId) {
-          id customerId name currency
+          id externalId name currency
           invoices { id invoiceType status }
           subscriptions(status: [active]) { id, status }
           appliedCoupons { id amountCents amountCurrency coupon { id name } }
diff --git a/spec/graphql/resolvers/customers_resolver_spec.rb b/spec/graphql/resolvers/customers_resolver_spec.rb
index cb35a01456d..753b43128b9 100644
--- a/spec/graphql/resolvers/customers_resolver_spec.rb
+++ b/spec/graphql/resolvers/customers_resolver_spec.rb
@@ -7,7 +7,7 @@
     <<~GQL
       query {
         customers(limit: 5) {
-          collection { id customerId name }
+          collection { id externalId name }
           metadata { currentPage, totalCount }
         }
       }
diff --git a/spec/graphql/resolvers/events_resolver_spec.rb b/spec/graphql/resolvers/events_resolver_spec.rb
index 54e62248185..d3931fb49ba 100644
--- a/spec/graphql/resolvers/events_resolver_spec.rb
+++ b/spec/graphql/resolvers/events_resolver_spec.rb
@@ -10,7 +10,7 @@
           collection {
             id,
             code,
-            customerId,
+            externalCustomerId,
             transactionId,
             timestamp,
             receivedAt,
@@ -58,7 +58,7 @@
       expect(events_response['collection'].count).to eq(organization.events.count)
       expect(events_response['collection'].first['id']).to eq(event.id)
       expect(events_response['collection'].first['code']).to eq(event.code)
-      expect(events_response['collection'].first['customerId']).to eq(event.customer.customer_id)
+      expect(events_response['collection'].first['externalCustomerId']).to eq(event.customer.external_id)
       expect(events_response['collection'].first['transactionId']).to eq(event.transaction_id)
       expect(events_response['collection'].first['timestamp']).to eq(event.timestamp.iso8601)
       expect(events_response['collection'].first['receivedAt']).to eq(event.created_at.iso8601)
diff --git a/spec/models/customer_spec.rb b/spec/models/customer_spec.rb
index 370f8dcd585..f47eb002c51 100644
--- a/spec/models/customer_spec.rb
+++ b/spec/models/customer_spec.rb
@@ -9,11 +9,11 @@
     subject(:customer) do
       described_class.new(
         organization: organization,
-        customer_id: customer_id,
+        external_id: external_id,
       )
     end
 
-    let(:customer_id) { SecureRandom.uuid }
+    let(:external_id) { SecureRandom.uuid }
 
     it 'validates the country' do
       expect(customer).to be_valid
diff --git a/spec/requests/api/v1/applied_add_ons_spec.rb b/spec/requests/api/v1/applied_add_ons_spec.rb
index 5cc494024c4..d497522a0e8 100644
--- a/spec/requests/api/v1/applied_add_ons_spec.rb
+++ b/spec/requests/api/v1/applied_add_ons_spec.rb
@@ -14,7 +14,7 @@
 
     let(:params) do
       {
-        customer_id: customer.customer_id,
+        external_customer_id: customer.external_id,
         add_on_code: add_on.code,
       }
     end
@@ -33,8 +33,8 @@
       aggregate_failures do
         expect(result[:lago_id]).to be_present
         expect(result[:lago_add_on_id]).to eq(add_on.id)
-        expect(result[:customer_id]).to eq(customer.customer_id)
         expect(result[:lago_customer_id]).to eq(customer.id)
+        expect(result[:external_customer_id]).to eq(customer.external_id)
         expect(result[:amount_cents]).to eq(add_on.amount_cents)
         expect(result[:amount_currency]).to eq(add_on.amount_currency)
         expect(result[:created_at]).to be_present
diff --git a/spec/requests/api/v1/applied_coupons_spec.rb b/spec/requests/api/v1/applied_coupons_spec.rb
index 54824b76433..810a390232f 100644
--- a/spec/requests/api/v1/applied_coupons_spec.rb
+++ b/spec/requests/api/v1/applied_coupons_spec.rb
@@ -14,7 +14,7 @@
 
     let(:params) do
       {
-        customer_id: customer.customer_id,
+        external_customer_id: customer.external_id,
         coupon_code: coupon.code,
       }
     end
@@ -33,8 +33,8 @@
       aggregate_failures do
         expect(result[:lago_id]).to be_present
         expect(result[:lago_coupon_id]).to eq(coupon.id)
-        expect(result[:customer_id]).to eq(customer.customer_id)
         expect(result[:lago_customer_id]).to eq(customer.id)
+        expect(result[:external_customer_id]).to eq(customer.external_id)
         expect(result[:amount_cents]).to eq(coupon.amount_cents)
         expect(result[:amount_currency]).to eq(coupon.amount_currency)
         expect(result[:expiration_date]).to be_nil
diff --git a/spec/requests/api/v1/customers_spec.rb b/spec/requests/api/v1/customers_spec.rb
index 2a43ef4edd7..c915a6a3423 100644
--- a/spec/requests/api/v1/customers_spec.rb
+++ b/spec/requests/api/v1/customers_spec.rb
@@ -7,7 +7,7 @@
     let(:organization) { create(:organization) }
     let(:create_params) do
       {
-        customer_id: SecureRandom.uuid,
+        external_id: SecureRandom.uuid,
         name: 'Foo Bar'
       }
     end
@@ -19,7 +19,7 @@
 
       result = JSON.parse(response.body, symbolize_names: true)[:customer]
       expect(result[:lago_id]).to be_present
-      expect(result[:customer_id]).to eq(create_params[:customer_id])
+      expect(result[:external_id]).to eq(create_params[:external_id])
       expect(result[:name]).to eq(create_params[:name])
       expect(result[:created_at]).to be_present
     end
@@ -27,7 +27,7 @@
     context 'with billing configuration' do
       let(:create_params) do
         {
-          customer_id: SecureRandom.uuid,
+          external_id: SecureRandom.uuid,
           name: 'Foo Bar',
           billing_configuration: {
             payment_provider: 'stripe',
@@ -43,7 +43,7 @@
 
         result = JSON.parse(response.body, symbolize_names: true)[:customer]
         expect(result[:lago_id]).to be_present
-        expect(result[:customer_id]).to eq(create_params[:customer_id])
+        expect(result[:external_id]).to eq(create_params[:external_id])
 
         expect(result[:billing_configuration]).to be_present
         expect(result[:billing_configuration][:payment_provider]).to eq('stripe')
@@ -114,7 +114,7 @@
 
     it 'returns the usage for the customer' do
       get_with_token(organization,
-        "/api/v1/customers/#{customer.customer_id}/current_usage?subscription_id=#{subscription.id}"
+        "/api/v1/customers/#{customer.external_id}/current_usage?external_subscription_id=#{subscription.external_id}"
       )
 
       aggregate_failures do
@@ -148,7 +148,7 @@
       it 'returns not found' do
         get_with_token(
           organization,
-          "/api/v1/customers/#{customer.customer_id}/current_usage?subscription_id=#{subscription.id}",
+          "/api/v1/customers/#{customer.external_id}/current_usage?external_subscription_id=#{subscription.external_id}",
         )
 
         expect(response).to have_http_status(:not_found)
diff --git a/spec/requests/api/v1/events_spec.rb b/spec/requests/api/v1/events_spec.rb
index b133a517d4d..0402c74386f 100644
--- a/spec/requests/api/v1/events_spec.rb
+++ b/spec/requests/api/v1/events_spec.rb
@@ -13,7 +13,7 @@
         event: {
           code: 'event_code',
           transaction_id: SecureRandom.uuid,
-          customer_id: SecureRandom.uuid,
+          external_customer_id: SecureRandom.uuid,
           timestamp: Time.zone.now.to_i,
           properties: {
             foo: 'bar',
@@ -30,7 +30,7 @@
         post_with_token(
           organization,
           '/api/v1/events',
-          event: { customer_id: SecureRandom.uuid },
+          event: { external_customer_id: SecureRandom.uuid },
         )
 
