diff --git a/.changeset/fair-cheetahs-suffer.md b/.changeset/fair-cheetahs-suffer.md
new file mode 100644
index 0000000000..a41237acaa
--- /dev/null
+++ b/.changeset/fair-cheetahs-suffer.md
@@ -0,0 +1,7 @@
+---
+'@backstage/plugin-notifications-backend': patch
+'@backstage/plugin-notifications-common': patch
+'@backstage/plugin-notifications-node': patch
+---
+
+Move notification origin resolving to backend with new auth
diff --git a/plugins/notifications-backend/src/plugin.ts b/plugins/notifications-backend/src/plugin.ts
index 1d81818e30..29d444efd3 100644
--- a/plugins/notifications-backend/src/plugin.ts
+++ b/plugins/notifications-backend/src/plugin.ts
@@ -61,22 +61,20 @@ export const notificationsPlugin = createBackendPlugin({
       deps: {
         auth: coreServices.auth,
         httpAuth: coreServices.httpAuth,
+        userInfo: coreServices.userInfo,
         httpRouter: coreServices.httpRouter,
         logger: coreServices.logger,
-        identity: coreServices.identity,
         database: coreServices.database,
-        tokenManager: coreServices.tokenManager,
         discovery: coreServices.discovery,
         signals: signalService,
       },
       async init({
         auth,
         httpAuth,
+        userInfo,
         httpRouter,
         logger,
-        identity,
         database,
-        tokenManager,
         discovery,
         signals,
       }) {
@@ -84,10 +82,9 @@ export const notificationsPlugin = createBackendPlugin({
           await createRouter({
             auth,
             httpAuth,
+            userInfo,
             logger,
-            identity,
             database,
-            tokenManager,
             discovery,
             signalService: signals,
             processors: processingExtensions.processors,
diff --git a/plugins/notifications-backend/src/service/router.test.ts b/plugins/notifications-backend/src/service/router.test.ts
index 3152b1b07f..13cb5e2f54 100644
--- a/plugins/notifications-backend/src/service/router.test.ts
+++ b/plugins/notifications-backend/src/service/router.test.ts
@@ -17,16 +17,14 @@ import {
   DatabaseManager,
   getVoidLogger,
   PluginDatabaseManager,
-  PluginEndpointDiscovery,
-  TokenManager,
 } from '@backstage/backend-common';
 import express from 'express';
 import request from 'supertest';
 
 import { createRouter } from './router';
-import { IdentityApi } from '@backstage/plugin-auth-node';
 import { ConfigReader } from '@backstage/config';
 import { SignalService } from '@backstage/plugin-signals-node';
+import { mockServices } from '@backstage/backend-test-utils';
 
 function createDatabase(): PluginDatabaseManager {
   return DatabaseManager.fromConfig(
@@ -44,40 +42,24 @@ function createDatabase(): PluginDatabaseManager {
 describe('createRouter', () => {
   let app: express.Express;
 
-  const identityMock: IdentityApi = {
-    async getIdentity() {
-      return {
-        identity: {
-          type: 'user',
-          ownershipEntityRefs: [],
-          userEntityRef: 'user:default/guest',
-        },
-        token: 'no-token',
-      };
-    },
-  };
-  const mockedTokenManager: jest.Mocked<TokenManager> = {
-    getToken: jest.fn(),
-    authenticate: jest.fn(),
-  };
-
-  const discovery: jest.Mocked<PluginEndpointDiscovery> = {
-    getBaseUrl: jest.fn(),
-    getExternalBaseUrl: jest.fn(),
-  };
-
   const signalService: jest.Mocked<SignalService> = {
     publish: jest.fn(),
   };
 
+  const discovery = mockServices.discovery();
+  const userInfo = mockServices.userInfo();
+  const httpAuth = mockServices.httpAuth();
+  const auth = mockServices.auth();
+
   beforeAll(async () => {
     const router = await createRouter({
       logger: getVoidLogger(),
-      identity: identityMock,
       database: createDatabase(),
-      tokenManager: mockedTokenManager,
       discovery,
       signalService,
+      userInfo,
+      httpAuth,
+      auth,
     });
     app = express().use(router);
   });
diff --git a/plugins/notifications-backend/src/service/router.ts b/plugins/notifications-backend/src/service/router.ts
index 78d44dcd44..221606e2da 100644
--- a/plugins/notifications-backend/src/service/router.ts
+++ b/plugins/notifications-backend/src/service/router.ts
@@ -13,15 +13,9 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-import {
-  createLegacyAuthAdapters,
-  errorHandler,
-  PluginDatabaseManager,
-  TokenManager,
-} from '@backstage/backend-common';
+import { errorHandler, PluginDatabaseManager } from '@backstage/backend-common';
 import express, { Request } from 'express';
 import Router from 'express-promise-router';
-import { IdentityApi } from '@backstage/plugin-auth-node';
 import {
   DatabaseNotificationsStore,
   NotificationGetOptions,
@@ -36,12 +30,13 @@ import {
   stringifyEntityRef,
 } from '@backstage/catalog-model';
 import { NotificationProcessor } from '@backstage/plugin-notifications-node';
-import { AuthenticationError, InputError } from '@backstage/errors';
+import { InputError } from '@backstage/errors';
 import {
   AuthService,
   DiscoveryService,
   HttpAuthService,
   LoggerService,
+  UserInfoService,
 } from '@backstage/backend-plugin-api';
 import { SignalService } from '@backstage/plugin-signals-node';
 import {
@@ -53,15 +48,14 @@ import {
 /** @internal */
 export interface RouterOptions {
   logger: LoggerService;
-  identity: IdentityApi;
   database: PluginDatabaseManager;
-  tokenManager: TokenManager;
   discovery: DiscoveryService;
+  auth: AuthService;
+  httpAuth: HttpAuthService;
+  userInfo: UserInfoService;
   signalService?: SignalService;
   catalog?: CatalogApi;
   processors?: NotificationProcessor[];
-  auth?: AuthService;
-  httpAuth?: HttpAuthService;
 }
 
