diff --git a/src/middleware/packages/activitypub/services/activitypub/subservices/api.ts b/src/middleware/packages/activitypub/services/activitypub/subservices/api.ts
index 3c9137c77..543e87493 100644
--- a/src/middleware/packages/activitypub/services/activitypub/subservices/api.ts
+++ b/src/middleware/packages/activitypub/services/activitypub/subservices/api.ts
@@ -11,7 +11,8 @@ import {
   parseJson,
   parseTurtle,
   parseFile,
-  saveDatasetMeta
+  saveDatasetMeta,
+  checkUsernameExists
 } from '@semapps/middlewares';
 
 import { ServiceSchema } from 'moleculer';
@@ -115,7 +116,7 @@ const ApiService = {
   },
   methods: {
     getBoxesRoute(actorsPath) {
-      const middlewares = [
+      let middlewares = [
         parseUrl,
         parseHeader,
         negotiateContentType,
@@ -127,6 +128,8 @@ const ApiService = {
         saveDatasetMeta
       ];
 
+      if (this.settings.podProvider) middlewares.unshift(checkUsernameExists);
+
       return {
         name: this.settings.podProvider ? 'boxes' : `boxes${actorsPath}`,
         path: actorsPath,
diff --git a/src/middleware/packages/crypto/signature/proxy.ts b/src/middleware/packages/crypto/signature/proxy.ts
index f0c5e4aee..1f964fa67 100644
--- a/src/middleware/packages/crypto/signature/proxy.ts
+++ b/src/middleware/packages/crypto/signature/proxy.ts
@@ -1,6 +1,6 @@
 import path from 'path';
 import urlJoin from 'url-join';
-import { parseHeader, parseFile, saveDatasetMeta } from '@semapps/middlewares';
+import { parseHeader, parseFile, saveDatasetMeta, checkUsernameExists } from '@semapps/middlewares';
 import fetch from 'node-fetch';
 // @ts-expect-error TS(2614): Module '"moleculer-web"' has no exported member 'E... Remove this comment to see the full error message
 import { Errors as E } from 'moleculer-web';
@@ -24,12 +24,15 @@ const ProxyService = {
   async started() {
     const basePath = await this.broker.call('ldp.getBasePath');
 
+    let middlewares = [parseHeader, parseFile, saveDatasetMeta];
+    if (this.settings.podProvider) middlewares.unshift(checkUsernameExists);
+
     const routeConfig = {
       name: 'proxy-endpoint',
       authorization: true,
       authentication: false,
       aliases: {
-        'POST /': [parseHeader, parseFile, saveDatasetMeta, 'signature.proxy.api_query'] // parseFile handles multipart/form-data
+        'POST /': [...middlewares, 'signature.proxy.api_query'] // parseFile handles multipart/form-data
       }
     };
 
diff --git a/src/middleware/packages/crypto/verifiable-credentials/vc-api-service.ts b/src/middleware/packages/crypto/verifiable-credentials/vc-api-service.ts
index be83cc802..8c37e429c 100644
--- a/src/middleware/packages/crypto/verifiable-credentials/vc-api-service.ts
+++ b/src/middleware/packages/crypto/verifiable-credentials/vc-api-service.ts
@@ -1,10 +1,8 @@
-import { parseHeader, negotiateAccept, parseJson } from '@semapps/middlewares';
+import { parseHeader, negotiateAccept, parseJson, checkUsernameExists } from '@semapps/middlewares';
 import path from 'node:path';
 import { ServiceSchema } from 'moleculer';
 import { VC_API_PATH } from '../constants';
 
-const middlewares = [parseHeader, parseJson, negotiateAccept];
-
 /**
  *
  * Verifiable Credentials API Service.
@@ -30,6 +28,9 @@ const VCApiService = {
     const basePath = await this.broker.call('ldp.getBasePath');
     const apiPath = path.join(basePath, this.settings.podProvider ? '/:username([^/.][^/]+)' : '', VC_API_PATH);
 
+    let middlewares = [parseHeader, parseJson, negotiateAccept];
+    if (this.settings.podProvider) middlewares.unshift(checkUsernameExists);
+
     // Credential routes.
     await this.broker.call('api.addRoute', {
       route: {
diff --git a/src/middleware/packages/ldp/routes/getCatchAllRoute.ts b/src/middleware/packages/ldp/routes/getCatchAllRoute.ts
index 95049886e..9b5725d50 100644
--- a/src/middleware/packages/ldp/routes/getCatchAllRoute.ts
+++ b/src/middleware/packages/ldp/routes/getCatchAllRoute.ts
@@ -9,11 +9,12 @@ import {
   parseJson,
   parseTurtle,
   parseFile,
-  saveDatasetMeta
+  saveDatasetMeta,
+  checkUsernameExists
 } from '@semapps/middlewares';
 
 function getCatchAllRoute(basePath: any, podProvider: any) {
-  const middlewares = [
+  let middlewares = [
     parseUrl,
     parseHeader,
     negotiateContentType,
@@ -25,6 +26,8 @@ function getCatchAllRoute(basePath: any, podProvider: any) {
     saveDatasetMeta
   ];
 
