diff --git a/modules/ixBidAdapter.js b/modules/ixBidAdapter.js
index 3146223f23c..bcdffa12e86 100644
--- a/modules/ixBidAdapter.js
+++ b/modules/ixBidAdapter.js
@@ -76,7 +76,8 @@ const SOURCE_RTI_MAPPING = {
   'audigent.com': '', // Hadron ID from Audigent, hadronId
   'pubcid.org': '', // SharedID, pubcid
   'utiq.com': '', // Utiq
-  'intimatemerger.com': ''
+  'intimatemerger.com': '',
+  '33across.com': ''
 };
 const PROVIDERS = [
   'britepoolid',
diff --git a/test/spec/modules/ixBidAdapter_spec.js b/test/spec/modules/ixBidAdapter_spec.js
index 2097354035e..6b166b05803 100644
--- a/test/spec/modules/ixBidAdapter_spec.js
+++ b/test/spec/modules/ixBidAdapter_spec.js
@@ -759,7 +759,8 @@ describe('IndexexchangeAdapter', function () {
     uid2: { id: 'testuid2' }, // UID 2.0
     // similar to uid2, but id5's getValue takes .uid
     id5id: { uid: 'testid5id' }, // ID5
-    imuid: 'testimuid'
+    imuid: 'testimuid',
+    '33acrossId': { envelope: 'v1.5fs.1000.fjdiosmclds' }
   };
 
   const DEFAULT_USERIDASEIDS_DATA = createEidsArray(DEFAULT_USERID_DATA);
@@ -813,7 +814,12 @@ describe('IndexexchangeAdapter', function () {
     }, {
       source: 'intimatemerger.com',
       uids: [{
-        id: DEFAULT_USERID_DATA.imuid,
+        id: DEFAULT_USERID_DATA.imuid
+      }]
+    }, {
+      source: '33across.com',
+      uids: [{
+        id: DEFAULT_USERID_DATA['33acrossId'].envelope
       }]
     }
   ];
@@ -1219,7 +1225,7 @@ describe('IndexexchangeAdapter', function () {
         const payload = extractPayload(request[0]);
         expect(request).to.be.an('array');
         expect(request).to.have.lengthOf.above(0); // should be 1 or more
-        expect(payload.user.eids).to.have.lengthOf(7);
+        expect(payload.user.eids).to.have.lengthOf(8);
         expect(payload.user.eids).to.deep.include(DEFAULT_USERID_PAYLOAD[0]);
       });
     });
@@ -1407,7 +1413,7 @@ describe('IndexexchangeAdapter', function () {
       cloneValidBid[0].userIdAsEids = utils.deepClone(DEFAULT_USERIDASEIDS_DATA);
       const request = spec.buildRequests(cloneValidBid, DEFAULT_OPTION)[0];
       const payload = extractPayload(request);
-      expect(payload.user.eids).to.have.lengthOf(7);
+      expect(payload.user.eids).to.have.lengthOf(8);
       expect(payload.user.eids).to.have.deep.members(DEFAULT_USERID_PAYLOAD);
     });
 
@@ -1540,7 +1546,7 @@ describe('IndexexchangeAdapter', function () {
       })
 
       expect(payload.user).to.exist;
-      expect(payload.user.eids).to.have.lengthOf(9);
+      expect(payload.user.eids).to.have.lengthOf(10);
 
       expect(payload.user.eids).to.have.deep.members(validUserIdPayload);
     });
@@ -1582,7 +1588,7 @@ describe('IndexexchangeAdapter', function () {
       });
 
       const payload = extractPayload(request);
-      expect(payload.user.eids).to.have.lengthOf(8);
+      expect(payload.user.eids).to.have.lengthOf(9);
       expect(payload.user.eids).to.have.deep.members(validUserIdPayload);
     });
   });