diff --git a/packages/backend-test-utils/report.api.md b/packages/backend-test-utils/report.api.md
index 4f6998e1ce..9ebf02d5b8 100644
--- a/packages/backend-test-utils/report.api.md
+++ b/packages/backend-test-utils/report.api.md
@@ -3,12 +3,9 @@
 > Do not edit this file. It is a report generated by [API Extractor](https://api-extractor.com/).
 
 ```ts
-/// <reference types="express" />
 /// <reference types="jest" />
 /// <reference types="node" />
-/// <reference types="qs" />
 
-import type { AuditorOptions } from '@backstage/backend-defaults/auditor';
 import { AuditorService } from '@backstage/backend-plugin-api';
 import { AuthService } from '@backstage/backend-plugin-api';
 import { Backend } from '@backstage/backend-app-api';
@@ -37,6 +34,7 @@ import { ParamsDictionary } from 'express-serve-static-core';
 import { ParsedQs } from 'qs';
 import { PermissionsRegistryService } from '@backstage/backend-plugin-api';
 import { PermissionsService } from '@backstage/backend-plugin-api';
+import type { RootAuditorOptions } from '@backstage/backend-defaults/auditor';
 import { RootConfigService } from '@backstage/backend-plugin-api';
 import { RootHealthService } from '@backstage/backend-plugin-api';
 import { RootHttpRouterService } from '@backstage/backend-plugin-api';
@@ -156,14 +154,14 @@ export function mockErrorHandler(): ErrorRequestHandler<
 // @public
 export namespace mockServices {
   export function auditor(
-    options?: Omit<auditor.Options, 'plugin'> & {
+    options?: auditor.Options & {
       pluginId?: string;
     },
   ): AuditorService;
   // (undocumented)
   export namespace auditor {
     // (undocumented)
-    export type Options = Omit<AuditorOptions, 'format' | 'transports'>;
+    export type Options = RootAuditorOptions;
     const // (undocumented)
       factory: (
         options?: auditor.Options,
diff --git a/packages/backend-test-utils/src/next/services/MockAuditorService.test.ts b/packages/backend-test-utils/src/next/services/MockAuditorService.test.ts
index 5dfbe560e2..b11f633ea8 100644
--- a/packages/backend-test-utils/src/next/services/MockAuditorService.test.ts
+++ b/packages/backend-test-utils/src/next/services/MockAuditorService.test.ts
@@ -15,7 +15,7 @@
  */
 
 import type { ErrorLike } from '@backstage/errors';
-import { MockAuditorService } from './MockAuditorService';
+import { MockRootAuditorService } from './MockAuditorService';
 import { MockAuthService } from './MockAuthService';
 import { MockHttpAuthService } from './MockHttpAuthService';
 import { mockCredentials } from './mockCredentials';
@@ -25,81 +25,21 @@ describe('MockAuditorService', () => {
     jest.resetAllMocks();
   });
 
-  it('should error without plugin service', async () => {
-    const auditor = MockAuditorService.create();
-    await expect(
-      auditor.createEvent({
-        eventId: 'test-event',
-      }),
-    ).rejects.toThrow(
-      `The core service 'plugin' was not provided during the auditor's instantiation`,
-    );
-  });
-
-  it('should error without auth service', async () => {
-    const pluginId = 'test-plugin';
-
-    const auditor = MockAuditorService.create().child(
-      {},
-      {
-        plugin: {
-          getId: () => pluginId,
-        },
-      },
-    );
-
-    await expect(
-      auditor.createEvent({
-        eventId: 'test-event',
-      }),
-    ).rejects.toThrow(
-      `The core service 'auth' was not provided during the auditor's instantiation`,
-    );
-  });
-
-  it('should error without httpAuth service', async () => {
-    const pluginId = 'test-plugin';
-
-    const auditor = MockAuditorService.create().child(
-      {},
-      {
-        plugin: {
-          getId: () => pluginId,
-        },
-        auth: new MockAuthService({
-          pluginId,
-          disableDefaultAuthPolicy: false,
-        }),
-      },
-    );
-
-    await expect(
-      auditor.createEvent({
-        eventId: 'test-event',
