Buying on Craigslist

The non legal answer. Its probably fine for T Mobile's network, just not one they sell. Its likely an "unlocked" " phone used on a competitor's network. You may only need to buy a battery. Legal answer is this may be a civil or criminal offense. Practically speaking, unless the phone is also stolen, its very unlikely a prosecutor or police will want to investigate this as a fraudulent criminal act. This is too bad because they can use their investigative and subpoena powers to investigate the originator of the craigslist posting. As a civil case, you are likely out of luck. If you can locate the seller, you may technically have a fraud claim depending on what representations seller made to you. You may also have common law ands contract claims based on the Uniform Commercial Code. That is, that the phone is what was represented by the seller to be, that it works as represented, and that seller was the actual owner and had right to sell . If your state has a streamlined small claims court, and if you can get a good identification and location of the seller, you could attempt to sue him in small claims court without a lawyer. This would be your most economical way to handle this loss.