T-Mobile provides several options to get value from your old device, primarily in the form of bill credits rather than direct cash. Promotional Trade-In | T-Mobile Support
as a standalone brand no longer exists following its 2020 merger with T-Mobile , and its operations were fully migrated by the summer of 2023. Consequently, any requests to "sell" or trade in an old phone are now handled through T-Mobile's official channels and systems. Current Trade-In Programs (Via T-Mobile) will sprint buy my old phone