-      }),
-    ).rejects.toThrow(
-      `The core service 'httpAuth' was not provided during the auditor's instantiation`,
-    );
-  });
-
   it('should log', async () => {
     jest.spyOn(console, 'log').mockImplementation(() => {});
 
     const pluginId = 'test-plugin';
 
-    const auditor = MockAuditorService.create().child(
-      {},
-      {
-        plugin: {
-          getId: () => pluginId,
-        },
-        auth: new MockAuthService({
-          pluginId,
-          disableDefaultAuthPolicy: false,
-        }),
-        httpAuth: new MockHttpAuthService(pluginId, mockCredentials.user()),
+    const auditor = MockRootAuditorService.create().forPlugin({
+      plugin: {
+        getId: () => pluginId,
       },
-    );
+      auth: new MockAuthService({
+        pluginId,
+        disableDefaultAuthPolicy: false,
+      }),
+      httpAuth: new MockHttpAuthService(pluginId, mockCredentials.user()),
+    });
 
     await auditor.createEvent({
       eventId: 'test-event',
@@ -113,19 +53,16 @@ describe('MockAuditorService', () => {
 
     const pluginId = 'test-plugin';
 
-    const auditor = MockAuditorService.create().child(
-      {},
-      {
-        plugin: {
-          getId: () => pluginId,
-        },
-        auth: new MockAuthService({
-          pluginId,
-          disableDefaultAuthPolicy: false,
-        }),
-        httpAuth: new MockHttpAuthService(pluginId, mockCredentials.user()),
+    const auditor = MockRootAuditorService.create().forPlugin({
+      plugin: {
+        getId: () => pluginId,
       },
-    );
+      auth: new MockAuthService({
+        pluginId,
+        disableDefaultAuthPolicy: false,
+      }),
+      httpAuth: new MockHttpAuthService(pluginId, mockCredentials.user()),
+    });
 
     await auditor.createEvent({
       eventId: 'test-event',
@@ -139,19 +76,16 @@ describe('MockAuditorService', () => {
 
     const pluginId = 'test-plugin';
 
-    const auditor = MockAuditorService.create().child(
-      {},
-      {
-        plugin: {
-          getId: () => pluginId,
-        },
-        auth: new MockAuthService({
-          pluginId,
-          disableDefaultAuthPolicy: false,
-        }),
-        httpAuth: new MockHttpAuthService(pluginId, mockCredentials.user()),
+    const auditor = MockRootAuditorService.create().forPlugin({
+      plugin: {
+        getId: () => pluginId,
       },
-    );
+      auth: new MockAuthService({
+        pluginId,
+        disableDefaultAuthPolicy: false,
+      }),
+      httpAuth: new MockHttpAuthService(pluginId, mockCredentials.user()),
+    });
 
     const auditorEvent = await auditor.createEvent({
       eventId: 'test-event',
@@ -167,19 +101,16 @@ describe('MockAuditorService', () => {
 
     const pluginId = 'test-plugin';
 
-    const auditor = MockAuditorService.create().child(
-      {},
-      {
-        plugin: {
-          getId: () => pluginId,
-        },
-        auth: new MockAuthService({
-          pluginId,
-          disableDefaultAuthPolicy: false,
-        }),
-        httpAuth: new MockHttpAuthService(pluginId, mockCredentials.user()),
+    const auditor = MockRootAuditorService.create().forPlugin({
+      plugin: {
+        getId: () => pluginId,
       },
-    );
+      auth: new MockAuthService({
+        pluginId,
+        disableDefaultAuthPolicy: false,
+      }),
+      httpAuth: new MockHttpAuthService(pluginId, mockCredentials.user()),
+    });
 
     const auditorEvent = await auditor.createEvent({
       eventId: 'test-event',
diff --git a/packages/backend-test-utils/src/next/services/MockAuditorService.ts b/packages/backend-test-utils/src/next/services/MockAuditorService.ts
index 3e99986758..2d34ffae9e 100644
--- a/packages/backend-test-utils/src/next/services/MockAuditorService.ts
+++ b/packages/backend-test-utils/src/next/services/MockAuditorService.ts
@@ -26,27 +26,47 @@ import type {
   HttpAuthService,
   PluginMetadataService,
