diff --git a/modules/33acrossBidAdapter.js b/modules/33acrossBidAdapter.js
index 26fc0a11fd5..bdc80ade375 100644
--- a/modules/33acrossBidAdapter.js
+++ b/modules/33acrossBidAdapter.js
@@ -251,6 +251,7 @@ function _createServerRequest({ bidRequests, gdprConsent = {}, uspConsent, pageU
   const ttxRequest = {};
   const firstBidRequest = bidRequests[0];
   const { siteId, test } = firstBidRequest.params;
+  const coppaValue = config.getConfig('coppa');
 
   /*
    * Infer data for the request payload
@@ -296,6 +297,10 @@ function _createServerRequest({ bidRequests, gdprConsent = {}, uspConsent, pageU
     });
   }
 
+  if (coppaValue !== undefined) {
+    ttxRequest.regs.coppa = Number(!!coppaValue);
+  }
+
   ttxRequest.ext = {
     ttx: {
       prebidStartedAt: Date.now(),
diff --git a/modules/33acrossIdSystem.js b/modules/33acrossIdSystem.js
index be81b26b110..802c2651d29 100644
--- a/modules/33acrossIdSystem.js
+++ b/modules/33acrossIdSystem.js
@@ -8,7 +8,7 @@
 import { logMessage, logError } from '../src/utils.js';
 import { ajaxBuilder } from '../src/ajax.js';
 import { submodule } from '../src/hook.js';
-import { uspDataHandler } from '../src/adapterManager.js';
+import { uspDataHandler, coppaDataHandler } from '../src/adapterManager.js';
 
 const MODULE_NAME = '33acrossId';
 const API_URL = 'https://lexicon.33across.com/v1/envelope';
@@ -37,11 +37,13 @@ function getEnvelope(response) {
 function calculateQueryStringParams(pid, gdprConsentData) {
   const uspString = uspDataHandler.getConsentData();
   const gdprApplies = Boolean(gdprConsentData?.gdprApplies);
+  const coppaValue = coppaDataHandler.getCoppa();
   const params = {
     pid,
     gdpr: Number(gdprApplies),
     src: CALLER_NAME,
-    ver: '$prebid.version$'
+    ver: '$prebid.version$',
+    coppa: Number(coppaValue)
   };
 
   if (uspString) {
diff --git a/test/spec/modules/33acrossBidAdapter_spec.js b/test/spec/modules/33acrossBidAdapter_spec.js
index aa2621f1fa0..d0b590336b9 100644
--- a/test/spec/modules/33acrossBidAdapter_spec.js
+++ b/test/spec/modules/33acrossBidAdapter_spec.js
@@ -200,6 +200,14 @@ describe('33acrossBidAdapter:', function () {
       return this;
     };
 
+    this.withCoppa = coppaValue => {
+      Object.assign(ttxRequest.regs, {
+        coppa: coppaValue
+      });
+
+      return this;
+    };
+
     this.withSite = site => {
       Object.assign(ttxRequest, { site });
       return this;
@@ -1059,6 +1067,7 @@ describe('33acrossBidAdapter:', function () {
           .withBanner()
           .withProduct()
           .withGdprConsent('foobarMyPreference', 1)
+          .withCoppa(1)
           .build();
         const serverRequest = new ServerRequestBuilder()
           .withData(ttxRequest)
@@ -1094,6 +1103,7 @@ describe('33acrossBidAdapter:', function () {
         const ttxRequest = new TtxRequestBuilder()
           .withBanner()
           .withProduct()
+          .withCoppa(1)
           .build();
         const serverRequest = new ServerRequestBuilder()
           .withData(ttxRequest)
@@ -1138,6 +1148,7 @@ describe('33acrossBidAdapter:', function () {
           .withBanner()
           .withProduct()
           .withUspConsent('foo')
+          .withCoppa(1)
           .build();
         const serverRequest = new ServerRequestBuilder()
           .withData(ttxRequest)
@@ -1173,6 +1184,7 @@ describe('33acrossBidAdapter:', function () {
         const ttxRequest = new TtxRequestBuilder()
           .withBanner()
           .withProduct()
+          .withCoppa(1)
           .build();
         const serverRequest = new ServerRequestBuilder()
           .withData(ttxRequest)
@@ -1184,6 +1196,42 @@ describe('33acrossBidAdapter:', function () {
       });
     });
 