         expect(response).to have_http_status(:unprocessable_entity)
@@ -48,8 +48,8 @@
         event: {
           code: 'event_code',
           transaction_id: SecureRandom.uuid,
-          customer_id: SecureRandom.uuid,
-          subscription_ids: %w[id1 id2],
+          external_customer_id: SecureRandom.uuid,
+          external_subscription_ids: %w[id1 id2],
           timestamp: Time.zone.now.to_i,
           properties: {
             foo: 'bar',
@@ -69,7 +69,7 @@
           event: {
             code: 'event_code',
             transaction_id: SecureRandom.uuid,
-            customer_id: SecureRandom.uuid,
+            external_customer_id: SecureRandom.uuid,
             timestamp: Time.zone.now.to_i,
             properties: {
               foo: 'bar',
diff --git a/spec/requests/api/v1/subscriptions_spec.rb b/spec/requests/api/v1/subscriptions_spec.rb
index 951276b9fa4..fbf292458c2 100644
--- a/spec/requests/api/v1/subscriptions_spec.rb
+++ b/spec/requests/api/v1/subscriptions_spec.rb
@@ -10,7 +10,7 @@
   describe 'create' do
     let(:params) do
       {
-        customer_id: customer.customer_id,
+        external_customer_id: customer.external_id,
         plan_code: plan.code,
         name: 'subscription name',
         external_id: SecureRandom.uuid,
@@ -26,7 +26,7 @@
       result = JSON.parse(response.body, symbolize_names: true)[:subscription]
 
       expect(result[:lago_id]).to be_present
-      expect(result[:customer_id]).to eq(customer.customer_id)
+      expect(result[:external_customer_id]).to eq(customer.external_id)
       expect(result[:lago_customer_id]).to eq(customer.id)
       expect(result[:plan_code]).to eq(plan.code)
       expect(result[:status]).to eq('active')
@@ -56,7 +56,7 @@
     before { subscription }
 
     it 'terminates a subscription' do
-      delete_with_token(organization, "/api/v1/subscriptions/#{subscription.id}")
+      delete_with_token(organization, "/api/v1/subscriptions/#{subscription.external_id}")
 
       expect(response).to have_http_status(:success)
 
@@ -83,7 +83,7 @@
     before { subscription }
 
     it 'updates a subscription' do
-      put_with_token(organization, "/api/v1/subscriptions/#{subscription.id}", { subscription: update_params })
+      put_with_token(organization, "/api/v1/subscriptions/#{subscription.external_id}", { subscription: update_params })
 
       expect(response).to have_http_status(:success)
 
@@ -108,7 +108,7 @@
     before { subscription1 }
 
     it 'returns subscriptions' do
-      get_with_token(organization, "/api/v1/subscriptions?customer_id=#{customer.customer_id}")
+      get_with_token(organization, "/api/v1/subscriptions?external_customer_id=#{customer.external_id}")
 
       expect(response).to have_http_status(:success)
 
@@ -125,7 +125,7 @@
       before { subscription2 }
 
       it 'returns subscriptions with correct meta data' do
-        get_with_token(organization, "/api/v1/subscriptions?customer_id=#{customer.customer_id}&page=1&per_page=1")
+        get_with_token(organization, "/api/v1/subscriptions?external_customer_id=#{customer.external_id}&page=1&per_page=1")
 
         expect(response).to have_http_status(:success)
 
@@ -142,7 +142,7 @@
 
     context 'with invalid customer' do
       it 'returns not_found error' do
-        get_with_token(organization, '/api/v1/subscriptions?customer_id=invalid')
+        get_with_token(organization, '/api/v1/subscriptions?external_customer_id=invalid')
 
         expect(response).to have_http_status(:not_found)
       end
diff --git a/spec/serializers/v1/payment_providers/customer_error_serializer_spec.rb b/spec/serializers/v1/payment_providers/customer_error_serializer_spec.rb
index 9ae817429db..e79ef8b2002 100644
--- a/spec/serializers/v1/payment_providers/customer_error_serializer_spec.rb
+++ b/spec/serializers/v1/payment_providers/customer_error_serializer_spec.rb
@@ -20,7 +20,7 @@
 
     aggregate_failures do
       expect(result['data']['lago_customer_id']).to eq(customer.id)
-      expect(result['data']['customer_id']).to eq(customer.customer_id)
+      expect(result['data']['external_customer_id']).to eq(customer.external_id)
       expect(result['data']['payment_provider']).to eq(customer.payment_provider)
       expect(result['data']['provider_error']).to eq(options[:provider_error])
     end
diff --git a/spec/serializers/v1/payment_providers/invoice_payment_error_serializer_spec.rb b/spec/serializers/v1/payment_providers/invoice_payment_error_serializer_spec.rb
index c93ec23d7d2..c9f50ac5243 100644
--- a/spec/serializers/v1/payment_providers/invoice_payment_error_serializer_spec.rb
+++ b/spec/serializers/v1/payment_providers/invoice_payment_error_serializer_spec.rb
@@ -22,7 +22,7 @@
     aggregate_failures do
       expect(result['data']['lago_invoice_id']).to eq(invoice.id)
       expect(result['data']['lago_customer_id']).to eq(invoice.customer.id)
-      expect(result['data']['customer_id']).to eq(invoice.customer.customer_id)
+      expect(result['data']['external_customer_id']).to eq(invoice.customer.external_id)
       expect(result['data']['provider_customer_id']).to eq(options[:provider_customer_id])
       expect(result['data']['payment_provider']).to eq(invoice.customer.payment_provider)
       expect(result['data']['provider_error']).to eq(options[:provider_error])
diff --git a/spec/services/applied_add_ons/create_service_spec.rb b/spec/services/applied_add_ons/create_service_spec.rb
index fac25032d86..ee37e2e3992 100644
--- a/spec/services/applied_add_ons/create_service_spec.rb
+++ b/spec/services/applied_add_ons/create_service_spec.rb
@@ -114,12 +114,12 @@
 
   describe 'create_from_api' do
     let(:add_on_code) { add_on&.code }
-    let(:external_customer_id) { customer&.customer_id }
+    let(:external_customer_id) { customer&.external_id }
 
     let(:create_args) do
       {
         add_on_code: add_on_code,
-        customer_id: external_customer_id,
+        external_customer_id: external_customer_id,
         amount_cents: amount_cents,
         amount_currency: amount_currency,
       }
@@ -180,7 +180,7 @@
 
     context 'when customer is not found' do
       let(:customer) { nil }
-      let(:customer_id) { 'foo' }
+      let(:external_customer_id) { 'foo' }
 
       it { expect(create_result).not_to be_success }
       it { expect(create_result.error_code).to eq('missing_argument') }
diff --git a/spec/services/applied_coupons/create_service_spec.rb b/spec/services/applied_coupons/create_service_spec.rb
index 9e3a40a50e8..040961dae7e 100644
--- a/spec/services/applied_coupons/create_service_spec.rb
+++ b/spec/services/applied_coupons/create_service_spec.rb
@@ -135,12 +135,12 @@
 
   describe 'create_from_api' do
     let(:coupon_code) { coupon&.code }
-    let(:external_customer_id) { customer&.customer_id }
+    let(:external_customer_id) { customer&.external_id }
 
     let(:create_args) do
       {
         coupon_code: coupon_code,
-        customer_id: external_customer_id,
+        external_customer_id: external_customer_id,
         amount_cents: amount_cents,
         amount_currency: amount_currency,
       }
@@ -198,7 +198,7 @@
 
