When you change your sim card they do not always come with your phone number programmed and unless you know how to set this it can feel like dark magic.
Via Cyanogenmod 12
- Open the phone dialer
- Navigate to Settings/Calls/Additional settings/My Phone Number
- now enter you phone number and save.
You can now check your phone numebr has been set by going to settings/About Phone/Status/SIM Status/My Phone Number
Links
- How to add your mobile number to your phone - The giffgaff community- List of phones capable of manually entering the number correctly
- Setting “My Phone Number” (MSISDN) via Android | Random Nothings