diff --git a/spec/src/modules/tracker.js b/spec/src/modules/tracker.js
index 6147c992..94d545cf 100644
--- a/spec/src/modules/tracker.js
+++ b/spec/src/modules/tracker.js
@@ -16345,4 +16345,39 @@ describe(`ConstructorIO - Tracker${bundledDescriptionSuffix}`, () => {
       ).to.equal(true);
     });
   });
+
+  describe('additionalTrackingKeys', () => {
+    it('Should send tracking events to both primary and additional keys', (done) => {
+      const additionalKey = 'extra-test-key';
+      const { tracker } = new ConstructorIO({
+        apiKey: testApiKey,
+        fetch: fetchSpy,
+        ...requestQueueOptions,
+        additionalTrackingKeys: [additionalKey],
+      });
+
+      let callCount = 0;
+
+      const checkComplete = () => {
+        callCount += 1;
+
+        if (callCount === 2) {
+          expect(fetchSpy).to.have.been.calledTwice;
+
+          const firstCallUrl = fetchSpy.getCall(0).args[0];
+          const secondCallUrl = fetchSpy.getCall(1).args[0];
+
+          expect(firstCallUrl).to.contain(`key=${testApiKey}`);
+          expect(secondCallUrl).to.contain(`key=${additionalKey}`);
+
+          done();
+        }
+      };
+
+      tracker.on('success', checkComplete);
+      tracker.on('error', checkComplete);
+
+      expect(tracker.trackSessionStartV2()).to.equal(true);
+    });
+  });
 });
diff --git a/spec/src/utils/request-queue.js b/spec/src/utils/request-queue.js
index 767e5bed..60824589 100644
--- a/spec/src/utils/request-queue.js
+++ b/spec/src/utils/request-queue.js
@@ -318,6 +318,121 @@ describe('ConstructorIO - Utils - Request Queue', function utilsRequestQueue() {
       });
     });
 
+    describe('additionalTrackingKeys', () => {
+      let defaultAgent;
+      let cleanup;
+
+      before(() => {
+        helpers.clearStorage();
+      });
+
+      beforeEach(() => {
+        global.CLIENT_VERSION = 'cio-mocha';
+        cleanup = jsdom();
+        defaultAgent = window.navigator.userAgent;
+      });
+
+      afterEach(() => {
+        window.navigator.__defineGetter__('userAgent', () => defaultAgent);
+        delete global.CLIENT_VERSION;
+        cleanup();
+        helpers.clearStorage();
+      });
+
+      it('Should add duplicate requests for each additional tracking key', () => {
+        store.session.set(humanityStorageKey, true);
+        const requests = new RequestQueue({
+          sendTrackingEvents: true,
+          trackingSendDelay: 1,
+          apiKey: 'primary-key',
+          additionalTrackingKeys: ['extra-key-1', 'extra-key-2'],
+        });
+
+        requests.queue('https://ac.cnstrc.com/behavior?action=session_start&key=primary-key&_dt=123', 'POST', { action: 'session_start', key: 'primary-key' });
+
+        const queue = RequestQueue.get();
+        expect(queue).to.be.an('array').length(3);
+
+        // Primary request
+        expect(queue[0].url).to.contain('key=primary-key');
+        expect(queue[0].body.key).to.equal('primary-key');
+
+        // First additional key
+        expect(queue[1].url).to.contain('key=extra-key-1');
+        expect(queue[1].url).to.not.contain('key=primary-key');
+        expect(queue[1].body.key).to.equal('extra-key-1');
+
+        // Second additional key
+        expect(queue[2].url).to.contain('key=extra-key-2');
+        expect(queue[2].url).to.not.contain('key=primary-key');
+        expect(queue[2].body.key).to.equal('extra-key-2');
+      });
+
+      it('Should not add duplicates when additionalTrackingKeys is an empty array', () => {
+        store.session.set(humanityStorageKey, true);
+        const requests = new RequestQueue({
+          sendTrackingEvents: true,
+          trackingSendDelay: 1,
+          apiKey: 'primary-key',
+          additionalTrackingKeys: [],
+        });
+
+        requests.queue('https://ac.cnstrc.com/behavior?action=session_start&key=primary-key&_dt=123');
+
+        expect(RequestQueue.get()).to.be.an('array').length(1);
+      });
+
+      it('Should not add duplicates when additionalTrackingKeys is not provided', () => {
+        store.session.set(humanityStorageKey, true);
+        const requests = new RequestQueue({
+          sendTrackingEvents: true,
+          trackingSendDelay: 1,
+          apiKey: 'primary-key',
+        });
+
+        requests.queue('https://ac.cnstrc.com/behavior?action=session_start&key=primary-key&_dt=123');
+
+        expect(RequestQueue.get()).to.be.an('array').length(1);
+      });
+
+      it('Should add duplicate requests for GET method', () => {
+        store.session.set(humanityStorageKey, true);
+        const requests = new RequestQueue({
+          sendTrackingEvents: true,
+          trackingSendDelay: 1,
+          apiKey: 'primary-key',
+          additionalTrackingKeys: ['extra-key-1'],
+        });
+
+        requests.queue('https://ac.cnstrc.com/behavior?action=session_start&key=primary-key&_dt=123');
+
+        const queue = RequestQueue.get();
+        expect(queue).to.be.an('array').length(2);
+
+        expect(queue[0].url).to.contain('key=primary-key');
+        expect(queue[1].url).to.contain('key=extra-key-1');
+        expect(queue[1].url).to.contain('action=session_start');
+        expect(queue[1].body.key).to.equal('extra-key-1');
+      });
+
+      it('Should skip invalid entries in additionalTrackingKeys', () => {
+        store.session.set(humanityStorageKey, true);
+        const requests = new RequestQueue({
+          sendTrackingEvents: true,
+          trackingSendDelay: 1,
+          apiKey: 'primary-key',
+          additionalTrackingKeys: ['valid-key', '', null, 123, 'another-valid-key'],
+        });
+
+        requests.queue('https://ac.cnstrc.com/behavior?action=session_start&key=primary-key&_dt=123', 'POST', { action: 'session_start', key: 'primary-key' });
+
+        const queue = RequestQueue.get();
+        expect(queue).to.be.an('array').length(3);
+        expect(queue[1].url).to.contain('key=valid-key');
+        expect(queue[2].url).to.contain('key=another-valid-key');
+      });
+    });
+
     describe('send', () => {
       let fetchSpy = null;
       let cleanup;
diff --git a/src/constructorio.js b/src/constructorio.js
index b0691dd3..ea8c2ec9 100644
--- a/src/constructorio.js
+++ b/src/constructorio.js
@@ -59,6 +59,7 @@ class ConstructorIO {
    * @param {object} [parameters.networkParameters] - Parameters relevant to network requests
    * @param {number} [parameters.networkParameters.timeout] - Request timeout (in milliseconds) - may be overridden within individual method calls
    * @param {string} [parameters.humanityCheckLocation='session'] - Storage location for the humanity check flag ('session' for sessionStorage, 'local' for localStorage)
+   * @param {string[]} [parameters.additionalTrackingKeys] - Additional API keys to duplicate tracking events to
    * @property {object} search - Interface to {@link module:search}
    * @property {object} browse - Interface to {@link module:browse}
    * @property {object} autocomplete - Interface to {@link module:autocomplete}
@@ -93,6 +94,7 @@ class ConstructorIO {
       beaconMode,
       networkParameters,
       humanityCheckLocation,
+      additionalTrackingKeys,
     } = options;
 
