diff --git a/common/api-review/vertexai.api.md b/common/api-review/vertexai.api.md
index 0a925cf580c..14177f133f4 100644
--- a/common/api-review/vertexai.api.md
+++ b/common/api-review/vertexai.api.md
@@ -721,6 +721,7 @@ export class VertexAIError extends FirebaseError {
 
 // @public
 export const enum VertexAIErrorCode {
+    API_NOT_ENABLED = "api-not-enabled",
     ERROR = "error",
     FETCH_ERROR = "fetch-error",
     INVALID_CONTENT = "invalid-content",
diff --git a/packages/vertexai/src/constants.ts b/packages/vertexai/src/constants.ts
index 97f6d813abc..3ff894f354b 100644
--- a/packages/vertexai/src/constants.ts
+++ b/packages/vertexai/src/constants.ts
@@ -21,9 +21,9 @@ export const VERTEX_TYPE = 'vertexAI';
 
 export const DEFAULT_LOCATION = 'us-central1';
 
-export const DEFAULT_BASE_URL = 'https://firebaseml.googleapis.com';
+export const DEFAULT_BASE_URL = 'https://firebasevertexai.googleapis.com';
 
-export const DEFAULT_API_VERSION = 'v2beta';
+export const DEFAULT_API_VERSION = 'v1beta';
 
 export const PACKAGE_VERSION = version;
 
diff --git a/packages/vertexai/src/methods/generate-content.test.ts b/packages/vertexai/src/methods/generate-content.test.ts
index 51fa82dccc9..fd12964c4bc 100644
--- a/packages/vertexai/src/methods/generate-content.test.ts
+++ b/packages/vertexai/src/methods/generate-content.test.ts
@@ -220,4 +220,18 @@ describe('generateContent()', () => {
     ).to.be.rejectedWith(/400.*invalid argument/);
     expect(mockFetch).to.be.called;
   });
+  it('api not enabled (403)', async () => {
+    const mockResponse = getMockResponse(
+      'unary-failure-firebasevertexai-api-not-enabled.json'
+    );
+    const mockFetch = stub(globalThis, 'fetch').resolves({
+      ok: false,
+      status: 403,
+      json: mockResponse.json
+    } as Response);
+    await expect(
+      generateContent(fakeApiSettings, 'model', fakeRequestParams)
+    ).to.be.rejectedWith(/firebasevertexai\.googleapis.*my-project/);
+    expect(mockFetch).to.be.called;
+  });
 });
diff --git a/packages/vertexai/src/requests/request.test.ts b/packages/vertexai/src/requests/request.test.ts
index 16a1ece2c7e..95e37631472 100644
--- a/packages/vertexai/src/requests/request.test.ts
+++ b/packages/vertexai/src/requests/request.test.ts
@@ -24,6 +24,7 @@ import { ApiSettings } from '../types/internal';
 import { DEFAULT_API_VERSION } from '../constants';
 import { VertexAIErrorCode } from '../types';
 import { VertexAIError } from '../errors';
+import { getMockResponse } from '../../test-utils/mock-response';
 
 use(sinonChai);
 use(chaiAsPromised);
@@ -357,4 +358,28 @@ describe('request methods', () => {
       expect(fetchStub).to.be.calledOnce;
     });
   });
+  it('Network error, API not enabled', async () => {
+    const mockResponse = getMockResponse(
+      'unary-failure-firebasevertexai-api-not-enabled.json'
+    );
+    const fetchStub = stub(globalThis, 'fetch').resolves(
+      mockResponse as Response
+    );
+    try {
+      await makeRequest(
+        'models/model-name',
+        Task.GENERATE_CONTENT,
+        fakeApiSettings,
+        false,
+        ''
+      );
+    } catch (e) {
+      expect((e as VertexAIError).code).to.equal(
+        VertexAIErrorCode.API_NOT_ENABLED
+      );
+      expect((e as VertexAIError).message).to.include('my-project');
+      expect((e as VertexAIError).message).to.include('googleapis.com');
+    }
+    expect(fetchStub).to.be.calledOnce;
+  });
 });
diff --git a/packages/vertexai/src/requests/request.ts b/packages/vertexai/src/requests/request.ts
index eac99a23038..a81e2d32d89 100644
--- a/packages/vertexai/src/requests/request.ts
+++ b/packages/vertexai/src/requests/request.ts
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-import { RequestOptions, VertexAIErrorCode } from '../types';
+import { ErrorDetails, RequestOptions, VertexAIErrorCode } from '../types';
 import { VertexAIError } from '../errors';
 import { ApiSettings } from '../types/internal';
 import {
@@ -151,6 +151,34 @@ export async function makeRequest(
       } catch (e) {
         // ignored
       }
+      if (
+        response.status === 403 &&
+        errorDetails.some(
+          (detail: ErrorDetails) => detail.reason === 'SERVICE_DISABLED'
+        ) &&
+        errorDetails.some((detail: ErrorDetails) =>
+          (
+            detail.links as Array<Record<string, string>>
+          )?.[0]?.description.includes(
+            'Google developers console API activation'
+          )
+        )
+      ) {
+        throw new VertexAIError(
+          VertexAIErrorCode.API_NOT_ENABLED,
+          `The Vertex AI for Firebase SDK requires the Firebase Vertex AI API ` +
+            `firebasevertexai.googleapis.com to be enabled for your ` +
+            `project. Get started in the Firebase Console` +
+            ` (https://console.firebase.google.com/project/${url.apiSettings.project}/genai/vertex)` +
+            ` or verify that the API is enabled in the Google Cloud` +
+            ` Console (https://console.developers.google.com/apis/api/firebasevertexai.googleapis.com/overview?project=${url.apiSettings.project}).`,
+          {
+            status: response.status,
+            statusText: response.statusText,
+            errorDetails
+          }
+        );
+      }
       throw new VertexAIError(
         VertexAIErrorCode.FETCH_ERROR,
         `Error fetching from ${url}: [${response.status} ${response.statusText}] ${message}`,
@@ -165,6 +193,7 @@ export async function makeRequest(
     let err = e as Error;
     if (
       (e as VertexAIError).code !== VertexAIErrorCode.FETCH_ERROR &&
+      (e as VertexAIError).code !== VertexAIErrorCode.API_NOT_ENABLED &&
       e instanceof Error
     ) {
       err = new VertexAIError(
diff --git a/packages/vertexai/src/types/error.ts b/packages/vertexai/src/types/error.ts
index d624e64fa07..aaaf19f05b3 100644
--- a/packages/vertexai/src/types/error.ts
+++ b/packages/vertexai/src/types/error.ts
@@ -78,6 +78,9 @@ export const enum VertexAIErrorCode {
   /** An error associated with a Content object.  */
   INVALID_CONTENT = 'invalid-content',
 
+  /** An error due to the Firebase API not being enabled in the Console. */
+  API_NOT_ENABLED = 'api-not-enabled',
+
   /** An error due to invalid Schema input.  */
   INVALID_SCHEMA = 'invalid-schema',