diff --git a/app/main.py b/app/main.py
index abbf3f0..5d47d31 100644
--- a/app/main.py
+++ b/app/main.py
@@ -2042,17 +2042,18 @@ def _verify_broker_secret(request: Request) -> str:
 
 
 def resolve_member_email(identity: str) -> str:
-    """Resolve a member identity (email OR Cloudron username) to their email.
+    """Resolve a member identity (email, Cloudron username, or uid) to email.
 
-    If it looks like an email (contains "@"), return it lowercased. Otherwise
-    treat it as a Cloudron username and look up the corresponding email from
-    the Cloudron user list (synchronous, using urllib since this runs outside
-    the async request path of httpx).
+    Cloudron's OIDC `sub` claim is the user ID (uid-…), and email-invited users
+    have no username at all. So accept three identity shapes:
+    - email ("@") → return as-is
+    - uid-… → match on the user id
+    - username → match on the username field (legacy accounts)
     """
     identity = identity.strip()
     if "@" in identity:
         return identity.lower()
-    # Username → email via Cloudron user list.
+    # uid / username → email via Cloudron user list (one fetch covers both).
     import urllib.request
 
     req = urllib.request.Request(
@@ -2062,6 +2063,9 @@ def resolve_member_email(identity: str) -> str:
     with urllib.request.urlopen(req, timeout=15) as r:
         data = json.loads(r.read().decode())
     users = data.get("users", [])
+    for u in users:
+        if u.get("id") == identity:
+            return (u.get("email") or "").lower()
     for u in users:
         if u.get("username") == identity:
             return (u.get("email") or "").lower()