     context 'when customer is not found' do
       let(:customer) { nil }
-      let(:customer_id) { 'foo' }
+      let(:external_customer_id) { 'foo' }
 
       it { expect(create_result).not_to be_success }
       it { expect(create_result.error_code).to eq('missing_argument') }
diff --git a/spec/services/customers/create_service_spec.rb b/spec/services/customers/create_service_spec.rb
index 2b31f1d5d44..89b06ad0904 100644
--- a/spec/services/customers/create_service_spec.rb
+++ b/spec/services/customers/create_service_spec.rb
@@ -12,7 +12,7 @@
   describe 'create_from_api' do
     let(:create_args) do
       {
-        customer_id: SecureRandom.uuid,
+        external_id: SecureRandom.uuid,
         name: 'Foo Bar',
       }
     end
@@ -32,7 +32,7 @@
       customer = result.customer
       expect(customer.id).to be_present
       expect(customer.organization_id).to eq(organization.id)
-      expect(customer.customer_id).to eq(create_args[:customer_id])
+      expect(customer.external_id).to eq(create_args[:external_id])
       expect(customer.name).to eq(create_args[:name])
     end
 
@@ -59,7 +59,7 @@
         create(
           :customer,
           organization: organization,
-          customer_id: create_args[:customer_id],
+          external_id: create_args[:external_id],
           email: 'foo@bar.com',
         )
       end
@@ -74,7 +74,7 @@
           expect(result).to be_success
           expect(result.customer).to eq(customer)
           expect(result.customer.name).to eq(create_args[:name])
-          expect(result.customer.customer_id).to eq(create_args[:customer_id])
+          expect(result.customer.external_id).to eq(create_args[:external_id])
 
           # NOTE: It should not erase exsting properties
           expect(result.customer.country).to eq(customer.country)
@@ -113,7 +113,7 @@
     context 'with stripe configuration' do
       let(:create_args) do
         {
-          customer_id: SecureRandom.uuid,
+          external_id: SecureRandom.uuid,
           name: 'Foo Bar',
           billing_configuration: {
             payment_provider: 'stripe',
@@ -147,7 +147,7 @@
     context 'with unknown payment provider' do
       let(:create_args) do
         {
-          customer_id: SecureRandom.uuid,
+          external_id: SecureRandom.uuid,
           name: 'Foo Bar',
           billing_configuration: {
             payment_provider: 'foo',
@@ -202,7 +202,7 @@
           create(
             :customer,
             organization: organization,
-            customer_id: create_args[:customer_id],
+            external_id: create_args[:external_id],
             email: 'foo@bar.com',
           )
         end
@@ -229,7 +229,7 @@
   describe 'create' do
     let(:create_args) do
       {
-        customer_id: SecureRandom.uuid,
+        external_id: SecureRandom.uuid,
         name: 'Foo Bar',
         organization_id: organization.id,
       }
@@ -248,7 +248,7 @@
         customer = result.customer
         expect(customer.id).to be_present
         expect(customer.organization_id).to eq(organization.id)
-        expect(customer.customer_id).to eq(create_args[:customer_id])
+        expect(customer.external_id).to eq(create_args[:external_id])
         expect(customer.name).to eq(create_args[:name])
       end
     end
@@ -270,7 +270,7 @@
 
     context 'when customer already exists' do
       let(:customer) do
-        create(:customer, organization: organization, customer_id: create_args[:customer_id])
+        create(:customer, organization: organization, external_id: create_args[:external_id])
       end
 
       before { customer }
@@ -321,7 +321,7 @@
       context 'with provider customer id' do
         let(:create_args) do
           {
-            customer_id: SecureRandom.uuid,
+            external_id: SecureRandom.uuid,
             name: 'Foo Bar',
             organization_id: organization.id,
             payment_provider: 'stripe',
diff --git a/spec/services/customers/update_service_spec.rb b/spec/services/customers/update_service_spec.rb
index 738bbd3b52a..487deef5984 100644
--- a/spec/services/customers/update_service_spec.rb
+++ b/spec/services/customers/update_service_spec.rb
@@ -13,13 +13,13 @@
     let(:user) { membership.user }
 
     let(:customer) { create(:customer, organization: organization) }
-    let(:customer_id) { SecureRandom.uuid }
+    let(:external_id) { SecureRandom.uuid }
 
     let(:update_args) do
       {
         id: customer.id,
         name: 'Updated customer name',
-        customer_id: customer_id,
+        external_id: external_id,
       }
     end
 
@@ -33,7 +33,7 @@
     end
 
     context 'with validation error' do
-      let(:customer_id) { nil }
+      let(:external_id) { nil }
 
       it 'returns an error' do
         result = customers_service.update(**update_args)
@@ -54,7 +54,7 @@
         updated_customer = result.customer
         aggregate_failures do
           expect(updated_customer.name).to eq('Updated customer name')
-          expect(updated_customer.customer_id).to eq(customer.customer_id)
+          expect(updated_customer.external_id).to eq(customer.external_id)
         end
       end
     end
@@ -64,7 +64,7 @@
         {
           id: customer.id,
           name: 'Updated customer name',
-          customer_id: customer_id,
+          external_id: external_id,
           payment_provider: 'stripe',
         }
       end
@@ -85,7 +85,7 @@
         let(:update_args) do
           {
             id: customer.id,
-            customer_id: SecureRandom.uuid,
+            external_id: SecureRandom.uuid,
             name: 'Foo Bar',
             organization_id: organization.id,
             payment_provider: 'stripe',
@@ -111,7 +111,7 @@
           let(:update_args) do
             {
               id: customer.id,
-              customer_id: SecureRandom.uuid,
+              external_id: SecureRandom.uuid,
               name: 'Foo Bar',
               organization_id: organization.id,
               payment_provider: nil,
diff --git a/spec/services/events/create_batch_service_spec.rb b/spec/services/events/create_batch_service_spec.rb
index 83d83585b6e..2bf1747bbfa 100644
--- a/spec/services/events/create_batch_service_spec.rb
+++ b/spec/services/events/create_batch_service_spec.rb
@@ -6,14 +6,14 @@
   subject(:create_batch_service) { described_class.new }
 
   let(:organization) { create(:organization) }
-  let(:billable_metric)  { create(:billable_metric, organization: organization) }
+  let(:billable_metric) { create(:billable_metric, organization: organization) }
   let(:customer) { create(:customer, organization: organization) }
 
   describe '#validate_params' do
     let(:event_arguments) do
       {
         transaction_id: SecureRandom.uuid,
-        subscription_ids: %w[id1 id2],
+        external_subscription_ids: %w[id1 id2],
         code: 'foo',
       }
     end
@@ -40,7 +40,7 @@
           expect(result.error_code).to eq('missing_mandatory_param')
           expect(result.error_details).to include(:transaction_id)
           expect(result.error_details).to include(:code)
-          expect(result.error_details).to include(:subscription_ids)
+          expect(result.error_details).to include(:external_subscription_ids)
         end
       end
     end
@@ -53,7 +53,7 @@
 
     let(:create_args) do
       {
-        subscription_ids: [subscription.id, subscription2.id],
+        external_subscription_ids: [subscription.external_id, subscription2.external_id],
         code: billable_metric.code,
         transaction_id: transaction_id,
         properties: { foo: 'bar' },
diff --git a/spec/services/events/create_service_spec.rb b/spec/services/events/create_service_spec.rb
index 5d0f7dfaf8a..e7ac5287c56 100644
--- a/spec/services/events/create_service_spec.rb
+++ b/spec/services/events/create_service_spec.rb
@@ -13,7 +13,7 @@
     let(:params) do
       {
         transaction_id: SecureRandom.uuid,
-        customer_id: SecureRandom.uuid,
+        external_customer_id: SecureRandom.uuid,
         code: 'foo',
       }
     end
@@ -27,7 +27,7 @@
     context 'with missing or nil arguments' do
       let(:params) do
         {
-          customer_id: SecureRandom.uuid,
+          external_customer_id: SecureRandom.uuid,
           code: nil,
         }
       end
@@ -45,13 +45,13 @@
       end
     end
 
