How do i get my t-mobile sim card to work for At&t iphone?

[Laura]

I got my moms old iphone but she had at&t and i have t-mobile. How do i get my t-mobile sim card to work for it?

 

[Unregistered]

i just by unlocking your iphone from AT&T network lock you can freely use it with your t-mobile sim card ..You can easily unlock your iphone from AT&T network lock with the help of sites like Unlocking4u.com here they will unlock your iphone using remote unlocking service for affordable cost .....