diff --git a/.env.test b/.env.test
index 5df3ed04a..edaead8f8 100644
--- a/.env.test
+++ b/.env.test
@@ -8,6 +8,7 @@ CLAIMS_HOST=claims.localhost
 CLAIMS_HOSTS=claims.localhost
 CLAIMS_DFE_SIGN_IN_CLIENT_ID=123
 CLAIMS_DFE_SIGN_IN_SECRET=secret
+CLAIMS_ESFA_EMAIL_ADDRESSES=esfa@example.com
 
 PLACEMENTS_HOST=placements.localhost
 PLACEMENTS_HOSTS=placements.localhost
diff --git a/app/controllers/claims/payments/claims_controller.rb b/app/controllers/claims/payments/claims_controller.rb
new file mode 100644
index 000000000..e12490c8f
--- /dev/null
+++ b/app/controllers/claims/payments/claims_controller.rb
@@ -0,0 +1,29 @@
+class Claims::Payments::ClaimsController < Claims::ApplicationController
+  skip_before_action :authenticate_user!
+
+  before_action :skip_authorization
+  before_action :validate_token
+  before_action :set_payment
+
+  def download
+    send_data @payment.csv_file.download, filename: "payments-claims-#{Time.current.iso8601}.csv"
+  end
+
+  private
+
+  def validate_token
+    @payment_id = Rails.application.message_verifier(:payments).verify(token_param)
+  rescue ActiveSupport::MessageVerifier::InvalidSignature
+    render "error"
+  end
+
+  def set_payment
+    @payment = Claims::Payment.find(@payment_id)
+  rescue ActiveRecord::RecordNotFound
+    render "error"
+  end
+
+  def token_param
+    params.fetch(:token, nil)
+  end
+end
diff --git a/app/controllers/claims/support/claims/payments/claims_controller.rb b/app/controllers/claims/support/claims/payments/claims_controller.rb
index 40fdb84dd..d5691554d 100644
--- a/app/controllers/claims/support/claims/payments/claims_controller.rb
+++ b/app/controllers/claims/support/claims/payments/claims_controller.rb
@@ -1,4 +1,6 @@
 class Claims::Support::Claims::Payments::ClaimsController < Claims::Support::ApplicationController
+  append_pundit_namespace :claims, :payments
+
   before_action :set_claim, only: %i[show]
   before_action :authorize_claim
 
@@ -11,6 +13,6 @@ def set_claim
   end
 
   def authorize_claim
-    authorize [:payments, @claim || Claims::Claim]
+    authorize @claim || Claims::Claim
   end
 end
diff --git a/app/controllers/claims/support/claims/payments_controller.rb b/app/controllers/claims/support/claims/payments_controller.rb
index fa92c44e9..fc2588b18 100644
--- a/app/controllers/claims/support/claims/payments_controller.rb
+++ b/app/controllers/claims/support/claims/payments_controller.rb
@@ -1,4 +1,6 @@
 class Claims::Support::Claims::PaymentsController < Claims::Support::ApplicationController
+  append_pundit_namespace :claims
+
   before_action :authorize_claims
 
   helper_method :filter_form
@@ -7,6 +9,20 @@ def index
     @pagy, @claims = pagy(filtered_claims)
   end
 
+  def new
+    @submitted_claims = Claims::Claim.submitted
+
+    unless policy(Claims::Payment).create?
+      render "new_not_permitted"
+    end
+  end
+
+  def create
+    Claims::Payment::CreateAndDeliver.call(current_user:)
+
+    redirect_to claims_support_claims_payments_path, flash: { success: true, heading: "Claims sent to ESFA" }
+  end
+
   private
 
