Can you switch an iphones carrier?

I found an iphone last week, and its carrier is AT&T. But my current one is T-Mobile. Can you switch it to t-mobile?

The previous owner of the iphone may already have reported it missing, so the phone may be locked and unusable.

No stick with at&t, trust me, trying to get out of my tmobile plan, even the jump program it's tricky, the network isn't as good either

Are you serious? Someone is probably very upset they lost that phone. How could you keep it? Go into the phones contacts and call someone. Look for "home" or "mom" or someone that you can call to let them know you found this persons phone. What you're doing is wrong and karma will get you.

You will not be able to activate that phone on your own account, because the smart former owner will have reported it lost or stolen, and now that phone is blacklisted. You found a paperweight that looks like an iPhone.

Now you can take it to the nearest AT&T store and they will get in touch with the owner and he or she can if they feel like it, unblacklist the phone, so you can use it, but I don't know too many people that would do that, even if they got a replacement, especially if it had been stolen, before you got your hot little hands on it.

You can unlock the phone and use it on T-Mobile. If you need help with factory unlocking the AT&T phone, mail me.