diff --git a/src/amplitude-client.js b/src/amplitude-client.js
index cafdc344..325dfe61 100644
--- a/src/amplitude-client.js
+++ b/src/amplitude-client.js
@@ -1407,6 +1407,7 @@ AmplitudeClient.prototype._logEvent = function _logEvent(
       groups: utils.truncate(utils.validateGroups(groups)),
       group_properties: utils.truncate(utils.validateProperties(groupProperties)),
       user_agent: this._userAgent,
+      partner_id: this.options.partnerId || null,
     };
 
     if (_isObservePlanSet(this)) {
diff --git a/src/options.js b/src/options.js
index 9c0887f5..e582a846 100644
--- a/src/options.js
+++ b/src/options.js
@@ -54,6 +54,7 @@ import { version as libraryVersion } from '../package.json';
  * @property {boolean} [useDynamicConfig] - Enable dynamic configuration to find best server url for user.
  * @property {boolean} [serverZoneBasedApi] - To update api endpoint with serverZone change or not. For data residency, recommend to enable it unless using own proxy server.
  * @property {number} [sessionId=`null`] - The custom Session ID for the current session. *Note: This is not recommended unless you know what you are doing because the Session ID of a session is utilized for all session metrics in Amplitude.
+ * @property {string} [partnerId=`null`] - The partner id value
  */
 export default {
   apiEndpoint: Constants.EVENT_LOG_URL,
@@ -125,4 +126,5 @@ export default {
   useDynamicConfig: false,
   serverZoneBasedApi: false,
   sessionId: null,
+  partnerId: '',
 };
diff --git a/test/amplitude-client.js b/test/amplitude-client.js
index 5198f5ef..3ffe552f 100644
--- a/test/amplitude-client.js
+++ b/test/amplitude-client.js
@@ -4551,4 +4551,25 @@ describe('AmplitudeClient', function () {
       requestStub.restore();
     });
   });
+
+  describe('partnerId Support', function () {
+    beforeEach(function () {
+      reset();
+    });
+
+    it('should include partner_id', function () {
+      const partnerId = 'test-partner-id';
+      amplitude.init(apiKey, null, { batchEvents: true, partnerId: partnerId });
+
+      amplitude.logEvent('testEvent1');
+      assert.equal(amplitude._unsentEvents[0].event.partner_id, partnerId);
+    });
+
+    it('should set partner_id default null', function () {
+      amplitude.init(apiKey, null, { batchEvents: true });
+
+      amplitude.logEvent('testEvent1');
+      assert.equal(amplitude._unsentEvents[0].event.partner_id, null);
+    });
+  });
 });