   def filtered_claims
@@ -40,6 +56,6 @@ def filter_params
   end
 
   def authorize_claims
-    authorize filtered_claims
+    authorize [:payments, filtered_claims]
   end
 end
diff --git a/app/mailers/claims/payment_mailer.rb b/app/mailers/claims/payment_mailer.rb
new file mode 100644
index 000000000..65710d41c
--- /dev/null
+++ b/app/mailers/claims/payment_mailer.rb
@@ -0,0 +1,24 @@
+class Claims::PaymentMailer < Claims::ApplicationMailer
+  def payment_created_notification(payment)
+    @payment = payment
+
+    notify_email to: esfa_email_addresses,
+                 from: support_email,
+                 subject: t(".subject"),
+                 body: t(
+                   ".body",
+                   download_page_url: claims_payments_claims_url(token:),
+                   support_email:,
+                 )
+  end
+
+  private
+
+  def esfa_email_addresses
+    ENV.fetch("CLAIMS_ESFA_EMAIL_ADDRESSES").split(",")
+  end
+
+  def token
+    Rails.application.message_verifier(:payments).generate(@payment.id, expires_in: 7.days)
+  end
+end
diff --git a/app/models/claims/payment.rb b/app/models/claims/payment.rb
index 36fd66cd8..783fcfefc 100644
--- a/app/models/claims/payment.rb
+++ b/app/models/claims/payment.rb
@@ -19,5 +19,7 @@ class Claims::Payment < ApplicationRecord
   belongs_to :sent_by, class_name: "Claims::SupportUser"
 
   has_many :payment_claims, dependent: :destroy
-  has_many :claims, through: :payment_claims
+  has_many :claims, through: :payment_claims, class_name: "Claims::Claim"
+
+  has_one_attached :csv_file
 end
diff --git a/app/policies/claims/support/claims/payment_policy.rb b/app/policies/claims/support/claims/payment_policy.rb
new file mode 100644
index 000000000..b7ae94b5c
--- /dev/null
+++ b/app/policies/claims/support/claims/payment_policy.rb
@@ -0,0 +1,9 @@
+class Claims::Support::Claims::PaymentPolicy < Claims::ApplicationPolicy
+  def new?
+    true
+  end
+
+  def create?
+    Claims::Claim.submitted.any?
+  end
+end
diff --git a/app/policies/claims/support/claims/payments/claim_policy.rb b/app/policies/claims/support/claims/payments/claim_policy.rb
new file mode 100644
index 000000000..6ebfe3477
--- /dev/null
+++ b/app/policies/claims/support/claims/payments/claim_policy.rb
@@ -0,0 +1,5 @@
+class Claims::Support::Claims::Payments::ClaimPolicy < Claims::ApplicationPolicy
+  def update?
+    false
+  end
+end
diff --git a/app/policies/claims/support/payments/claim_policy.rb b/app/policies/claims/support/payments/claim_policy.rb
deleted file mode 100644
index 1659b7df7..000000000
--- a/app/policies/claims/support/payments/claim_policy.rb
+++ /dev/null
@@ -1,2 +0,0 @@
-class Claims::Support::Payments::ClaimPolicy < Claims::ApplicationPolicy
-end
diff --git a/app/services/claims/payment/create_and_deliver.rb b/app/services/claims/payment/create_and_deliver.rb
new file mode 100644
index 000000000..d3887df5a
--- /dev/null
+++ b/app/services/claims/payment/create_and_deliver.rb
@@ -0,0 +1,33 @@
+class Claims::Payment::CreateAndDeliver < ApplicationService
+  def initialize(current_user:)
+    @current_user = current_user
+  end
+
+  def call
+    return if submitted_claims.none?
+
+    ActiveRecord::Base.transaction do |transaction|
+      csv_file = Claims::Payments::Claim::GenerateCSVFile.call(claims: submitted_claims)
+
+      payment = Claims::Payment.create!(sent_by: current_user, csv_file: File.open(csv_file.to_io), claims: submitted_claims)
+
+      submitted_claims.find_each do |claim|