+  if (podProvider) middlewares.unshift(checkUsernameExists);
+
   return {
     name: 'ldp',
     path: path.join(basePath, podProvider ? '/:username([^/.][^/]+)/:slugParts*' : '/:slugParts([^/_][^/]+)*'),
diff --git a/src/middleware/packages/ldp/routes/getPodsRoute.ts b/src/middleware/packages/ldp/routes/getPodsRoute.ts
index 36874298c..b7a1b2585 100644
--- a/src/middleware/packages/ldp/routes/getPodsRoute.ts
+++ b/src/middleware/packages/ldp/routes/getPodsRoute.ts
@@ -9,7 +9,8 @@ import {
   parseJson,
   parseTurtle,
   parseFile,
-  saveDatasetMeta
+  saveDatasetMeta,
+  checkUsernameExists
 } from '@semapps/middlewares';
 
 const transformRouteParamsToSlugParts = (req: any, res: any, next: any) => {
@@ -26,7 +27,8 @@ const transformRouteParamsToSlugParts = (req: any, res: any, next: any) => {
 };
 
 function getPodsRoute(basePath: any) {
-  const middlewares = [
+  let middlewares = [
+    checkUsernameExists,
     parseUrl,
     parseHeader,
     negotiateContentType,
diff --git a/src/middleware/packages/middlewares/index.ts b/src/middleware/packages/middlewares/index.ts
index 0267cecbf..1d148e07a 100644
--- a/src/middleware/packages/middlewares/index.ts
+++ b/src/middleware/packages/middlewares/index.ts
@@ -49,7 +49,7 @@ const throw403 = (msg: string) => {
 };
 
 const throw404 = (msg: string) => {
-  throw new MoleculerError('Forbidden', 404, 'NOT_FOUND', { status: 'Not found', text: msg });
+  throw new MoleculerError('Not found', 404, 'NOT_FOUND', { status: 'Not found', text: msg });
 };
 
 const throw500 = (msg: string) => {
@@ -198,6 +198,23 @@ const saveDatasetMeta = (req: any, res: any, next: any) => {
   next();
 };
 
+// To be used with a pod provider setting
+const checkUsernameExists = async (req: any, res: any, next: any) => {
+  if (req.$params.username) {
+    const account = await req.$ctx.call('auth.account.findByUsername', { username: req.$params.username });
+    if (!account) {
+      res.statusCode = 404;
+      res.statusCode = `User ${req.$params.username} not found`;
+      res.end();
+    } else if (account.deletedAt) {
+      res.statusCode = 400;
+      res.statusCode = `User ${req.$params.username} has been deleted`;
+      res.end();
+    }
+  }
+  next();
+};
+
 export {
   parseUrl,
   parseHeader,
@@ -208,6 +225,7 @@ export {
   parseTurtle,
   parseFile,
   saveDatasetMeta,
+  checkUsernameExists,
   throw400,
   throw403,
   throw404,
diff --git a/src/middleware/packages/sparql-endpoint/getRoute.ts b/src/middleware/packages/sparql-endpoint/getRoute.ts
index 14b073919..9adcca504 100644
--- a/src/middleware/packages/sparql-endpoint/getRoute.ts
+++ b/src/middleware/packages/sparql-endpoint/getRoute.ts
@@ -1,7 +1,9 @@
-import { parseHeader, negotiateAccept, parseSparql, saveDatasetMeta } from '@semapps/middlewares';
-const middlewares = [parseHeader, parseSparql, negotiateAccept, saveDatasetMeta];
+import { parseHeader, negotiateAccept, parseSparql, saveDatasetMeta, checkUsernameExists } from '@semapps/middlewares';
+
+function getRoute(path: any, podProvider: boolean) {
+  const middlewares = [parseHeader, parseSparql, negotiateAccept, saveDatasetMeta];
+  if (podProvider) middlewares.unshift(checkUsernameExists);
 
-function getRoute(path: any) {
   return {
     path,
     name: 'sparql-endpoint',
diff --git a/src/middleware/packages/sparql-endpoint/service.ts b/src/middleware/packages/sparql-endpoint/service.ts
index 74851cc2e..578b940ff 100644
--- a/src/middleware/packages/sparql-endpoint/service.ts
+++ b/src/middleware/packages/sparql-endpoint/service.ts
@@ -15,11 +15,14 @@ const SparqlEndpointService = {
     const basePath = await this.broker.call('ldp.getBasePath');
     if (this.settings.podProvider) {
       await this.broker.call('api.addRoute', {
-        route: getRoute(path.join(basePath, '/:username([^/.][^/]+)/sparql')),
+        route: getRoute(path.join(basePath, '/:username([^/.][^/]+)/sparql'), this.settings.podProvider),
         toBottom: false
       });
     } else {
-      await this.broker.call('api.addRoute', { route: getRoute(path.join(basePath, '/sparql')), toBottom: false });
+      await this.broker.call('api.addRoute', {
+        route: getRoute(path.join(basePath, '/sparql'), this.settings.podProvider),
+        toBottom: false
+      });
     }
   },
   actions: {