diff --git a/packages/backend-app-api/src/wiring/BackendInitializer.test.ts b/packages/backend-app-api/src/wiring/BackendInitializer.test.ts
index 79f0f36540..1c0bf5a0ef 100644
--- a/packages/backend-app-api/src/wiring/BackendInitializer.test.ts
+++ b/packages/backend-app-api/src/wiring/BackendInitializer.test.ts
@@ -28,8 +28,6 @@ import { BackendInitializer } from './BackendInitializer';
 import { mockServices } from '@backstage/backend-test-utils';
 import { BackendStartupError } from './BackendStartupError';
 
-const ID_PATTERN = /^[a-z][a-z0-9]*(?:-[a-z0-9]+)*$/i;
-
 const baseFactories = [
   mockServices.rootLifecycle.factory(),
   mockServices.lifecycle.factory(),
@@ -1013,53 +1011,6 @@ describe('BackendInitializer', () => {
       "Service or extension point dependencies of module 'test-mod' for plugin 'test' are missing for the following ref(s): serviceRef{a}",
     );
   });
-  it('should reject plugins with invalid pluginId', async () => {
-    const init = new BackendInitializer(baseFactories);
-    init.add(
-      createBackendPlugin({
-        pluginId: 'test:invalid&id',
-        register(reg) {
-          reg.registerInit({
-            deps: {},
-            async init() {},
-          });
-        },
-      }),
-    );
-    await expect(init.start()).rejects.toThrow(
-      `Invalid pluginId 'test:invalid&id', must match the pattern ${ID_PATTERN} (letters, digits, and dashes only, starting with a letter)`,
-    );
-  });
-
-  it('should reject modules with invalid moduleId', async () => {
-    const init = new BackendInitializer(baseFactories);
-    init.add(
-      createBackendPlugin({
-        pluginId: 'test',
-        register(reg) {
-          reg.registerInit({
-            deps: {},
-            async init() {},
-          });
-        },
-      }),
-    );
-    init.add(
-      createBackendModule({
-        pluginId: 'test',
-        moduleId: 'invalid:module&id',
-        register(reg) {
-          reg.registerInit({
-            deps: {},
-            async init() {},
-          });
-        },
-      }),
-    );
-    await expect(init.start()).rejects.toThrow(
-      `Invalid moduleId 'invalid:module&id' for plugin 'test', must match the pattern ${ID_PATTERN} (letters, digits, and dashes only, starting with a letter)`,
-    );
-  });
 
   it('should properly load double-default CJS modules', async () => {
     expect.assertions(3);
diff --git a/packages/backend-plugin-api/src/wiring/createBackendModule.test.ts b/packages/backend-plugin-api/src/wiring/createBackendModule.test.ts
index 4d927c86f6..20b3599148 100644
--- a/packages/backend-plugin-api/src/wiring/createBackendModule.test.ts
+++ b/packages/backend-plugin-api/src/wiring/createBackendModule.test.ts
@@ -15,6 +15,7 @@
  */
 
 import { createServiceRef } from '../services';
+import { ID_PATTERN } from './constants';
 import { createBackendModule } from './createBackendModule';
 import { createExtensionPoint } from './createExtensionPoint';
 import { InternalBackendRegistrations } from './types';
@@ -77,4 +78,20 @@ describe('createBackendModule', () => {
 
     expect(plugin.$$type).toEqual('@backstage/BackendFeature');
   });
+  it('should reject modules with invalid moduleId', async () => {
+    expect(() =>
+      createBackendModule({
+        pluginId: 'test',
+        moduleId: 'invalid:module&id',
+        register(reg) {
+          reg.registerInit({
+            deps: {},
+            async init() {},
+          });
+        },
+      }),
+    ).toThrow(
+      `Invalid moduleId 'invalid:module&id' for plugin 'test', must match the pattern ${ID_PATTERN} (letters, digits, and dashes only, starting with a letter)`,
+    );
+  });
 });
diff --git a/packages/backend-plugin-api/src/wiring/createBackendPlugin.test.ts b/packages/backend-plugin-api/src/wiring/createBackendPlugin.test.ts
index 5acd8e46d7..4759bd2754 100644
--- a/packages/backend-plugin-api/src/wiring/createBackendPlugin.test.ts
+++ b/packages/backend-plugin-api/src/wiring/createBackendPlugin.test.ts
@@ -15,6 +15,7 @@
  */
 
 import { createServiceRef } from '../services';
+import { ID_PATTERN } from './constants';
 import { createBackendPlugin } from './createBackendPlugin';
 import { createExtensionPoint } from './createExtensionPoint';
 import { InternalBackendRegistrations } from './types';
@@ -90,4 +91,19 @@ describe('createBackendPlugin', () => {
 
     expect(plugin.$$type).toEqual('@backstage/BackendFeature');
   });
+  it('should reject plugins with invalid pluginId', async () => {
+    expect(() =>
+      createBackendPlugin({
+        pluginId: 'test:invalid&id',
+        register(reg) {
+          reg.registerInit({
+            deps: {},
+            async init() {},
+          });
+        },
+      }),
+    ).toThrow(
+      `Invalid pluginId 'test:invalid&id', must match the pattern ${ID_PATTERN} (letters, digits, and dashes only, starting with a letter)`,
+    );
+  });
 });
diff --git a/packages/frontend-plugin-api/src/wiring/createFrontendPlugin.test.ts b/packages/frontend-plugin-api/src/wiring/createFrontendPlugin.test.ts
index a3226721a1..1e1f7e1a84 100644
--- a/packages/frontend-plugin-api/src/wiring/createFrontendPlugin.test.ts
+++ b/packages/frontend-plugin-api/src/wiring/createFrontendPlugin.test.ts
@@ -142,6 +142,17 @@ describe('createFrontendPlugin', () => {
     expect(String(plugin)).toBe('Plugin{id=test}');
   });
 
+  it('should warn about invalid plugin IDs', () => {
+    const consoleWarn = jest
+      .spyOn(console, 'warn')
+      .mockImplementation(() => {});
+    createFrontendPlugin({ pluginId: 'invalid&id' });
+    expect(consoleWarn).toHaveBeenCalledWith(
+      expect.stringContaining("The pluginId 'invalid&id' will be invalid soon"),
+    );
+    consoleWarn.mockRestore();
+  });
+
   it('should create a plugin with extension instances', async () => {
     const plugin = createFrontendPlugin({
       pluginId: 'test',