+        claim.update!(status: :payment_in_progress, payment_in_progress_at: Time.current)
+      end
+
+      Claims::ClaimActivity.create!(action: :payment_delivered, user: current_user, record: payment)
+
+      transaction.after_commit do
+        Claims::PaymentMailer.payment_created_notification(payment).deliver_later
+      end
+    end
+  end
+
+  private
+
+  attr_reader :current_user
+
+  def submitted_claims
+    @submitted_claims ||= Claims::Claim.submitted
+  end
+end
diff --git a/app/services/claims/payments/claim/generate_csv_file.rb b/app/services/claims/payments/claim/generate_csv_file.rb
new file mode 100644
index 000000000..80931b2f7
--- /dev/null
+++ b/app/services/claims/payments/claim/generate_csv_file.rb
@@ -0,0 +1,50 @@
+require "csv"
+
+class Claims::Payments::Claim::GenerateCSVFile < ApplicationService
+  HEADERS = %w[
+    claim_reference
+    school_urn
+    school_name
+    school_local_authority
+    claim_amount
+    school_type_of_establishment
+    school_group
+    claim_submission_date
+    claim_status
+    claim_unpaid_reason
+  ].freeze
+
+  def initialize(claims:)
+    @claims = claims
+  end
+
+  def call
+    CSV.open(file_name, "w", headers: true) do |csv|
+      csv << HEADERS
+
+      claims.each do |claim|
+        csv << [
+          claim.reference,
+          claim.school.urn,
+          claim.school_name,
+          claim.school.local_authority_name,
+          claim.amount.format(symbol: false, decimal_mark: ".", no_cents: false),
+          claim.school.type_of_establishment,
+          claim.school.group,
+          claim.submitted_at&.iso8601,
+          claim.status,
+        ]
+      end
+
+      csv
+    end
+  end
+
+  private
+
+  attr_reader :claims
+
+  def file_name
+    Rails.root.join("tmp/payment-claims-#{Time.current}.csv")
+  end
+end
diff --git a/app/views/claims/payments/claims/error.html.erb b/app/views/claims/payments/claims/error.html.erb
new file mode 100644
index 000000000..446d1209f
--- /dev/null
+++ b/app/views/claims/payments/claims/error.html.erb
@@ -0,0 +1,11 @@
+<div class="govuk-width-container">
+  <div class="govuk-grid-row">
+    <div class="govuk-grid-column-two-thirds">
+      <h1 class="govuk-heading-l"><%= t(".page_title") %></h1>
+
+      <p class="govuk-body"><%= t(".description") %></p>
+
+      <p class="govuk-body"><%= t(".support_html", mail_to: govuk_mail_to(t("claims.support_email"), t("claims.support_email_html"))) %></p>
+    </div>
+  </div>
+</div>
diff --git a/app/views/claims/payments/claims/index.html.erb b/app/views/claims/payments/claims/index.html.erb
new file mode 100644
index 000000000..035244e16
--- /dev/null
+++ b/app/views/claims/payments/claims/index.html.erb
@@ -0,0 +1,13 @@
+<div class="govuk-width-container">
+  <div class="govuk-grid-row">
+    <div class="govuk-grid-column-two-thirds">
+      <h1 class="govuk-heading-l"><%= t(".page_title") %></h1>
+
+      <p class="govuk-body"><%= t(".description_html") %></p>
+
+      <p class="govuk-body"><%= t(".support_html", mail_to: govuk_mail_to(t("claims.support_email"), t("claims.support_email_html"))) %></p>
+
+      <%= govuk_button_link_to t(".submit"), download_claims_payments_claims_path(token: params[:token]) %>
+    </div>
+  </div>
+</div>
diff --git a/app/views/claims/support/claims/payments/index.html.erb b/app/views/claims/support/claims/payments/index.html.erb
index fc9d85b38..d20fa4780 100644
--- a/app/views/claims/support/claims/payments/index.html.erb
+++ b/app/views/claims/support/claims/payments/index.html.erb
@@ -8,6 +8,10 @@
 
