diff --git a/backend/app.py b/backend/app.py
index 43ea8bd..702fbcc 100644
--- a/backend/app.py
+++ b/backend/app.py
@@ -77,7 +77,7 @@ async def find_guest(party: str, token: str) -> DBGuest:
 class Party(MongoModel):
     name: str
     created: datetime
-    allowed_extra: list[str]
+    allowed_extra: dict[str, int]
 
 
 async def find_party(name: str) -> Party:
@@ -88,7 +88,10 @@ async def find_party(name: str) -> Party:
 
 
 def validate_extra(extra: dict[str, str], party: Party):
-    return all(k in party.allowed_extra and len(v) <= 64 for (k, v) in extra.items())
+    return all(
+        k in party.allowed_extra and len(v) <= party.allowed_extra[k]
+        for (k, v) in extra.items()
+    )
 
 
 # Guest methods
@@ -188,7 +191,7 @@ async def list_parties(_=Depends(auth_admin)):
 
 class PartyCreate(BaseModel):
     name: str
-    allowed_extra: list[str] = []
+    allowed_extra: dict[str, int] = dict()
 
 
 @app.post(
@@ -269,7 +272,7 @@ async def create_new_guest(party: str, new_guest: GuestCreate, _=Depends(auth_ad
 
 @app.get(
     "/{admin_token}/{party}/userAllowedExtra",
-    response_model=list[str],
+    response_model=dict[str, int],
     responses=error_responses(401, 404),
     tags=["admin"],
 )
@@ -284,7 +287,9 @@ async def get_allowed_extra_keys(party: str, _=Depends(auth_admin)):
     responses=error_responses(401, 404),
     tags=["admin"],
 )
-async def modify_allowed_extra_keys(party: str, keys: list[str], _=Depends(auth_admin)):
+async def modify_allowed_extra_keys(
+    party: str, keys: dict[str, int], _=Depends(auth_admin)
+):
     party_obj = await find_party(party)
     party_dict = party_obj.dict(exclude={"id"})
     party_dict["allowed_extra"] = keys