+    context('when coppa is enabled', function() {
+      it('returns corresponding server requests with coppa: 1', function() {
+        sandbox.stub(config, 'getConfig').withArgs('coppa').returns(true);
+
+        const ttxRequest = new TtxRequestBuilder()
+          .withBanner()
+          .withProduct()
+          .withCoppa(1)
+          .build();
+        const serverRequest = new ServerRequestBuilder()
+          .withData(ttxRequest)
+          .build();
+        const [ builtServerRequest ] = spec.buildRequests(bidRequests, bidderRequest);
+
+        validateBuiltServerRequest(builtServerRequest, serverRequest);
+      });
+    });
+
+    context('when coppa is not enabled', function() {
+      it('returns corresponding server requests with coppa: 0', function() {
+        sandbox.stub(config, 'getConfig').withArgs('coppa').returns(false);
+
+        const ttxRequest = new TtxRequestBuilder()
+          .withBanner()
+          .withProduct()
+          .withCoppa(0)
+          .build();
+        const serverRequest = new ServerRequestBuilder()
+          .withData(ttxRequest)
+          .build();
+        const [ builtServerRequest ] = spec.buildRequests(bidRequests, bidderRequest);
+
+        validateBuiltServerRequest(builtServerRequest, serverRequest);
+      });
+    });
+
     context('when refererInfo values are available', function() {
       context('when refererInfo.page is defined', function() {
         it('returns corresponding server requests with site.page set', function() {
@@ -1780,12 +1828,14 @@ describe('33acrossBidAdapter:', function () {
           .withProduct('siab')
           .withBanner()
           .withVideo()
+          .withCoppa(1)
           .build();
 
         const req2 = new TtxRequestBuilder('sample33xGUID123456780')
           .withProduct('siab')
           .withBanner()
           .withVideo()
+          .withCoppa(1)
           .build();
 
         req2.imp[0].id = 'b3';
@@ -1794,6 +1844,7 @@ describe('33acrossBidAdapter:', function () {
           .withProduct('inview')
           .withBanner()
           .withVideo()
+          .withCoppa(1)
           .build();
 
         req3.imp[0].id = 'b4';
diff --git a/test/spec/modules/33acrossIdSystem_spec.js b/test/spec/modules/33acrossIdSystem_spec.js
index 5070d2b8845..e41d6d90d81 100644
--- a/test/spec/modules/33acrossIdSystem_spec.js
+++ b/test/spec/modules/33acrossIdSystem_spec.js
@@ -2,7 +2,7 @@ import { thirthyThreeAcrossIdSubmodule } from 'modules/33acrossIdSystem.js';
 import * as utils from 'src/utils.js';
 
 import { server } from 'test/mocks/xhr.js';
-import { uspDataHandler } from 'src/adapterManager.js';
+import { uspDataHandler, coppaDataHandler } from 'src/adapterManager.js';
 
 describe('33acrossIdSystem', () => {
   describe('name', () => {
@@ -157,6 +157,48 @@ describe('33acrossIdSystem', () => {
       });
     });
 
+    context('when coppa is enabled', () => {
+      it('should call endpoint with an enabled coppa signal', () => {
+        const completeCallback = () => {};
+        const { callback } = thirthyThreeAcrossIdSubmodule.getId({
+          params: {
+            pid: '12345'
+          }
+        });
+
+        sinon.stub(coppaDataHandler, 'getCoppa').returns(true);
+
+        callback(completeCallback);
+
+        const [request] = server.requests;
+
+        expect(request.url).to.contain('coppa=1');
+
+        coppaDataHandler.getCoppa.restore();
+      });
+    });
+
+    context('when coppa is not enabled', () => {
+      it('should call endpoint with coppa signal not enabled', () => {
+        const completeCallback = () => {};
+        const { callback } = thirthyThreeAcrossIdSubmodule.getId({
+          params: {
+            pid: '12345'
+          }
+        });
+
+        sinon.stub(coppaDataHandler, 'getCoppa').returns(false);
+
+        callback(completeCallback);
+
+        const [request] = server.requests;
+
+        expect(request.url).to.contain('coppa=0');
+
+        coppaDataHandler.getCoppa.restore();
+      });
+    });
+
     context('when the partner ID is not given', () => {
       it('should log an error', () => {
         const logErrorSpy = sinon.spy(utils, 'logError');