   <h2 class="govuk-heading-m"><%= t(".sub_heading", count: @pagy.count) %></h2>
 
+  <div class="govuk-button-group">
+    <%= govuk_button_link_to t(".buttons.send_claims_to_esfa"), new_claims_support_claims_payment_path %>
+  </div>
+
   <% if @claims.any? %>
     <h3 class="govuk-heading-s"><%= t(".description", count: @pagy.count) %></h3>
 
diff --git a/app/views/claims/support/claims/payments/new.html.erb b/app/views/claims/support/claims/payments/new.html.erb
new file mode 100644
index 000000000..4463882ea
--- /dev/null
+++ b/app/views/claims/support/claims/payments/new.html.erb
@@ -0,0 +1,31 @@
+<%= render "claims/support/primary_navigation", current: :claims %>
+<% content_for(:page_title) { sanitize t(".page_title") } %>
+
+<% content_for(:before_content) do %>
+  <%= govuk_back_link href: claims_support_claims_payments_path %>
+<% end %>
+
+<div class="govuk-width-container">
+  <div class="govuk-grid-row">
+    <div class="govuk-grid-column-two-thirds">
+      <p class="govuk-caption-l"><%= t(".page_caption") %></p>
+      <h1 class="govuk-heading-l"><%= t(".page_title") %></h1>
+
+      <p class="govuk-body"><%= t(".description", count: @submitted_claims.count) %></p>
+
+      <p class="govuk-body"><%= t(".details.heading") %></p>
+
+      <%= govuk_list type: :bullet do %>
+        <% t(".details.list").each do |item| %>
+          <li><%= item %></li>
+        <% end %>
+      <% end %>
+
+      <%= govuk_warning_text text: t(".warning") %>
+
+      <%= govuk_button_to t(".submit"), claims_support_claims_payments_path %>
+
+      <p class="govuk-body"><%= govuk_link_to t(".cancel"), claims_support_claims_payments_path %></p>
+    </div>
+  </div>
+</div>
diff --git a/app/views/claims/support/claims/payments/new_not_permitted.html.erb b/app/views/claims/support/claims/payments/new_not_permitted.html.erb
new file mode 100644
index 000000000..4b7f5d5d0
--- /dev/null
+++ b/app/views/claims/support/claims/payments/new_not_permitted.html.erb
@@ -0,0 +1,19 @@
+<%= render "claims/support/primary_navigation", current: :claims %>
+<% content_for(:page_title) { sanitize t(".page_title") } %>
+
+<% content_for(:before_content) do %>
+  <%= govuk_back_link href: claims_support_claims_payments_path %>
+<% end %>
+
+<div class="govuk-width-container">
+  <div class="govuk-grid-row">
+    <div class="govuk-grid-column-two-thirds">
+      <p class="govuk-caption-l"><%= t(".page_caption") %></p>
+      <h1 class="govuk-heading-l"><%= t(".page_title") %></h1>
+
+      <p class="govuk-body"><%= t(".description") %></p>
+
+      <p class="govuk-body"><%= govuk_link_to t(".cancel"), claims_support_claims_payments_path %></p>
+    </div>
+  </div>
+</div>
diff --git a/config/application.rb b/config/application.rb
index d84457ce7..3c4c2a4c9 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -55,5 +55,11 @@ class Application < Rails::Application
 
     # Store user sessions in the database
     config.session_store :active_record_store
+
+    # Configure message verifiers to generate URL-safe tokens.
+    config.before_initialize do |app|
+      app.message_verifiers.clear_rotations
+      app.message_verifiers.rotate(url_safe: true)
+    end
   end
 end
diff --git a/config/locales/en/claims/payment_mailer.yml b/config/locales/en/claims/payment_mailer.yml
new file mode 100644
index 000000000..1caab91fb
--- /dev/null
+++ b/config/locales/en/claims/payment_mailer.yml
@@ -0,0 +1,30 @@
+en:
+  claims:
+    payment_mailer:
+      payment_created_notification:
+        subject: Claims ready for payment - Claim funding for mentor training
+        body: |
+          To ESFA,
+
+          These claims from the Claim funding for mentor training service (Claim) are ready for payment — the link to the latest CSV file is valid for 7 days:
