i have looked on the att website and in attendance is no help to be found on the topic.
Answers: Yeap you can port your number to any cell phone service company. Remember until that time you port your number to a new cell phone company do not telephone call your old cell phone company and convey them that you are cancelling or porting your phone number to another company. If you do this, you will lose you phone number.
The cell phone company that you are moving to will automatically port your cell phone number and will retract your account beside your previous cell phone provider. Just visit any of the retail stores resembling AT&T and a sales rep will automatically port your phone number to their service.
Make sure that you do not own any oustanding bills and that your contract with your ripened cell phone company has done or else you will return with a huge bill in the correspondence from them when you moved to new cell phone company.