 /** @internal */
@@ -71,7 +65,9 @@ export async function createRouter(
   const {
     logger,
     database,
-    identity,
+    auth,
+    httpAuth,
+    userInfo,
     discovery,
     catalog,
     processors,
@@ -82,14 +78,10 @@ export async function createRouter(
     catalog ?? new CatalogClient({ discoveryApi: discovery });
   const store = await DatabaseNotificationsStore.create({ database });
 
-  const { auth, httpAuth } = createLegacyAuthAdapters(options);
-
   const getUser = async (req: Request<unknown>) => {
-    const user = await identity.getIdentity({ request: req });
-    if (!user) {
-      throw new AuthenticationError();
-    }
-    return user.identity.userEntityRef;
+    const credentials = await httpAuth.credentials(req, { allow: ['user'] });
+    const info = await userInfo.getUserInfo(credentials);
+    return info.userEntityRef;
   };
 
   const getUsersForEntityRef = async (
@@ -277,18 +269,16 @@ export async function createRouter(
   });
 
   // Add new notification
-  // Allowed only for service-to-service authentication, uses `getUsersForEntityRef` to retrieve recipients for
-  // specific entity reference
   router.post('/', async (req, res) => {
-    const { recipients, origin, payload } = req.body;
+    const { recipients, payload } = req.body;
     const notifications = [];
     let users = [];
 
-    await httpAuth.credentials(req, { allow: ['service'] });
+    const credentials = await httpAuth.credentials(req, { allow: ['service'] });
 
-    const { title, link, scope } = payload;
+    const { title, scope } = payload;
 
-    if (!recipients || !title || !origin || !link) {
+    if (!recipients || !title) {
       logger.error(`Invalid notification request received`);
       throw new InputError();
     }
@@ -305,6 +295,7 @@ export async function createRouter(
       throw new InputError();
     }
 
+    const origin = credentials.principal.subject;
     const baseNotification: Omit<Notification, 'id' | 'user'> = {
       payload: {
         ...payload,
diff --git a/plugins/notifications-backend/src/service/standaloneServer.ts b/plugins/notifications-backend/src/service/standaloneServer.ts
index c4927e8b38..817c35f739 100644
--- a/plugins/notifications-backend/src/service/standaloneServer.ts
+++ b/plugins/notifications-backend/src/service/standaloneServer.ts
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 import {
+  createLegacyAuthAdapters,
   createServiceBuilder,
   HostDiscovery,
   loadBackendConfig,
@@ -37,6 +38,11 @@ import {
   EventsService,
   EventsServiceSubscribeOptions,
 } from '@backstage/plugin-events-node';
+import {
+  AuthService,
+  HttpAuthService,
+  UserInfoService,
+} from '@backstage/backend-plugin-api';
 
 export interface ServerOptions {
   port: number;
@@ -107,15 +113,25 @@ export async function startStandaloneServer(
   };
 
   const signalService = DefaultSignalService.create({ events });
+  // TODO: Move to use services instead this hack
+  const { auth, httpAuth, userInfo } = createLegacyAuthAdapters<
+    any,
+    { auth: AuthService; httpAuth: HttpAuthService; userInfo: UserInfoService }
+  >({
+    identity: identityMock,
+    tokenManager,
+    discovery,
+  });
 
   const router = await createRouter({
     logger,
-    identity: identityMock,
     database: dbMock,
     catalog: catalogApi,
     discovery,
-    tokenManager,
     signalService,
+    auth,
+    httpAuth,
+    userInfo,
   });
 
