Iphone 4- will a tmobile sim work in any iphone 4?

Iphone 4- will a tmobile sim work in any iphone 4?

If the phone is either locked to t mobile or is unlocked which basically means that any sim works in it.

if your phone is locked to another network you can get it unlocked at most phone fixing shops for only a few £'s.Typically less than £5 but sometimes up to £10