diff --git a/packages/remote-feature-flag-controller/src/remote-feature-flag-controller.test.ts b/packages/remote-feature-flag-controller/src/remote-feature-flag-controller.test.ts
index 7ec1cfb76a..511ea6f222 100644
--- a/packages/remote-feature-flag-controller/src/remote-feature-flag-controller.test.ts
+++ b/packages/remote-feature-flag-controller/src/remote-feature-flag-controller.test.ts
@@ -59,7 +59,7 @@ function createController(
     state: Partial<RemoteFeatureFlagControllerState>;
     clientConfigApiService: AbstractClientConfigApiService;
     disabled: boolean;
-    getMetaMetricsId: () => Promise<string> | string;
+    getMetaMetricsId: () => string;
   }> = {},
 ) {
   return new RemoteFeatureFlagController({
@@ -69,7 +69,7 @@ function createController(
       options.clientConfigApiService ?? buildClientConfigApiService(),
     disabled: options.disabled,
     getMetaMetricsId:
-      options.getMetaMetricsId ?? (() => Promise.resolve(MOCK_METRICS_ID)),
+    options.getMetaMetricsId ?? (() => MOCK_METRICS_ID),
   });
 }
 
@@ -273,7 +273,7 @@ describe('RemoteFeatureFlagController', () => {
       });
       const controller = createController({
         clientConfigApiService,
-        getMetaMetricsId: () => Promise.resolve(MOCK_METRICS_ID),
+        getMetaMetricsId: () => MOCK_METRICS_ID,
       });
       await controller.updateRemoteFeatureFlags();
 
@@ -291,7 +291,7 @@ describe('RemoteFeatureFlagController', () => {
       });
       const controller = createController({
         clientConfigApiService,
-        getMetaMetricsId: () => Promise.resolve(MOCK_METRICS_ID),
+        getMetaMetricsId: () => MOCK_METRICS_ID,
       });
       await controller.updateRemoteFeatureFlags();
 
@@ -299,25 +299,6 @@ describe('RemoteFeatureFlagController', () => {
         controller.state.remoteFeatureFlags;
       expect(nonThresholdFlags).toStrictEqual(MOCK_FLAGS);
     });
-
-    it('handles synchronous metaMetricsId', async () => {
-      const clientConfigApiService = buildClientConfigApiService({
-        remoteFeatureFlags: MOCK_FLAGS_WITH_THRESHOLD,
-      });
-      const controller = createController({
-        clientConfigApiService,
-        getMetaMetricsId: () => MOCK_METRICS_ID,
-      });
-
-      await controller.updateRemoteFeatureFlags();
-
-      expect(
-        controller.state.remoteFeatureFlags.testFlagForThreshold,
-      ).toStrictEqual({
-        name: 'groupC',
-        value: 'valueC',
-      });
-    });
   });
 
   describe('enable and disable', () => {
diff --git a/packages/remote-feature-flag-controller/src/remote-feature-flag-controller.ts b/packages/remote-feature-flag-controller/src/remote-feature-flag-controller.ts
index 54076f0fb4..afb35032fe 100644
--- a/packages/remote-feature-flag-controller/src/remote-feature-flag-controller.ts
+++ b/packages/remote-feature-flag-controller/src/remote-feature-flag-controller.ts
@@ -102,7 +102,7 @@ export class RemoteFeatureFlagController extends BaseController<
 
   #inProgressFlagUpdate?: Promise<ServiceResponse>;
 
-  #getMetaMetricsId: () => string | Promise<string>;
+  #getMetaMetricsId: () => string;
 
   /**
    * Constructs a new RemoteFeatureFlagController instance.
@@ -126,7 +126,7 @@ export class RemoteFeatureFlagController extends BaseController<
     messenger: RemoteFeatureFlagControllerMessenger;
     state?: Partial<RemoteFeatureFlagControllerState>;
     clientConfigApiService: AbstractClientConfigApiService;
-    getMetaMetricsId: () => string | Promise<string>;
+    getMetaMetricsId: () => string;
     fetchInterval?: number;
     disabled?: boolean;
   }) {
@@ -208,11 +208,7 @@ export class RemoteFeatureFlagController extends BaseController<
     remoteFeatureFlags: FeatureFlags,
   ): Promise<FeatureFlags> {
     const processedRemoteFeatureFlags: FeatureFlags = {};
-    const metaMetricsIdResult = this.#getMetaMetricsId();
-    const metaMetricsId =
-      metaMetricsIdResult instanceof Promise
-        ? await metaMetricsIdResult
-        : metaMetricsIdResult;
+    const metaMetricsId = this.#getMetaMetricsId();
 
     const clientType = this.#clientConfigApiService.getClient();
     const thresholdValue = generateDeterministicRandomNumber(