 } from '@backstage/backend-plugin-api';
-import { ForwardedError, ServiceUnavailableError } from '@backstage/errors';
+import { ForwardedError } from '@backstage/errors';
 import type { JsonObject } from '@backstage/types';
 import type { Request } from 'express';
 import type { mockServices } from './mockServices';
 
 export class MockAuditorService implements AuditorService {
-  readonly #options: mockServices.auditor.Options & {
-    auth?: AuthService;
-    httpAuth?: HttpAuthService;
-    plugin?: PluginMetadataService;
-  };
+  private readonly impl: MockRootAuditorService;
+  private readonly auth: AuthService;
+  private readonly httpAuth: HttpAuthService;
+  private readonly plugin: PluginMetadataService;
 
-  static create(options?: mockServices.auditor.Options): MockAuditorService {
-    return new MockAuditorService(options ?? {});
+  private constructor(
+    impl: MockRootAuditorService,
+    deps: {
+      auth: AuthService;
+      httpAuth: HttpAuthService;
+      plugin: PluginMetadataService;
+    },
+  ) {
+    this.impl = impl;
+    this.auth = deps.auth;
+    this.httpAuth = deps.httpAuth;
+    this.plugin = deps.plugin;
+  }
+
+  static create(
+    impl: MockRootAuditorService,
+    deps: {
+      auth: AuthService;
+      httpAuth: HttpAuthService;
+      plugin: PluginMetadataService;
+    },
+  ): AuditorService {
+    return new MockAuditorService(impl, deps);
   }
 
   private async log<TMeta extends JsonObject>(
     options: AuditorEventOptions<TMeta>,
   ): Promise<void> {
     const auditEvent = await this.reshapeAuditorEvent(options);
-    this.#log(...auditEvent);
+    this.impl.log(auditEvent);
   }
 
   async createEvent<TMeta extends JsonObject>(
@@ -89,57 +109,25 @@ export class MockAuditorService implements AuditorService {
     };
   }
 
-  child(
-    meta: JsonObject,
-    deps?: {
-      auth?: AuthService;
-      httpAuth?: HttpAuthService;
-      plugin?: PluginMetadataService;
-    },
-  ): AuditorService {
-    return new MockAuditorService({
-      ...this.#options,
-      auth: deps?.auth,
-      httpAuth: deps?.httpAuth,
-      plugin: deps?.plugin,
-      meta: {
-        ...this.#options.meta,
-        ...meta,
-      },
-    });
-  }
-
   private async getActorId(
     request?: Request<any, any, any, any, any>,
   ): Promise<string | undefined> {
-    if (!this.#options.auth) {
-      throw new ServiceUnavailableError(
-        `The core service 'auth' was not provided during the auditor's instantiation`,
-      );
-    }
-
-    if (!this.#options.httpAuth) {
-      throw new ServiceUnavailableError(
-        `The core service 'httpAuth' was not provided during the auditor's instantiation`,
-      );
-    }
-
     let credentials: BackstageCredentials =
-      await this.#options.auth.getOwnServiceCredentials();
+      await this.auth.getOwnServiceCredentials();
 
     if (request) {
       try {
-        credentials = await this.#options.httpAuth.credentials(request);
+        credentials = await this.httpAuth.credentials(request);
       } catch (error) {
         throw new ForwardedError('Could not resolve credentials', error);
       }
     }
 
-    if (this.#options.auth.isPrincipal(credentials, 'user')) {
+    if (this.auth.isPrincipal(credentials, 'user')) {
       return credentials.principal.userEntityRef;
     }
 
-    if (this.#options.auth.isPrincipal(credentials, 'service')) {
+    if (this.auth.isPrincipal(credentials, 'service')) {
       return credentials.principal.subject;
     }
 
@@ -151,14 +139,8 @@ export class MockAuditorService implements AuditorService {
   ): Promise<AuditorEvent> {
     const { eventId, severityLevel = 'low', request, ...rest } = options;
 
-    if (!this.#options.plugin) {
-      throw new ServiceUnavailableError(
-        `The core service 'plugin' was not provided during the auditor's instantiation`,
-      );
-    }
-
     const auditEvent: AuditorEvent = [
-      `${this.#options.plugin.getId()}.${eventId}`,