+
+          [%{download_page_url}](%{download_page_url})
+
+          What you need to do:
+
+          1. Check and validate the claims in the CSV file by marking them as ‘paid’ or ‘unpaid’ in the ‘claim_status’ column.
+
+          2. If you mark a claim as ‘unpaid’, add the reason in the ‘claim_unpaid_reason’ column.
+
+          3. Reply to this email and attach the updated CSV file.
+
+          The Claim Support team will follow up on the reasons for unpaid claims and email back an updated version.
+
+          If you have a problem opening the link or it has expired, reply to this email and request that it be sent again.
+
+          # Give feedback or report a problem
+
+          If you have any questions or feedback, please contact the team at [%{support_email}](%{support_email}).
+
+          Regards
+          Claim funding for mentor training team
diff --git a/config/locales/en/claims/payments/claims.yml b/config/locales/en/claims/payments/claims.yml
new file mode 100644
index 000000000..c79f75f4f
--- /dev/null
+++ b/config/locales/en/claims/payments/claims.yml
@@ -0,0 +1,13 @@
+en:
+  claims:
+    payments:
+      claims:
+        index:
+          page_title: Download payments file
+          description_html: Download the Claim funding for mentor training payments <span title="Comma separated values">CSV</span> file.
+          support_html: If you have any questions, email %{mail_to}.
+          submit: Download CSV file
+        error:
+          page_title: Sorry, there is a problem with the download link
+          description: You are seeing this page because the download link is not working. It may have timed out or contained an invalid security token.
+          support_html: Email %{mail_to} to request a new download link.
diff --git a/config/locales/en/claims/support/claims/payments.yml b/config/locales/en/claims/support/claims/payments.yml
index 27076ae04..69a6bacca 100644
--- a/config/locales/en/claims/support/claims/payments.yml
+++ b/config/locales/en/claims/support/claims/payments.yml
@@ -9,7 +9,29 @@ en:
               zero: Payments
               one: Payments (%{count})
               other: Payments (%{count})
+            buttons:
+              send_claims_to_esfa: Send claims to ESFA
             description:
               one: "%{count} claim needs processing"
               other: "%{count} claims need processing"
             no_claims: There are no claims waiting to be processed.
+          new:
+            page_caption: Payments
+            page_title: Send claims to ESFA
+            description:
+              one: There is %{count} claim included in this submission.
+              other: There are %{count} claims included in this submission.
+            details:
+              heading: "Selecting ‘Send claims’ will:"
+              list:
+                - create a CSV containing a list of all ‘Submitted’ claims
+                - send an email to the ESFA containing a link to the generated CSV - this link expires after 7 days
+                - update the claim status from ‘Submitted’ to ‘Payment in progress’
+            warning: This action cannot be undone.
+            submit: Send claims
+            cancel: Cancel
+          new_not_permitted:
+            page_caption: Payments
+            page_title: There are no claims to send for payment
+            description: You cannot send any claims to the ESFA because there are no claims pending payment.
+            cancel: Cancel
diff --git a/config/routes/claims.rb b/config/routes/claims.rb
index e5a8c93b0..a5c0b7df4 100644
--- a/config/routes/claims.rb
+++ b/config/routes/claims.rb
@@ -13,6 +13,12 @@
 
