Enable iPhone Voicemail Divert

After some further googling I have sorted this now. It appears that all UK T-Mobile users get an individual Voicemail divert number. Dialling 222 for the first time should have set this up for me but it didn't.

This worked for me:

• I completely reset all divert options by dialing ##004#
• I then re-dialled 222 and a message said that number had been set up and I need to reboot the phone.
• I also got an SMS with my voicemail divert number in it.
• I rebooted my phone and sent **004*+[the number from my sms]#

My voicemail is now working as expected!

You could go to the settings app and turn on "Do Not Disturb" and see if the carrier would divert things once you don't pick up each call.

If so, you could then review the settings under Notifications to ensure you get calls from Favorites (or not) while the settings are in effect.

Most carriers also have a number you can call to configure call forwarding. On AT&T in the US, this used to work…

1. Dial *#67# to see which number is used to forward calls to voice mail
2. Dial *21*number# to forward all calls unconditionally
3. Dial ##002# to restore the normal incoming call behavior