My mother never memorizes her cell phone number, so on her current phone, she always goes through a quick menu to display her phone number to give out to others. I’m not quite sure why she hasn’t just memorized her phone number yet, but it you are like her, and own an iPhone, you may have a problem looking at your own number.
Generally, the subscriber’s own number is displayed at the top of the contacts list (above the search function). The simple answer to this issue: the number was never properly saved to the iPhone’s SIM card.
This problem can be solved in one of three ways:
-Insert the SIM card in another phone that allows you to manipulate SIM card contacts directly and enter your number.
-Call AT&T customer support at 1-800-331-0500, explain the issue, and ask them to send you an over-the-air SIM update with your number.
-Go to an AT&T store and ask them to program your SIM card appropriately.
Seems like a lot of trouble for those like myself who don’t really need to reference their phone number. Nevertheless, the option is there so you’ll never forget again. Source...