     if (!apiKey || typeof apiKey !== 'string') {
@@ -141,6 +143,7 @@ class ConstructorIO {
       beaconMode: (beaconMode === false) ? false : true, // Defaults to 'true',
       networkParameters: networkParameters || {},
       humanityCheckLocation: humanityCheckLocation || 'session',
+      additionalTrackingKeys,
     };
 
     // Expose global modules
diff --git a/src/types/index.d.ts b/src/types/index.d.ts
index bd093e43..15b3ba1e 100644
--- a/src/types/index.d.ts
+++ b/src/types/index.d.ts
@@ -71,6 +71,7 @@ export interface ConstructorClientOptions {
   beaconMode?: boolean;
   networkParameters?: NetworkParameters;
   humanityCheckLocation?: 'session' | 'local';
+  additionalTrackingKeys?: string[];
 }
 
 export interface RequestFeature extends Record<string, any> {
diff --git a/src/utils/request-queue.js b/src/utils/request-queue.js
index 291d0724..d398c85b 100644
--- a/src/utils/request-queue.js
+++ b/src/utils/request-queue.js
@@ -53,6 +53,28 @@ class RequestQueue {
         body,
         networkParameters,
       });
+
+      // Duplicate request for each additional tracking key
+      const additionalKeys = this.options?.additionalTrackingKeys;
+
+      if (Array.isArray(additionalKeys) && additionalKeys.length) {
+        const encodedOriginalKey = helpers.encodeURIComponentRFC3986(this.options.apiKey);
+
+        const validKeys = additionalKeys.filter((key) => key && typeof key === 'string');
+
+        validKeys.forEach((additionalKey) => {
+          const encodedKey = helpers.encodeURIComponentRFC3986(additionalKey);
+          const swappedUrl = url.replace(`key=${encodedOriginalKey}`, `key=${encodedKey}`);
+
+          queue.push({
+            url: obfuscatePiiRequest(swappedUrl),
+            method,
+            body: { ...body, key: additionalKey },
+            networkParameters,
+          });
+        });
+      }
+
       RequestQueue.set(queue);
     }
   }