+      `${this.plugin.getId()}.${eventId}`,
       {
         severityLevel,
         actor: {
@@ -179,15 +161,32 @@ export class MockAuditorService implements AuditorService {
 
     return auditEvent;
   }
+}
 
-  private constructor(
-    options: mockServices.auditor.Options & {
-      auth?: AuthService;
-      httpAuth?: HttpAuthService;
-      plugin?: PluginMetadataService;
-    },
-  ) {
-    this.#options = options;
+export class MockRootAuditorService {
+  private readonly options: mockServices.auditor.Options;
+
+  private constructor(options?: mockServices.auditor.Options) {
+    this.options = options ?? {};
+  }
+
+  static create(
+    options?: mockServices.auditor.Options,
+  ): MockRootAuditorService {
+    return new MockRootAuditorService(options);
+  }
+
+  async log(auditEvent: AuditorEvent): Promise<void> {
+    this.#log(...auditEvent);
+  }
+
+  forPlugin(deps: {
+    auth: AuthService;
+    httpAuth: HttpAuthService;
+    plugin: PluginMetadataService;
+  }): AuditorService {
+    const impl = new MockRootAuditorService(this.options);
+    return MockAuditorService.create(impl, deps);
   }
 
   #log(message: string, meta?: AuditorEvent[1]) {
diff --git a/packages/backend-test-utils/src/next/services/mockServices.ts b/packages/backend-test-utils/src/next/services/mockServices.ts
index ad1ee24e5b..e5c8db185b 100644
--- a/packages/backend-test-utils/src/next/services/mockServices.ts
+++ b/packages/backend-test-utils/src/next/services/mockServices.ts
@@ -51,7 +51,7 @@ import {
 } from '@backstage/plugin-events-node';
 import { JsonObject } from '@backstage/types';
 import { Knex } from 'knex';
-import { MockAuditorService } from './MockAuditorService';
+import { MockRootAuditorService } from './MockAuditorService';
 import { MockAuthService } from './MockAuthService';
 import { MockHttpAuthService } from './MockHttpAuthService';
 import { MockRootLoggerService } from './MockRootLoggerService';
@@ -228,7 +228,7 @@ export namespace mockServices {
    * Creates a mock implementation of the `AuditorService`.
    */
   export function auditor(
-    options?: Omit<auditor.Options, 'plugin'> & {
+    options?: auditor.Options & {
       pluginId?: string;
     },
   ): AuditorService {
@@ -247,18 +247,19 @@ export namespace mockServices {
       getId: () => pluginId,
     };
 
-    const auditorMock = MockAuditorService.create({
+    const auditorMock = MockRootAuditorService.create({
       meta: options?.meta ? { ...options.meta, service } : { service },
     });
 
-    return auditorMock.child(
-      { pluginId },
-      { auth: mockAuth, httpAuth: mockHttpAuth, plugin: mockPlugin },
-    );
+    return auditorMock.forPlugin({
+      auth: mockAuth,
+      httpAuth: mockHttpAuth,
+      plugin: mockPlugin,
+    });
   }
 
   export namespace auditor {
-    export type Options = Omit<RootAuditorOptions, 'format' | 'transports'>;
+    export type Options = RootAuditorOptions;
 
     export const factory = (options?: auditor.Options) =>
       createServiceFactory({
@@ -271,23 +272,19 @@ export namespace mockServices {
         createRootContext() {
           const service = 'backstage';
 
-          return MockAuditorService.create({
+          return MockRootAuditorService.create({
             meta: options?.meta ? { ...options.meta, service } : { service },
           });
         },
         factory(
-          {
-            plugin,
+          { auth: mockAuth, httpAuth: mockHttpAuth, plugin: mockPlugin },
+          rootAuditor,
+        ) {
+          return rootAuditor.forPlugin({
             auth: mockAuth,
             httpAuth: mockHttpAuth,
             plugin: mockPlugin,
-          },
-          rootAuditor,
-        ) {
-          return rootAuditor.child(
-            { plugin: plugin.getId() },
-            { auth: mockAuth, httpAuth: mockHttpAuth, plugin: mockPlugin },
-          );
+          });
         },
       });