-    context 'when customer_id and subscription_id but multiple subscriptions' do
+    context 'when external_customer_id and subscription_id but multiple subscriptions' do
       let(:subscription) { create(:subscription, customer: customer) }
       let(:params) do
         {
           transaction_id: SecureRandom.uuid,
-          customer_id: customer.customer_id,
-          subscription_id: subscription.id,
+          external_customer_id: customer.external_id,
+          external_subscription_id: subscription.external_id,
           code: 'code'
         }
       end
@@ -67,11 +67,11 @@
       end
     end
 
-    context 'when only customer_id but multiple subscriptions' do
+    context 'when only external_customer_id but multiple subscriptions' do
       let(:params) do
         {
           transaction_id: SecureRandom.uuid,
-          customer_id: customer.customer_id,
+          external_customer_id: customer.external_id,
           code: 'code'
         }
       end
@@ -87,7 +87,7 @@
 
         aggregate_failures do
           expect(result.error_code).to eq('missing_mandatory_param')
-          expect(result.error_details).to include(:subscription_id)
+          expect(result.error_details).to include(:external_subscription_id)
         end
       end
     end
@@ -98,7 +98,7 @@
 
     let(:create_args) do
       {
-        customer_id: customer.customer_id,
+        external_customer_id: customer.external_id,
         code: billable_metric.code,
         transaction_id: SecureRandom.uuid,
         properties: { foo: 'bar' },
@@ -137,7 +137,7 @@
         {
           code: billable_metric.code,
           transaction_id: SecureRandom.uuid,
-          subscription_id: subscription.id,
+          external_subscription_id: subscription.external_id,
           properties: { foo: 'bar' },
           timestamp: Time.zone.now.to_i,
         }
@@ -172,7 +172,7 @@
         {
           code: billable_metric.code,
           transaction_id: SecureRandom.uuid,
-          subscription_id: subscription2.id,
+          external_subscription_id: subscription2.external_id,
           properties: { foo: 'bar' },
           timestamp: Time.zone.now.to_i,
         }
@@ -200,10 +200,11 @@
 
     context 'when event already exists' do
       let(:existing_event) do
-        create(:event,
-               organization: organization,
-               transaction_id: create_args[:transaction_id],
-               subscription_id: subscription.id
+        create(
+          :event,
+          organization: organization,
+          transaction_id: create_args[:transaction_id],
+          subscription_id: subscription.id
         )
       end
 
@@ -224,7 +225,7 @@
     context 'when properties are empty' do
       let(:create_args) do
         {
-          customer_id: customer.customer_id,
+          external_customer_id: customer.external_id,
           code: billable_metric.code,
           transaction_id: SecureRandom.uuid,
           timestamp: Time.zone.now.to_i,
diff --git a/spec/services/events/validate_creation_service_spec.rb b/spec/services/events/validate_creation_service_spec.rb
index facce76dc36..02ce33377ba 100644
--- a/spec/services/events/validate_creation_service_spec.rb
+++ b/spec/services/events/validate_creation_service_spec.rb
@@ -18,16 +18,16 @@
   let(:customer) { create(:customer, organization: organization) }
   let(:billable_metric) { create(:billable_metric, organization: organization) }
   let(:params) do
-    { customer_id: customer.customer_id, code: billable_metric.code }
+    { external_customer_id: customer.external_id, code: billable_metric.code }
   end
 
   describe '.call' do
     let!(:subscription) { create(:active_subscription, customer: customer, organization: organization) }
 
-    context "when batch is false" do
+    context 'when batch is false' do
       let(:batch) { false }
 
-      context 'when customer has only one active subscription and subscription_id is not given' do
+      context 'when customer has only one active subscription and external_subscription_id is not given' do
         it 'does not return any validation errors' do
           expect(validate_event).to be_nil
           expect(result).to be_success
@@ -36,7 +36,7 @@
 
       context 'when customer has only one active subscription and customer is not given' do
         let(:params) do
-          { code: billable_metric.code, subscription_id: subscription.id }
+          { code: billable_metric.code, external_subscription_id: subscription.external_id }
         end
 
         it 'does not return any validation errors' do
@@ -49,7 +49,7 @@
         before { create(:active_subscription, customer: customer, organization: organization) }
 
         let(:params) do
-          { code: billable_metric.code, subscription_id: subscription.id }
+          { code: billable_metric.code, external_subscription_id: subscription.external_id }
         end
 
         it 'does not return any validation errors' do
@@ -84,7 +84,7 @@
         end
       end
 
-      context 'when there are two active subscriptions but subscription_id is not given' do
+      context 'when there are two active subscriptions but external_subscription_id is not given' do
         before do
           create(:active_subscription, customer: customer, organization: organization)
         end
@@ -101,12 +101,12 @@
         end
       end
 
-      context 'when there are two active subscriptions but subscription_id is invalid' do
+      context 'when there are two active subscriptions but external_subscription_id is invalid' do
         let(:params) do
           {
             code: billable_metric.code,
-            subscription_id: SecureRandom.uuid,
-            customer_id: customer.customer_id
+            external_subscription_id: SecureRandom.uuid,
+            external_customer_id: customer.external_id
           }
         end
 
@@ -118,7 +118,7 @@
           validate_event
 
           expect(result).not_to be_success
-          expect(result.error).to eq('subscription_id is invalid')
+          expect(result.error).to eq('external_subscription_id is invalid')
         end
 
         it 'enqueues a SendWebhookJob' do
@@ -128,7 +128,7 @@
 
       context 'when code does not exist' do
         let(:params) do
-          { customer_id: customer.customer_id, code: 'event_code' }
+          { external_customer_id: customer.external_id, code: 'event_code' }
         end
 
         it 'returns code does not exist error' do
@@ -144,12 +144,12 @@
       end
     end
 
-    context "when batch is true" do
+    context 'when batch is true' do
       let(:batch) { true }
 
       context 'when everything is passing' do
         let(:params) do
-          { subscription_ids: [subscription.id], code: billable_metric.code }
+          { external_subscription_ids: [subscription.external_id], code: billable_metric.code }
         end
 
         it 'does not return any validation errors' do
@@ -158,9 +158,9 @@
         end
       end
 
-      context 'when subscription_ids is blank' do
+      context 'when external_subscription_ids is blank' do
         let(:params) do
-          { subscription_ids: [] }
+          { external_subscription_ids: [] }
         end
 
         it 'returns subscription is not given error' do
@@ -177,7 +177,7 @@
 
       context 'when customer is not given' do
         let(:params) do
-          { code: billable_metric.code, subscription_ids: [SecureRandom.uuid] }
+          { code: billable_metric.code, external_subscription_ids: [SecureRandom.uuid] }
         end
 
         let(:validate_event) do
@@ -206,8 +206,8 @@
         let(:params) do
           {
             code: billable_metric.code,
-            subscription_ids: [SecureRandom.uuid],
-            customer_id: customer.customer_id
+            external_subscription_ids: [SecureRandom.uuid],
+            external_customer_id: customer.external_id
           }
         end
 