   resources :service_updates, path: "service-updates", only: %i[index show]
 
+  namespace :payments do
+    resources :claims, only: %i[index] do
+      get :download, on: :collection
+    end
+  end
+
   resources :schools, only: %i[index show] do
     scope module: :schools do
       resources :claims do
@@ -76,12 +82,13 @@
         resources :claims, only: %i[show]
       end
 
-      resources :payments, only: %i[index]
+      resources :payments, only: %i[index new create]
       resources :samplings, path: "sampling/claims", only: %i[index show] do
         member do
           get :confirm_approval
           put :update
         end
+
         collection do
           get "new", to: "samplings/upload_data#new", as: :new_upload_data
           get "new/:state_key/:step", to: "samplings/upload_data#edit", as: :upload_data
diff --git a/spec/factories/claims/payments.rb b/spec/factories/claims/payments.rb
index 415809f44..b4e85bee7 100644
--- a/spec/factories/claims/payments.rb
+++ b/spec/factories/claims/payments.rb
@@ -18,5 +18,7 @@
 FactoryBot.define do
   factory :claims_payment, class: "Claims::Payment" do
     association :sent_by, factory: :claims_support_user
+
+    claims { build_list(:claim, 3, :submitted) }
   end
 end
diff --git a/spec/mailers/claims/payment_mailer_spec.rb b/spec/mailers/claims/payment_mailer_spec.rb
new file mode 100644
index 000000000..b32fe4ee0
--- /dev/null
+++ b/spec/mailers/claims/payment_mailer_spec.rb
@@ -0,0 +1,42 @@
+require "rails_helper"
+
+RSpec.describe Claims::PaymentMailer, freeze: "20 December 2024", type: :mailer do
+  describe "#payment_created_notification" do
+    subject(:email) { described_class.payment_created_notification(payment) }
+
+    let(:payment) { create(:claims_payment) }
+    let(:download_page_url) { claims_payments_claims_url(token:, host: "claims.localhost") }
+    let(:token) { Rails.application.message_verifier(:payments).generate(payment.id, expires_in: 7.days) }
+
+    it "sends the sampling checks required email" do
+      expect(email.to).to contain_exactly("esfa@example.com")
+      expect(email.subject).to eq("Claims ready for payment - Claim funding for mentor training")
+      expect(email.body.to_s.squish).to eq(<<~EMAIL.squish)
+        To ESFA,
+
+        These claims from the Claim funding for mentor training service (Claim) are ready for payment — the link to the latest CSV file is valid for 7 days:
+
+        [#{download_page_url}](#{download_page_url})
+
+        What you need to do:
+
+        1. Check and validate the claims in the CSV file by marking them as ‘paid’ or ‘unpaid’ in the ‘claim_status’ column.
+
+        2. If you mark a claim as ‘unpaid’, add the reason in the ‘claim_unpaid_reason’ column.
+
+        3. Reply to this email and attach the updated CSV file.
+
+        The Claim Support team will follow up on the reasons for unpaid claims and email back an updated version.
+
+        If you have a problem opening the link or it has expired, reply to this email and request that it be sent again.
+
+        # Give feedback or report a problem
+
+        If you have any questions or feedback, please contact the team at [ittmentor.funding@education.gov.uk](ittmentor.funding@education.gov.uk).
+
+        Regards
+        Claim funding for mentor training team
+      EMAIL
+    end
+  end
+end
diff --git a/spec/mailers/previews/claims/payment_mailer_preview.rb b/spec/mailers/previews/claims/payment_mailer_preview.rb
new file mode 100644
index 000000000..05bc2e54d
--- /dev/null
+++ b/spec/mailers/previews/claims/payment_mailer_preview.rb
@@ -0,0 +1,11 @@
+class Claims::PaymentMailerPreview < ActionMailer::Preview
+  def payment_created_notification
+    Claims::PaymentMailer.payment_created_notification(payment)
+  end
+
+  private
+
+  def payment
+    Claims::Payment.order(created_at: :desc).first_or_initialize(id: SecureRandom.uuid)
+  end
+end
diff --git a/spec/policies/claims/support/claims/payment_policy_spec.rb b/spec/policies/claims/support/claims/payment_policy_spec.rb
new file mode 100644
index 000000000..c593560f6
--- /dev/null
+++ b/spec/policies/claims/support/claims/payment_policy_spec.rb
@@ -0,0 +1,25 @@
+require "rails_helper"
+
+describe Claims::Support::Claims::PaymentPolicy do
+  subject { described_class }
+
+  let(:support_user) { build(:claims_support_user) }
+
+  permissions :new? do
+    it { is_expected.to permit(support_user, Claims::Payment) }
+  end
+
