diff --git a/backend_splatournament_manager/src/app.ts b/backend_splatournament_manager/src/app.ts
index e861029..6c9ea36 100644
--- a/backend_splatournament_manager/src/app.ts
+++ b/backend_splatournament_manager/src/app.ts
@@ -86,6 +86,9 @@ app.post('/teams', authMiddleware, async (req: Request, res: Response) => {
     if (!name || !tag) {
         return res.status(400).send({error: 'name and tag are required'});
     }
+    if (tag.length > 3) {
+        return res.status(400).send({error: 'tag must be at most 3 characters'});
+    }
     try {
         const team = await teamService.addTeam({name, tag, description: description ?? ''});
         // @ts-ignore
@@ -99,6 +102,10 @@ app.post('/teams', authMiddleware, async (req: Request, res: Response) => {
 });
 
 app.put('/teams/:id', authMiddleware, async (req: Request, res: Response) => {
+    const {tag} = req.body;
+    if (tag && tag.length > 3) {
+        return res.status(400).send({error: 'tag must be at most 3 characters'});
+    }
     try {
         await teamService.updateTeam(+req.params.id, req.body);
     } catch (err) {
diff --git a/docs/prompt.md b/docs/prompt.md
index 935917c..373c613 100644
--- a/docs/prompt.md
+++ b/docs/prompt.md
@@ -35,3 +35,8 @@ Folgende Dateien wurden in diesem Prompt verändert:
 Folgende Dateien wurden in diesem Prompt verändert:
     - frontend_splatournament_manager/lib/widgets/teams_list_widget.dart
     - frontend_splatournament_manager/lib/widgets/my_teams_widget.dart
+
+- Restrict team tags to at most 3 characters.<br><br>
+Folgende Dateien wurden in diesem Prompt verändert:
+    - backend_splatournament_manager/src/app.ts
+    - frontend_splatournament_manager/lib/pages/create_team_page.dart
diff --git a/frontend_splatournament_manager/lib/pages/create_team_page.dart b/frontend_splatournament_manager/lib/pages/create_team_page.dart
index 47e3f71..92feacd 100644
--- a/frontend_splatournament_manager/lib/pages/create_team_page.dart
+++ b/frontend_splatournament_manager/lib/pages/create_team_page.dart
@@ -109,14 +109,17 @@ class _CreateTeamPageState extends State<CreateTeamPage> {
                 controller: _tagController,
                 decoration: const InputDecoration(
                   labelText: 'Team Tag',
-                  hintText: 'Enter team tag (e.g., ABC)',
+                  hintText: 'Enter team tag (max 3 characters)',
                 ),
-                maxLength: 5,
+                maxLength: 3,
                 textCapitalization: TextCapitalization.characters,
                 validator: (value) {
                   if (value == null || value.isEmpty) {
                     return 'Team tag is required';
                   }
+                  if (value.length > 3) {
+                    return 'Tag must be at most 3 characters';
+                  }
                   return null;
                 },
               ),