@@ -219,7 +219,7 @@
           validate_event
 
           expect(result).not_to be_success
-          expect(result.error).to eq('subscription_id is invalid')
+          expect(result.error).to eq('external_subscription_id is invalid')
         end
 
         it 'enqueues a SendWebhookJob' do
@@ -231,8 +231,8 @@
         let(:params) do
           {
             code: 'event_code',
-            subscription_ids: [subscription.id],
-            customer_id: customer.customer_id
+            external_subscription_ids: [subscription.external_id],
+            external_customer_id: customer.external_id
           }
         end
 
diff --git a/spec/services/subscriptions/create_service_spec.rb b/spec/services/subscriptions/create_service_spec.rb
index 56383806bf4..db7a6d64aea 100644
--- a/spec/services/subscriptions/create_service_spec.rb
+++ b/spec/services/subscriptions/create_service_spec.rb
@@ -14,7 +14,7 @@
 
     let(:params) do
       {
-        customer_id: customer.customer_id,
+        external_customer_id: customer.external_id,
         plan_code: plan.code,
         name: 'invoice display name',
         external_id: external_id,
@@ -48,6 +48,27 @@
       end
     end
 
+    it 'calls SegmentTrackJob' do
+      subscription = create_service.create_from_api(
+        organization: organization,
+        params: params,
+      ).subscription
+
+      expect(SegmentTrackJob).to have_received(:perform_later).with(
+        membership_id: CurrentContext.membership,
+        event: 'subscription_created',
+        properties: {
+          created_at: subscription.created_at,
+          customer_id: subscription.customer_id,
+          plan_code: subscription.plan.code,
+          plan_name: subscription.plan.name,
+          subscription_type: 'create',
+          organization_id: subscription.organization.id,
+          billing_time: 'anniversary',
+        },
+      )
+    end
+
     context 'when external_id is not given' do
       let(:external_id) { nil }
 
@@ -57,14 +78,14 @@
           params: params,
         )
 
-        expect(result.subscription.external_id).to eq(customer.customer_id)
+        expect(result.subscription.external_id).to eq(customer.external_id)
       end
     end
 
     context 'when billing_time is not provided' do
       let(:params) do
         {
-          customer_id: customer.customer_id,
+          external_customer_id: customer.external_id,
           plan_code: plan.code,
           name: 'invoice display name',
           external_id: external_id,
@@ -85,31 +106,10 @@
       end
     end
 
-    it 'calls SegmentTrackJob' do
-      subscription = create_service.create_from_api(
-        organization: organization,
-        params: params,
-      ).subscription
-
-      expect(SegmentTrackJob).to have_received(:perform_later).with(
-        membership_id: CurrentContext.membership,
-        event: 'subscription_created',
-        properties: {
-          created_at: subscription.created_at,
-          customer_id: subscription.customer_id,
-          plan_code: subscription.plan.code,
-          plan_name: subscription.plan.name,
-          subscription_type: 'create',
-          organization_id: subscription.organization.id,
-          billing_time: 'anniversary',
-        },
-      )
-    end
-
     context 'when customer does not exists' do
       let(:params) do
         {
-          customer_id: SecureRandom.uuid,
+          external_customer_id: SecureRandom.uuid,
           plan_code: plan.code,
           external_id: external_id,
         }
@@ -126,7 +126,7 @@
         subscription = result.subscription
 
         aggregate_failures do
-          expect(subscription.customer.customer_id).to eq(params[:customer_id])
+          expect(subscription.customer.external_id).to eq(params[:external_customer_id])
           expect(subscription.plan_id).to eq(plan.id)
           expect(subscription.started_at).to be_present
           expect(subscription.subscription_date).to be_present
@@ -148,10 +148,10 @@
       end
     end
 
-    context 'when customer id is missing' do
+    context 'when external customer id is missing' do
       let(:params) do
         {
-          customer_id: nil,
+          external_customer_id: nil,
           plan_code: plan.code,
           external_id: external_id,
         }
@@ -168,10 +168,10 @@
       end
     end
 
-    context 'when plan doest not exists' do
+    context 'when plan does not exists' do
       let(:params) do
         {
-          customer_id: customer.customer_id,
+          external_customer_id: customer.external_id,
           plan_code: 'invalid_plan',
           external_id: external_id,
         }
@@ -191,7 +191,7 @@
     context 'when billing_time is invalid' do
       let(:params) do
         {
-          customer_id: customer.id,
+          external_customer_id: customer.id,
           plan_code: plan.code,
           external_id: external_id,
           billing_time: :foo,
@@ -216,10 +216,9 @@
     context 'when an active subscription already exists' do
       let(:params) do
         {
-          customer_id: customer.customer_id,
+          external_customer_id: customer.external_id,
           plan_code: plan.code,
           name: 'invoice display name',
-          subscription_id: subscription.id,
           external_id: external_id,
         }
       end
@@ -236,22 +235,10 @@
 
       before { subscription }
 
-      context 'when subscription_id is given' do
-        it 'returns existing subscription' do
-          result = create_service.create_from_api(
-            organization: organization,
-            params: params,
-          )
-
-          expect(result).to be_success
-          expect(result.subscription.id).to eq(subscription.id)
-        end
-      end
-
-      context 'when external_id is given but not subscription_id' do
+      context 'when external_id is given' do
         let(:params) do
           {
-            customer_id: customer.customer_id,
+            external_customer_id: customer.external_id,
             plan_code: plan.code,
             name: 'invoice display name',
             external_id: external_id,
@@ -271,17 +258,17 @@
         end
       end
 
-      context 'when subscription_id and external_id are not given' do
+      context 'when external_id is not given' do
         let(:params) do
           {
-            customer_id: customer.customer_id,
+            external_customer_id: customer.external_id,
             plan_code: plan.code,
             name: 'invoice display name',
           }
         end
 
         it 'returns existing subscription' do
-          subscription.update!(external_id: customer.customer_id)
+          subscription.update!(external_id: customer.external_id)
 
           result = create_service.create_from_api(
             organization: organization,
@@ -297,7 +284,7 @@
         let(:new_plan) { create(:plan, amount_cents: 200, organization: organization, amount_currency: 'USD') }
         let(:params) do
           {
-            customer_id: customer.customer_id,
+            external_customer_id: customer.external_id,
             plan_code: new_plan.code,
             name: 'invoice display name new',
             external_id: external_id,
@@ -320,11 +307,10 @@
           let(:higher_plan) { create(:plan, amount_cents: 200, organization: organization) }
           let(:params) do
             {
-              customer_id: customer.customer_id,
+              external_customer_id: customer.external_id,
               plan_code: higher_plan.code,
               name: 'invoice display name new',
-              subscription_id: subscription.id,
-              external_id: external_id,
+              external_id: subscription.external_id,
             }
           end
 
@@ -334,6 +320,7 @@
               params: params,
             )
 
+
             old_subscription = Subscription.find(subscription.id)
 
             expect(old_subscription).to be_terminated
@@ -415,11 +402,10 @@
 
           let(:params) do
             {
-              customer_id: customer.customer_id,
+              external_customer_id: customer.external_id,
               plan_code: lower_plan.code,
               name: 'invoice display name new',
-              subscription_id: subscription.id,
-              external_id: external_id,
+              external_id: subscription.external_id,
             }
           end
 
diff --git a/spec/services/subscriptions/terminate_service_spec.rb b/spec/services/subscriptions/terminate_service_spec.rb
index d2645a74304..2d9fe04ba61 100644
--- a/spec/services/subscriptions/terminate_service_spec.rb
+++ b/spec/services/subscriptions/terminate_service_spec.rb
@@ -66,7 +66,7 @@
     it 'terminates a subscription' do
       result = terminate_service.terminate_from_api(
         organization: organization,
-        subscription_id: subscription.id
+        external_id: subscription.external_id
       )
 
       aggregate_failures do
@@ -78,7 +78,10 @@
 
     it 'enqueues a BillSubscriptionJob' do
       expect do
-        terminate_service.terminate(subscription.id)
+        terminate_service.terminate_from_api(
+          organization: organization,
+          external_id: subscription.external_id
+        )
       end.to have_enqueued_job(BillSubscriptionJob)
     end
 