+  permissions :create? do
+    context "when there are submitted claims" do
+      before do
+        create(:claim, :submitted)
+      end
+
+      it { is_expected.to permit(support_user, Claims::Payment) }
+    end
+
+    context "when there are no submitted claims" do
+      it { is_expected.not_to permit(support_user, Claims::Payment) }
+    end
+  end
+end
diff --git a/spec/policies/claims/support/claims/payments/claim_policy_spec.rb b/spec/policies/claims/support/claims/payments/claim_policy_spec.rb
new file mode 100644
index 000000000..4de6f2a68
--- /dev/null
+++ b/spec/policies/claims/support/claims/payments/claim_policy_spec.rb
@@ -0,0 +1,16 @@
+require "rails_helper"
+
+describe Claims::Support::Claims::Payments::ClaimPolicy do
+  subject { described_class }
+
+  let(:support_user) { build(:claims_support_user) }
+  let(:claim) { build(:claim) }
+
+  permissions :show? do
+    it { is_expected.to permit(support_user, claim) }
+  end
+
+  permissions :edit?, :update? do
+    it { is_expected.not_to permit(support_user, claim) }
+  end
+end
diff --git a/spec/services/claims/payment/create_and_deliver_spec.rb b/spec/services/claims/payment/create_and_deliver_spec.rb
new file mode 100644
index 000000000..a88e76efb
--- /dev/null
+++ b/spec/services/claims/payment/create_and_deliver_spec.rb
@@ -0,0 +1,28 @@
+require "rails_helper"
+
+describe Claims::Payment::CreateAndDeliver do
+  subject(:create_and_deliver) { described_class.call(current_user:) }
+
+  let(:current_user) { create(:claims_support_user) }
+
+  describe "#call" do
+    it "does nothing when there are no submitted claims" do
+      expect { create_and_deliver }.to not_change(Claims::Payment, :count)
+        .and not_change(Claims::ClaimActivity, :count)
+        .and not_enqueue_mail(Claims::PaymentMailer, :payment_created_notification)
+    end
+
+    context "when there are submitted claims" do
+      before do
+        create(:claim, :submitted)
+      end
+
+      it "creates a payment, activity, updates claims statuses to 'payment_in_progress', and enqueues the deliver of an email to the ESFA" do
+        expect { create_and_deliver }.to change(Claims::Payment, :count).by(1)
+          .and change(Claims::ClaimActivity, :count).by(1)
+          .and change { Claims::Claim.pluck(:status).uniq }.from(%w[submitted]).to(%w[payment_in_progress])
+          .and enqueue_mail(Claims::PaymentMailer, :payment_created_notification)
+      end
+    end
+  end
+end
diff --git a/spec/services/claims/payments/claim/generate_csv_file_spec.rb b/spec/services/claims/payments/claim/generate_csv_file_spec.rb
new file mode 100644
index 000000000..ebd2b2cff
--- /dev/null
+++ b/spec/services/claims/payments/claim/generate_csv_file_spec.rb
@@ -0,0 +1,32 @@
+require "rails_helper"
+
+describe Claims::Payments::Claim::GenerateCSVFile do
+  subject(:generate_csv_file) { described_class.call(claims:) }
+
+  let(:claims) { create_list(:claim, 3) }
+
+  describe "#call" do
+    it "generates a CSV file of claims" do
+      expect(generate_csv_file).to be_a(CSV)
+      expect(generate_csv_file).to be_closed
+
+      csv = CSV.read(generate_csv_file.path)
+
+      expect(csv.first).to eq(%w[claim_reference school_urn school_name school_local_authority claim_amount school_type_of_establishment school_group claim_submission_date claim_status claim_unpaid_reason])
+
+      claims.each_with_index do |claim, index|
+        expect(csv[index + 1]).to eq([
+          claim.reference,
+          claim.school.urn,
+          claim.school_name,
+          claim.school.local_authority_name,
+          claim.amount.format(symbol: false, decimal_mark: ".", no_cents: false),
+          claim.school.type_of_establishment,
+          claim.school.group,
+          claim.submitted_at&.iso8601,
+          claim.status,
+        ])
+      end
+    end
+  end
+end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index f4a34c4b6..2bfd1c737 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -45,6 +45,7 @@
 # Instead, define negated versions of whatever matchers you wish to negate with
 # `RSpec::Matchers.define_negated_matcher` and use `expect(...).to matcher.and matcher`.
 RSpec::Matchers.define_negated_matcher :not_change, :change
+RSpec::Matchers.define_negated_matcher :not_enqueue_mail, :enqueue_mail
 RSpec::Matchers.define_negated_matcher :not_have_enqueued_mail, :have_enqueued_mail
 RSpec::Matchers.define_negated_matcher :not_have_enqueued_job, :have_enqueued_job
 