   let service = createServiceBuilder(module)
diff --git a/plugins/notifications-common/api-report.md b/plugins/notifications-common/api-report.md
index 55c9b28489..bd01aa7f5a 100644
--- a/plugins/notifications-common/api-report.md
+++ b/plugins/notifications-common/api-report.md
@@ -27,7 +27,7 @@ export type NotificationPayload = {
   title: string;
   description?: string;
   link?: string;
-  severity: NotificationSeverity;
+  severity?: NotificationSeverity;
   topic?: string;
   scope?: string;
   icon?: string;
diff --git a/plugins/notifications-common/src/types.ts b/plugins/notifications-common/src/types.ts
index c338a772d7..2a5f803652 100644
--- a/plugins/notifications-common/src/types.ts
+++ b/plugins/notifications-common/src/types.ts
@@ -24,7 +24,7 @@ export type NotificationPayload = {
   link?: string;
   // TODO: Add support for additional links
   // additionalLinks?: string[];
-  severity: NotificationSeverity;
+  severity?: NotificationSeverity;
   topic?: string;
   scope?: string;
   icon?: string;
diff --git a/plugins/notifications-node/api-report.md b/plugins/notifications-node/api-report.md
index 24ae31904c..1e0e5718d1 100644
--- a/plugins/notifications-node/api-report.md
+++ b/plugins/notifications-node/api-report.md
@@ -51,7 +51,6 @@ export const notificationService: ServiceRef<NotificationService, 'plugin'>;
 export type NotificationServiceOptions = {
   auth: AuthService;
   discovery: DiscoveryService;
-  pluginId: string;
 };
 
 // @public (undocumented)
diff --git a/plugins/notifications-node/src/lib.ts b/plugins/notifications-node/src/lib.ts
index 2ba33608b4..3e0095f72c 100644
--- a/plugins/notifications-node/src/lib.ts
+++ b/plugins/notifications-node/src/lib.ts
@@ -31,13 +31,11 @@ export const notificationService = createServiceRef<NotificationService>({
       deps: {
         auth: coreServices.auth,
         discovery: coreServices.discovery,
-        pluginMetadata: coreServices.pluginMetadata,
       },
-      factory({ auth, discovery, pluginMetadata }) {
+      factory({ auth, discovery }) {
         return DefaultNotificationService.create({
           auth,
           discovery,
-          pluginId: pluginMetadata.getId(),
         });
       },
     }),
diff --git a/plugins/notifications-node/src/service/DefaultNotificationService.test.ts b/plugins/notifications-node/src/service/DefaultNotificationService.test.ts
index 9d8f5b82d9..4711f3de18 100644
--- a/plugins/notifications-node/src/service/DefaultNotificationService.test.ts
+++ b/plugins/notifications-node/src/service/DefaultNotificationService.test.ts
@@ -42,7 +42,6 @@ describe('DefaultNotificationService', () => {
     service = DefaultNotificationService.create({
       auth,
       discovery,
-      pluginId: 'test',
     });
   });
 
@@ -58,7 +57,7 @@ describe('DefaultNotificationService', () => {
           `${await discovery.getBaseUrl('notifications')}/`,
           async (req, res, ctx) => {
             const json = await req.json();
-            expect(json).toEqual({ ...body, origin: 'plugin-test' });
+            expect(json).toEqual(body);
             expect(req.headers.get('Authorization')).toBe(
               mockCredentials.service.header({
                 onBehalfOf: await auth.getOwnServiceCredentials(),
@@ -83,7 +82,7 @@ describe('DefaultNotificationService', () => {
           `${await discovery.getBaseUrl('notifications')}/`,
           async (req, res, ctx) => {
             const json = await req.json();
-            expect(json).toEqual({ ...body, origin: 'plugin-test' });
+            expect(json).toEqual(body);
             expect(req.headers.get('Authorization')).toBe(
               mockCredentials.service.header({
                 onBehalfOf: await auth.getOwnServiceCredentials(),
diff --git a/plugins/notifications-node/src/service/DefaultNotificationService.ts b/plugins/notifications-node/src/service/DefaultNotificationService.ts
index ef06133d36..bd7712ff6f 100644
--- a/plugins/notifications-node/src/service/DefaultNotificationService.ts
+++ b/plugins/notifications-node/src/service/DefaultNotificationService.ts
@@ -22,7 +22,6 @@ import { NotificationPayload } from '@backstage/plugin-notifications-common';
 export type NotificationServiceOptions = {
   auth: AuthService;
   discovery: DiscoveryService;
-  pluginId: string;
 };
 
 /** @public */
@@ -45,17 +44,12 @@ export class DefaultNotificationService implements NotificationService {
   private constructor(
     private readonly discovery: DiscoveryService,
     private readonly auth: AuthService,
-    private readonly pluginId: string,
   ) {}
 
   static create(
     options: NotificationServiceOptions,
   ): DefaultNotificationService {
-    return new DefaultNotificationService(
-      options.discovery,
-      options.auth,
-      options.pluginId,
-    );
+    return new DefaultNotificationService(options.discovery, options.auth);
   }
 
   async send(notification: NotificationSendOptions): Promise<void> {
@@ -65,13 +59,10 @@ export class DefaultNotificationService implements NotificationService {
         onBehalfOf: await this.auth.getOwnServiceCredentials(),
         targetPluginId: 'notifications',
       });
+
       const response = await fetch(`${baseUrl}/`, {
         method: 'POST',
-        body: JSON.stringify({
-          ...notification,
-          // TODO: Should retrieve this in the backend from service auth instead
-          origin: `plugin-${this.pluginId}`,
-        }),
+        body: JSON.stringify(notification),
         headers: {
           'Content-Type': 'application/json',
           Accept: 'application/json',