Disable “call forwarding active” popup on iPhone

After I changed my Service Provider from Telia (Denmark) to Telmore (Demark), a little popup is shown – “Call Forwarding Active” each I make a call. This is quite annoying… an easy way to remove this is by using GSM codes:

Your phone will now show this:

This could remove your voicemail configuration, using Telmore it is reenabled by this:

Additional Codes:

Unconditional forwarding:

Forward service: All Calls
Activate: *21*phone_number#
Cancel & Deregister: ##21#
Cancel & Retain: #21#
Status: *#21#
Reestablish: *21#

Conditional forwarding:

Forward service: If Busy
Activate: *67*phone_number#
Cancel & Deregister: ##67#
Cancel & Retain: #67#
Status: *#67#
Reestablish: *67#

Forward service: If Not Answered
Activate: *61*phone_number#
Cancel & Deregister: ##61#
Cancel & Retain: #61#
Status: *#61#
Reestablish: *61#

Forward service: If Out of Reach
Activate: *62*phone_number#
Cancel & Deregister: ##62#
Cancel & Retain: #62#
Status: *#62#
Reestablish: *62#

Simultaneous forwarding:

Forward service: All Forwards
Activate: *002*phone_number#
Cancel & Deregister: ##002#
Cancel & Retain: #002#
Status: *#002#
Reestablish: *002#

Forward service: All Conditional Forwards
Activate: *004*phone_number#
Cancel & Deregister: ##004#
Cancel & Retain: #004#
Status: *#004#
Reestablish: *004#

More GSM codes…