diff --git a/spec/system/claims/payments/claims/download_claims_spec.rb b/spec/system/claims/payments/claims/download_claims_spec.rb
new file mode 100644
index 000000000..3f5b25690
--- /dev/null
+++ b/spec/system/claims/payments/claims/download_claims_spec.rb
@@ -0,0 +1,62 @@
+require "rails_helper"
+
+RSpec.describe "Download payment claims", service: :claims, type: :system do
+  let(:payment) { create(:claims_payment) }
+
+  let(:valid_token) { Rails.application.message_verifier(:payments).generate(payment.id, expires_in: 7.days) }
+  let(:invalid_token) { Rails.application.message_verifier(:payments).generate("invalid_id", expires_in: 7.days) }
+  let(:expired_token) { Rails.application.message_verifier(:payments).generate(payment.id, expires_at: 10.days.ago) }
+  let(:random_token) { "random" }
+
+  scenario "ESFA user clicks on a valid link in their email inbox" do
+    when_i_visit_the_download_url(token: valid_token)
+    then_i_see_a_page_with_download_button
+
+    when_i_click_on_the_download_button
+    then_a_csv_file_is_downloaded
+  end
+
+  scenario "ESFA user clicks on an expired link in their email inbox" do
+    when_i_visit_the_download_url(token: expired_token)
+    then_i_see_an_error_page
+  end
+
+  scenario "ESFA user visits the url with an invalid token" do
+    when_i_visit_the_download_url(token: invalid_token)
+    then_i_see_an_error_page
+  end
+
+  scenario "ESFA user visits the url with a random token" do
+    when_i_visit_the_download_url(token: random_token)
+    then_i_see_an_error_page
+  end
+
+  scenario "ESFA user visits the url without a token" do
+    when_i_visit_the_download_url(token: nil)
+    then_i_see_an_error_page
+  end
+
+  private
+
+  def when_i_visit_the_download_url(token:)
+    visit claims_payments_claims_path(token:)
+  end
+
+  def then_i_see_a_page_with_download_button
+    expect(page).to have_css("h1.govuk-heading-l", text: "Download payments file")
+  end
+
+  def then_i_see_an_error_page
+    expect(page).to have_css("h1.govuk-heading-l", text: "Sorry, there is a problem with the download link")
+    expect(page).to have_css("p.govuk-body", text: "You are seeing this page because the download link is not working. It may have timed out or contained an invalid security token.")
+    expect(page).to have_css("p.govuk-body", text: "Email ittmentor.funding@education.gov.uk to request a new download link.")
+  end
+
+  def when_i_click_on_the_download_button
+    click_on "Download CSV file"
+  end
+
+  def then_a_csv_file_is_downloaded
+    expect(response_headers["Content-Type"]).to eq "text/csv"
+  end
+end
diff --git a/spec/system/claims/support/claims/payments/send_claims_to_esfa_spec.rb b/spec/system/claims/support/claims/payments/send_claims_to_esfa_spec.rb
new file mode 100644
index 000000000..8d6b88d09
--- /dev/null
+++ b/spec/system/claims/support/claims/payments/send_claims_to_esfa_spec.rb
@@ -0,0 +1,80 @@
+require "rails_helper"
+
+RSpec.describe "Send claims to ESFA", service: :claims, type: :system do
+  let(:support_user) { create(:claims_support_user) }
+
+  before do
+    user_exists_in_dfe_sign_in(user: support_user)
+  end
+
+  scenario "Support user attempts to send claims to ESFA, but there are no 'submitted' claims" do
+    given_i_sign_in
+    when_i_visit_claims_payments_index_page
+    when_i_click_on_send_claims_to_esfa
+    then_i_can_see_an_error_page
+  end
+
+  context "when there are submitted claims" do
+    before do
+      create_list(:claim, 3, :submitted)
+    end
+
+    scenario "Support user sends claims to ESFA" do
+      given_i_sign_in
+      when_i_visit_claims_payments_index_page
+      when_i_click_on_send_claims_to_esfa
+      then_i_can_see_a_confirmation_page
+
+      when_i_click_on_send_claims
+      then_i_see_a_success_flash_message
+      and_claims_have_been_sent_to_esfa
+    end
+  end
+
+  private
+
+  def given_i_sign_in
+    visit sign_in_path
+    click_on "Sign in using DfE Sign In"
+  end
+
+  def when_i_visit_claims_payments_index_page
+    click_on("Claims")
+    click_on("Payments")
+  end
+
+  def when_i_click_on_send_claims_to_esfa
+    click_on("Send claims to ESFA")
+  end
+
+  def then_i_can_see_an_error_page
+    expect(page).to have_css("p.govuk-caption-l", text: "Payments")
+    expect(page).to have_css("h1.govuk-heading-l", text: "There are no claims to send for payment")
+    expect(page).to have_css("p.govuk-body", text: "You cannot send any claims to the ESFA because there are no claims pending payment.")
+    expect(page).to have_link("Cancel", href: claims_support_claims_payments_path)
+  end
+
+  def then_i_can_see_a_confirmation_page
+    expect(page).to have_css("p.govuk-caption-l", text: "Payments")
+    expect(page).to have_css("h1.govuk-heading-l", text: "Send claims to ESFA")
+    expect(page).to have_css("p.govuk-body", text: "There are 3 claims included in this submission.")
+    expect(page).to have_css("p.govuk-body", text: "Selecting ‘Send claims’ will:")
+    expect(page).to have_css("li", text: "create a CSV containing a list of all ‘Submitted’ claims")
+    expect(page).to have_css("li", text: "send an email to the ESFA containing a link to the generated CSV - this link expires after 7 days")
+    expect(page).to have_css("li", text: "update the claim status from ‘Submitted’ to ‘Payment in progress’")
+    expect(page).to have_css("div.govuk-warning-text", text: "This action cannot be undone.")
+  end
+
+  def when_i_click_on_send_claims
+    click_on("Send claims")
+  end
+
+  def then_i_see_a_success_flash_message
+    expect(page).to have_content("Claims sent to ESFA")
+  end
+
+  def and_claims_have_been_sent_to_esfa
+    expect(Claims::Claim.submitted.count).to eq(0)
+    expect(Claims::Claim.payment_in_progress.count).to eq(3)
+  end
+end