Strange call forwarding numbers NOT set by me

[Colin]

The following call forwarding numbers have been set, but not by me:-

Forward When busy: +447802091906

Forward When unanswered: +447802091910

Does anyone have an explanation for this please?

[MI5]

They could be picked up off the SIM card or in the firmware of the phone.
There are often strange numbers found on phones unlocked from other networks.

[Anonymous]

@Colin Cancel all diverts using ##002#

[jonsie]

If you have ever swapped sim or been allocated a temporary number by changing networks then yes, it's possible that this could have happened. It's not uncommon and certainly nothing to worry about and certainly not suspicious. As advised, just cancel all diverts and if you want call forwarding then insert the correct number. Otherwise enter 901 as the forwarding number which is the default voicemail number.

[Colin · Accepted solution]

MYSTERY SOLVED

The network sets these call forwarding numbers when you activate Call Alert by dialling 1710. Each divert says "The person you are phoning can't take your call. We will send your number by text to let them know you have called."

[MI5]

So picked up off the SIM card then as I suggested.