@@ -86,7 +89,7 @@
       it 'returns an error' do
         result = terminate_service.terminate_from_api(
           organization: organization,
-          subscription_id: subscription.id + '123'
+          external_id: subscription.external_id + '123'
         )
 
         expect(result.error_code).to eq('not_found')
diff --git a/spec/services/subscriptions/update_service_spec.rb b/spec/services/subscriptions/update_service_spec.rb
index 76fa5eafa74..3bb44ec3024 100644
--- a/spec/services/subscriptions/update_service_spec.rb
+++ b/spec/services/subscriptions/update_service_spec.rb
@@ -61,7 +61,7 @@
     it 'updates the subscription' do
       result = update_service.update_from_api(
         organization: organization,
-        id: subscription.id,
+        external_id: subscription.external_id,
         params: update_args
       )
 
@@ -72,11 +72,11 @@
       end
     end
 
-    context 'with invalid id' do
+    context 'with invalid external_id' do
       it 'returns an error' do
         result = update_service.update_from_api(
           organization: organization,
-          id: subscription.id + '123',
+          external_id: subscription.external_id + '123',
           params: update_args
         )
 
diff --git a/spec/services/webhooks/event_service_spec.rb b/spec/services/webhooks/event_service_spec.rb
index 45df5f6fd55..7ce7d9100a6 100644
--- a/spec/services/webhooks/event_service_spec.rb
+++ b/spec/services/webhooks/event_service_spec.rb
@@ -10,7 +10,7 @@
   let(:object) do
     {
       input_params: {
-        customer_id: 'customer',
+        external_customer_id: 'customer',
         transaction_id: SecureRandom.uuid,
         code: 'code'
       },

From 58c051e083f749a34d167b083167e564e6227a97 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Romain=20Semp=C3=A9?= <romain@getlago.com>
Date: Wed, 31 Aug 2022 10:50:52 +0200
Subject: [PATCH 3/9] misc: Add index for external_id on subscriptions

---
 app/services/payment_provider_customers/create_service.rb       | 2 +-
 ...23145421_rename_unique_id_to_external_id_on_subscriptions.rb | 1 +
 db/schema.rb                                                    | 1 +
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/app/services/payment_provider_customers/create_service.rb b/app/services/payment_provider_customers/create_service.rb
index 2b9a5a799c9..7f6ae441a11 100644
--- a/app/services/payment_provider_customers/create_service.rb
+++ b/app/services/payment_provider_customers/create_service.rb
@@ -10,7 +10,7 @@ def initialize(customer)
 
     def create_or_update(customer_class:, payment_provider_id:, params:, async: true)
       provider_customer = customer_class.find_or_initialize_by(
-        customer_id: customer.id, # TODO: Why?
+        customer_id: customer.id,
         payment_provider_id: payment_provider_id,
       )
 
diff --git a/db/migrate/20220823145421_rename_unique_id_to_external_id_on_subscriptions.rb b/db/migrate/20220823145421_rename_unique_id_to_external_id_on_subscriptions.rb
index b8117802d9c..497502ce8d6 100644
--- a/db/migrate/20220823145421_rename_unique_id_to_external_id_on_subscriptions.rb
+++ b/db/migrate/20220823145421_rename_unique_id_to_external_id_on_subscriptions.rb
@@ -1,5 +1,6 @@
 class RenameUniqueIdToExternalIdOnSubscriptions < ActiveRecord::Migration[7.0]
   def change
     rename_column :subscriptions, :unique_id, :external_id
+    add_index :subscriptions, :external_id
   end
 end
diff --git a/db/schema.rb b/db/schema.rb
index ee7d0680210..935c534f89d 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -349,6 +349,7 @@
     t.string "external_id", null: false
     t.integer "billing_time", default: 0, null: false
     t.index ["customer_id"], name: "index_subscriptions_on_customer_id"
+    t.index ["external_id"], name: "index_subscriptions_on_external_id"
     t.index ["plan_id"], name: "index_subscriptions_on_plan_id"
   end
 

From 70a38f5502d861bad2e9bcd4e2baf2b10c7742b8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Romain=20Semp=C3=A9?= <romain@getlago.com>
Date: Wed, 31 Aug 2022 17:27:31 +0200
Subject: [PATCH 4/9] misc: Rename customer_id to external_customer_id on
 wallets

---
 app/controllers/api/v1/wallets_controller.rb               | 4 ++--
 spec/requests/api/v1/wallets_spec.rb                       | 6 +++---
 spec/services/wallet_transactions/validate_service_spec.rb | 2 +-
 spec/services/wallets/create_service_spec.rb               | 2 +-
 4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/app/controllers/api/v1/wallets_controller.rb b/app/controllers/api/v1/wallets_controller.rb
index 52ae6af997b..5fe7bdbe018 100644
--- a/app/controllers/api/v1/wallets_controller.rb
+++ b/app/controllers/api/v1/wallets_controller.rb
@@ -57,7 +57,7 @@ def show
       end
 
       def index
-        customer = Customer.find_by(customer_id: params[:external_customer_id])
+        customer = Customer.find_by(external_id: params[:external_customer_id])
 
         return not_found_error unless customer
 
@@ -99,7 +99,7 @@ def update_params
       end
 
       def customer
-        Customer.find_by(customer_id: customer_params[:external_customer_id], organization_id: current_organization.id)
+        Customer.find_by(external_id: customer_params[:external_customer_id], organization_id: current_organization.id)
       end
 
       def render_wallet(wallet)
diff --git a/spec/requests/api/v1/wallets_spec.rb b/spec/requests/api/v1/wallets_spec.rb
index 5a3eba4cb89..906fe476461 100644
--- a/spec/requests/api/v1/wallets_spec.rb
+++ b/spec/requests/api/v1/wallets_spec.rb
@@ -12,7 +12,7 @@
   describe 'create' do
     let(:create_params) do
       {
-        external_customer_id: customer.customer_id,
+        external_customer_id: customer.external_id,
         rate_amount: '1',
         name: 'Wallet1',
         paid_credits: '10',
@@ -135,7 +135,7 @@
     before { wallet }
 
     it 'returns wallets' do
-      get_with_token(organization, "/api/v1/wallets?external_customer_id=#{customer.customer_id}")
+      get_with_token(organization, "/api/v1/wallets?external_customer_id=#{customer.external_id}")
 
       expect(response).to have_http_status(:success)
 
