Apple is poised to start offering an in-store trade-in program, but consumers already have plenty of options to turn their old iPhone into cash—enough, in some cases, to get their next one for free.

The company launched the new program on Friday, offering a credit for returned iPhones that can be used toward the purchase of a new one. That's just in time for Apple's Sept. 10 event where analysts expect the company to announce a new iPhone.