diff --git a/app/device_manager.py b/app/device_manager.py
index a7acb07..adb78d1 100644
--- a/app/device_manager.py
+++ b/app/device_manager.py
@@ -827,14 +827,15 @@ class DeviceManager:
             return {'success': False, 'error': 'Device not connected'}
 
         try:
-            # Find contact dict from mc.contacts (used for retry/path info)
-            # send_msg() also accepts a hex pubkey string directly
+            # Find contact in device's contact table
             contact = self.mc.contacts.get(recipient_pubkey)
             if not contact:
                 contact = self.mc.get_contact_by_key_prefix(recipient_pubkey)
             if not contact:
-                # Use pubkey string directly — meshcore lib handles it
-                contact = recipient_pubkey
+                # Contact must exist on device to send DM
+                return {'success': False,
+                        'error': f'Contact not on device. '
+                                 f'Re-add {recipient_pubkey[:12]}... via Contacts page.'}
 
             # Generate timestamp once — same for all retries (enables receiver dedup)
             timestamp = int(time.time())