UK Platform: End Call Reason Destination: Error (503 or Fast Busy) - Invoca

This end of call reason usually means the destination carrier rejected the call due to their own settings.

Applies to

UK calls
Destination error
Call routing issues
Anonymous Caller ID

Answer

If a call’s End of Call Reason shows Destination: Error (503 or Fast Busy), the call is being rejected at the destination carrier — usually due to settings on the carrier’s end, not your Invoca configuration.

Where to go next

Last modified on September 29, 2026