| Carrier Region | Code | Function | |---|---|---| | US (Landline/VoIP) | *69 | Dials the last incoming number, even if private (if supported). Does not display number but connects the call. | | UK / Europe | 1471 | Returns the last caller's number; private numbers may be announced as "number withheld." | | General GSM | #31# | Prefix to unblock your own ID, not to reveal a private caller. |
An Examination of Methods to Unblock a Private Call: Telecommunications and Smartphone Contexts how to unblock a private call