How to unlock an att iphone 4s?

So i bought an iphone 4s at gamestop and it was an att phone{i'm with t-mobile} , the guy who sold me the phone said that even though its an att phone it can still be activated to my service but today i went to t-mobile and they said i couldn't do it because i had to unlock my iphone first before i can connect it to t-mobile. I know what i got to do but will i have to pay to unlock it?

Go to shop

AT&T *might* unlock it for free. Anyone else would charge you.

AT&T might unlock it for free but if they don't you may have to take active it as a go phone with them for up to 6 months in order to meet the requirements otherwise

AT&T's requirements of unlocking tablets and phones
https://www.att.com/...ent/en_US/

  • Would att unlock my iphone 4? I have an iPhone 4 which was unlocked by att through their program. They unlock a phone when it fulfilled its contract with them.either being with them two years or having paid early termination fees. but there's something wrong with my phone.apple will give me a new iPhone for $149 but they told me it would be locked with att. Now my question is would att unlock the new phone for me?
  • What do i need to do to unlock an att iphone 4? So i bought an iphone 4 on ebay and i wanted to know what i need to do to unlock it does it need to be in service?
  • I got a 2nd hand att iphone 6 plus i took it to att to activate? But the phone had been reported stolen/lost. The guy i bought it off from is not answering so he will not give me the money back. Can i use it with another carrier? Or what can i do to use it? Its unlock already.
  • How to unlock sprint iphone 5 for att? I was given a Sprint iPhone 5 but my cell carrier is ATT. How do I unlock the phone to be compatible with ATT. Called sprint but they said they don't condone unlocking so they were no help.