diff --git a/modules/connatixBidAdapter.js b/modules/connatixBidAdapter.js
index 802ad855e27..e2cba7d2dee 100644
--- a/modules/connatixBidAdapter.js
+++ b/modules/connatixBidAdapter.js
@@ -7,7 +7,8 @@ import {
   isFn,
   logError,
   isArray,
-  formatQS
+  formatQS,
+  deepSetValue
 } from '../src/utils.js';
 
 import {
@@ -61,6 +62,16 @@ export function validateVideo(mediaTypes) {
   return video.context !== ADPOD;
 }
 
+/**
+ * Get ids from Prebid User ID Modules and add them to the payload
+ */
+function _handleEids(payload, validBidRequests) {
+  let bidUserIdAsEids = deepAccess(validBidRequests, '0.userIdAsEids');
+  if (isArray(bidUserIdAsEids) && bidUserIdAsEids.length > 0) {
+    deepSetValue(payload, 'userIdList', bidUserIdAsEids);
+  }
+}
+
 export const spec = {
   code: BIDDER_CODE,
   gvlid: 143,
@@ -130,6 +141,8 @@ export const spec = {
       bidRequests,
     };
 
+    _handleEids(requestPayload, validBidRequests);
+
     return {
       method: 'POST',
       url: AD_URL,
diff --git a/test/spec/modules/connatixBidAdapter_spec.js b/test/spec/modules/connatixBidAdapter_spec.js
index 1bf04ed9db8..9b3eb4709c0 100644
--- a/test/spec/modules/connatixBidAdapter_spec.js
+++ b/test/spec/modules/connatixBidAdapter_spec.js
@@ -356,6 +356,38 @@ describe('connatixBidAdapter', function () {
     });
   });
 
+  describe('userIdAsEids', function() {
+    let validBidRequests;
+
+    this.beforeEach(function () {
+      bid = mockBidRequest();
+      validBidRequests = [bid];
+    })
+
+    it('Connatix adapter reads EIDs from Prebid user models and adds it to Request', function() {
+      validBidRequests[0].userIdAsEids = [{
+        'source': 'adserver.org',
+        'uids': [{
+          'id': 'TTD_ID_FROM_USER_ID_MODULE',
+          'atype': 1,
+          'ext': {
+            'stype': 'ppuid',
+            'rtiPartner': 'TDID'
+          }
+        }]
+      },
+      {
+        'source': 'pubserver.org',
+        'uids': [{
+          'id': 'TDID_FROM_USER_ID_MODULE',
+          'atype': 1
+        }]
+      }];
+      let serverRequest = spec.buildRequests(validBidRequests, {});
+      expect(serverRequest.data.userIdList).to.deep.equal(validBidRequests[0].userIdAsEids);
+    });
+  });
+
   describe('getBidFloor', function () {
     this.beforeEach(function () {
       bid = mockBidRequest();