@@ -152,7 +152,7 @@
       before { wallet2 }
 
       it 'returns wallets with correct meta data' do
-        get_with_token(organization, "/api/v1/wallets?external_customer_id=#{customer.customer_id}&page=1&per_page=1")
+        get_with_token(organization, "/api/v1/wallets?external_customer_id=#{customer.external_id}&page=1&per_page=1")
 
         expect(response).to have_http_status(:success)
 
diff --git a/spec/services/wallet_transactions/validate_service_spec.rb b/spec/services/wallet_transactions/validate_service_spec.rb
index 3f03a6f4b9b..3b5afc498d2 100644
--- a/spec/services/wallet_transactions/validate_service_spec.rb
+++ b/spec/services/wallet_transactions/validate_service_spec.rb
@@ -17,7 +17,7 @@
   let(:args) do
     {
       wallet_id: wallet_id,
-      customer_id: customer.customer_id,
+      customer_id: customer.external_id,
       organization_id: organization.id,
       paid_credits: paid_credits,
       granted_credits: granted_credits,
diff --git a/spec/services/wallets/create_service_spec.rb b/spec/services/wallets/create_service_spec.rb
index b401a78514a..d489012e255 100644
--- a/spec/services/wallets/create_service_spec.rb
+++ b/spec/services/wallets/create_service_spec.rb
@@ -7,7 +7,7 @@
 
   let(:membership) { create(:membership) }
   let(:organization) { membership.organization }
-  let(:customer) { create(:customer, organization: organization, customer_id: 'foobar') }
+  let(:customer) { create(:customer, organization: organization, external_id: 'foobar') }
   let(:subscription) { create(:subscription, customer: customer) }
 
   before { subscription }

From e21bb602686b15e7bb621d25d3219c4af7ab38a9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Romain=20Semp=C3=A9?= <romain@getlago.com>
Date: Thu, 1 Sep 2022 11:36:56 +0200
Subject: [PATCH 5/9] misc: Add external_customer_id on wallet response

---
 app/serializers/v1/wallet_serializer.rb | 2 +-
 spec/requests/api/v1/wallets_spec.rb    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/app/serializers/v1/wallet_serializer.rb b/app/serializers/v1/wallet_serializer.rb
index 7052b6aeb53..c19711b8bcb 100644
--- a/app/serializers/v1/wallet_serializer.rb
+++ b/app/serializers/v1/wallet_serializer.rb
@@ -6,7 +6,7 @@ def serialize
       {
         lago_id: model.id,
         lago_customer_id: model.customer_id,
-        external_customer_id: model.customer.customer_id,
+        external_customer_id: model.customer.external_id,
         status: model.status,
         currency: model.currency,
         name: model.name,
diff --git a/spec/requests/api/v1/wallets_spec.rb b/spec/requests/api/v1/wallets_spec.rb
index 906fe476461..340763b7cd0 100644
--- a/spec/requests/api/v1/wallets_spec.rb
+++ b/spec/requests/api/v1/wallets_spec.rb
@@ -29,7 +29,7 @@
       result = JSON.parse(response.body, symbolize_names: true)[:wallet]
       expect(result[:lago_id]).to be_present
       expect(result[:name]).to eq(create_params[:name])
-      expect(result[:external_customer_id]).to eq(customer.customer_id)
+      expect(result[:external_customer_id]).to eq(customer.external_id)
     end
   end
 

From b410891652d2c2ecc48deae525b9360619da5f28 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Romain=20Semp=C3=A9?= <romain@getlago.com>
Date: Thu, 1 Sep 2022 11:54:12 +0200
Subject: [PATCH 6/9] misc: Put external id as mandatory on subscriptions from
 API

---
 app/models/subscription.rb                    |  3 +-
 app/services/subscriptions/create_service.rb  | 14 +++------
 spec/models/subscription_spec.rb              | 18 ++++++++++--
 spec/requests/api/v1/subscriptions_spec.rb    |  1 +
 .../subscriptions/create_service_spec.rb      | 29 +++----------------
 5 files changed, 27 insertions(+), 38 deletions(-)

diff --git a/app/models/subscription.rb b/app/models/subscription.rb
index 286b4454c9d..4b0bb8a3d1e 100644
--- a/app/models/subscription.rb
+++ b/app/models/subscription.rb
@@ -74,7 +74,8 @@ def already_billed?
   def validate_external_id
     return unless active?
 
-    used_ids = customer&.active_subscriptions&.pluck(:external_id)
+    # NOTE: We want unique external id per organization.
+    used_ids = organization.subscriptions.active.pluck(:external_id)
     errors.add(:external_id, :value_already_exists) if used_ids&.include?(external_id)
   end
 end
diff --git a/app/services/subscriptions/create_service.rb b/app/services/subscriptions/create_service.rb
index debbe5be66a..971bd3ac9c9 100644
--- a/app/services/subscriptions/create_service.rb
+++ b/app/services/subscriptions/create_service.rb
@@ -20,7 +20,7 @@ def create_from_api(organization:, params:)
       @name = params[:name]&.strip
       @external_id = params[:external_id]&.strip
       @billing_time = params[:billing_time]
-      @current_subscription = find_current_subscription
+      @current_subscription = active_subscriptions&.find_by(external_id: external_id)
 
       process_create
     rescue ActiveRecord::RecordInvalid => e
@@ -42,7 +42,8 @@ def create(**args)
       @name = args[:name]&.strip
       @external_id = SecureRandom.uuid
       @billing_time = args[:billing_time]
-      @current_subscription = find_current_subscription(subscription_id: args[:subscription_id])
+      @current_subscription = active_subscriptions&.find_by(id: args[:subscription_id])
+
       process_create
     end
 
@@ -96,7 +97,7 @@ def create_subscription
         plan_id: current_plan.id,
         subscription_date: Time.zone.now.to_date,
         name: name,
-        external_id: external_id || current_customer.external_id,
+        external_id: external_id,
         billing_time: billing_time || :calendar,
       )
       new_subscription.mark_as_active!
@@ -211,12 +212,5 @@ def currency_missmatch?(old_plan, new_plan)
     def active_subscriptions
       @active_subscriptions ||= current_customer&.active_subscriptions
     end
-
-    def find_current_subscription(subscription_id: nil)
-      return active_subscriptions&.find_by(id: subscription_id) if subscription_id
-      return active_subscriptions&.find_by(external_id: external_id) if external_id
-
-      active_subscriptions&.find_by(external_id: current_customer.external_id)
-    end
   end
 end
diff --git a/spec/models/subscription_spec.rb b/spec/models/subscription_spec.rb
index a05b8e60c67..bed8a235211 100644
--- a/spec/models/subscription_spec.rb
+++ b/spec/models/subscription_spec.rb
@@ -120,8 +120,22 @@
     let(:customer) { create(:customer, organization: organization) }
     let(:plan) { create(:plan) }
     let(:external_id) { SecureRandom.uuid }
-    let(:subscription) { create(:active_subscription, plan: plan, customer: customer) }
-    let(:new_subscription) { build(:active_subscription, plan: plan, external_id: external_id, customer: customer) }
+    let(:subscription) do
+      create(
+        :active_subscription,
+        plan: plan,
+        customer: create(:customer, organization: organization)
+      )
+    end
+
+    let(:new_subscription) do
+      build(
+        :active_subscription,
+        plan: plan,
+        external_id: external_id,
+        customer: create(:customer, organization: organization)
+      )
+    end
 
     before { subscription }
 
diff --git a/spec/requests/api/v1/subscriptions_spec.rb b/spec/requests/api/v1/subscriptions_spec.rb
index fbf292458c2..cc1686a42ee 100644
--- a/spec/requests/api/v1/subscriptions_spec.rb
+++ b/spec/requests/api/v1/subscriptions_spec.rb
@@ -26,6 +26,7 @@
       result = JSON.parse(response.body, symbolize_names: true)[:subscription]
 
       expect(result[:lago_id]).to be_present
+      expect(result[:external_id]).to be_present
       expect(result[:external_customer_id]).to eq(customer.external_id)
       expect(result[:lago_customer_id]).to eq(customer.id)
       expect(result[:plan_code]).to eq(plan.code)
diff --git a/spec/services/subscriptions/create_service_spec.rb b/spec/services/subscriptions/create_service_spec.rb
index db7a6d64aea..6c87c11a20a 100644
--- a/spec/services/subscriptions/create_service_spec.rb
+++ b/spec/services/subscriptions/create_service_spec.rb
@@ -43,7 +43,7 @@
         expect(subscription.subscription_date).to be_present
         expect(subscription.name).to eq('invoice display name')
         expect(subscription).to be_active
-        expect(subscription.external_id).to be_present
+        expect(subscription.external_id).to eq(external_id)
         expect(subscription).to be_anniversary
       end
     end
@@ -72,13 +72,14 @@
     context 'when external_id is not given' do
       let(:external_id) { nil }
 
-      it 'sets customer_id as external_id' do
+      it 'returns an error' do
         result = create_service.create_from_api(
           organization: organization,
           params: params,
         )
 
-        expect(result.subscription.external_id).to eq(customer.external_id)
+        expect(result).not_to be_success
+        expect(result.error_details[:external_id]).to eq(['value_is_mandatory'])
       end
     end
 
@@ -258,28 +259,6 @@
         end
       end
 
-      context 'when external_id is not given' do
-        let(:params) do
-          {
-            external_customer_id: customer.external_id,
-            plan_code: plan.code,
-            name: 'invoice display name',
-          }
-        end
-
-        it 'returns existing subscription' do
-          subscription.update!(external_id: customer.external_id)
-
-          result = create_service.create_from_api(
-            organization: organization,
-            params: params,
-          )
-
-          expect(result).to be_success
-          expect(result.subscription.id).to eq(subscription.id)
-        end
-      end
-
       context 'when new plan has different currency than the old plan' do
         let(:new_plan) { create(:plan, amount_cents: 200, organization: organization, amount_currency: 'USD') }
         let(:params) do

From bfe089c5d524f9f246a2e0d47851bec6385683c5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Romain=20Semp=C3=A9?= <romain@getlago.com>
Date: Fri, 2 Sep 2022 09:46:32 +0200
Subject: [PATCH 7/9] misc: Use external_subscription_id on GraphQL event type

---
 app/graphql/types/events/object.rb | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/app/graphql/types/events/object.rb b/app/graphql/types/events/object.rb
index b2dc152515e..51e8df34adf 100644
--- a/app/graphql/types/events/object.rb
+++ b/app/graphql/types/events/object.rb
@@ -7,7 +7,7 @@ class Object < Types::BaseObject
       field :code, String, null: false
 
       field :external_customer_id, String, null: false
-      field :subscription_id, String, null: false
+      field :external_subscription_id, String, null: false
       field :transaction_id, String, null: true
 
       field :timestamp, GraphQL::Types::ISO8601DateTime, null: true
@@ -29,12 +29,16 @@ def external_customer_id
         object.customer.external_id
       end
 
+      def external_subscription_id
+        object.subscription.external_id
+      end
+
       def payload
         {
           event: {
             transaction_id: object.transaction_id,
             external_customer_id: object.customer.external_id,
-            subscription_id: object.subscription_id,
+            external_subscription_id: object.subscription.external_id,
             code: object.code,
             timestamp: object.timestamp.to_i,
             properties: object.properties || {},

From 7269e8d179ea253be1fa6f890187224411b8b860 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Romain=20Semp=C3=A9?= <romain@getlago.com>
Date: Fri, 2 Sep 2022 09:50:04 +0200
Subject: [PATCH 8/9] misc: Add external_id on GraphQL subscription type

---
 app/graphql/types/subscriptions/object.rb |  1 +
 schema.graphql                            |  3 +-
 schema.json                               | 54 +++++++++++++++--------
 3 files changed, 39 insertions(+), 19 deletions(-)

diff --git a/app/graphql/types/subscriptions/object.rb b/app/graphql/types/subscriptions/object.rb
index f32efe360de..4060cdbb2ba 100644
--- a/app/graphql/types/subscriptions/object.rb
+++ b/app/graphql/types/subscriptions/object.rb
@@ -6,6 +6,7 @@ class Object < Types::BaseObject
       graphql_name 'Subscription'
 
       field :id, ID, null: false
+      field :external_id, String, null: false
       field :customer, Types::Customers::Object, null: false
       field :plan, Types::Plans::Object, null: false
 
diff --git a/schema.graphql b/schema.graphql
index 307241e227d..ad0d096d3f9 100644
--- a/schema.graphql
+++ b/schema.graphql
@@ -2621,13 +2621,13 @@ type Event {
   billableMetricName: String
   code: String!
   externalCustomerId: String!
+  externalSubscriptionId: String!
   id: ID!
   ipAddress: String
   matchBillableMetric: Boolean!
   matchCustomField: Boolean!
   payload: JSON!
   receivedAt: ISO8601DateTime!
-  subscriptionId: String!
   timestamp: ISO8601DateTime
   transactionId: String
 }
@@ -3394,6 +3394,7 @@ type Subscription {
   canceledAt: ISO8601DateTime
   createdAt: ISO8601DateTime!
   customer: Customer!
+  externalId: String!
   id: ID!
   name: String
   nextName: String
diff --git a/schema.json b/schema.json
index 59700629dfb..175b7fe6865 100644
--- a/schema.json
+++ b/schema.json
@@ -7844,6 +7844,24 @@
 
               ]
             },
+            {
+              "name": "externalSubscriptionId",
+              "description": null,
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "SCALAR",
+                  "name": "String",
+                  "ofType": null
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null,
+              "args": [
+
+              ]
+            },
             {
               "name": "id",
               "description": null,
@@ -7948,24 +7966,6 @@
 
               ]
             },
-            {
-              "name": "subscriptionId",
-              "description": null,
-              "type": {
-                "kind": "NON_NULL",
-                "name": null,
-                "ofType": {
-                  "kind": "SCALAR",
-                  "name": "String",
-                  "ofType": null
-                }
-              },
-              "isDeprecated": false,
-              "deprecationReason": null,
-              "args": [
-
-              ]
-            },
             {
               "name": "timestamp",
               "description": null,
@@ -12093,6 +12093,24 @@
 
               ]
             },
+            {
+              "name": "externalId",
+              "description": null,
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "SCALAR",
+                  "name": "String",
+                  "ofType": null
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null,
+              "args": [
+
+              ]
+            },
             {
               "name": "id",
               "description": null,

From 7a0be052c3383cbc8546ec21bd8a34866e4d1fcd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Romain=20Semp=C3=A9?= <romain@getlago.com>
Date: Mon, 5 Sep 2022 17:16:59 +0200
Subject: [PATCH 9/9] misc: Use external_id for persisted events

---
 .../billable_metrics/aggregations/recurring_count_service.rb    | 2 +-
 .../aggregations/recurring_count_service_spec.rb                | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/app/services/billable_metrics/aggregations/recurring_count_service.rb b/app/services/billable_metrics/aggregations/recurring_count_service.rb
index 38b285f5490..31a819dfa51 100644
--- a/app/services/billable_metrics/aggregations/recurring_count_service.rb
+++ b/app/services/billable_metrics/aggregations/recurring_count_service.rb
@@ -54,7 +54,7 @@ def base_scope
         PersistedEvent
           .where(billable_metric_id: billable_metric.id)
           .where(customer_id: subscription.customer_id)
-          .where(external_subscription_id: subscription.unique_id)
+          .where(external_subscription_id: subscription.external_id)
       end
 
       # NOTE: Full period duration to take upgrade, terminate
diff --git a/spec/services/billable_metrics/aggregations/recurring_count_service_spec.rb b/spec/services/billable_metrics/aggregations/recurring_count_service_spec.rb
index 8ecdb439b8a..734b5e498db 100644
--- a/spec/services/billable_metrics/aggregations/recurring_count_service_spec.rb
+++ b/spec/services/billable_metrics/aggregations/recurring_count_service_spec.rb
@@ -43,7 +43,7 @@
       customer: customer,
       added_at: added_at,
       removed_at: removed_at,
-      external_subscription_id: subscription.unique_id,
+      external_subscription_id: subscription.external_id,
       billable_metric: billable_metric,
     )
   end