No cellular service after new sim.
Bought used iPhone 7. Put in new Sim and powered up. The phone showed name of carrier top left. Phone showed cellular network service.
Unable to call, text, internet.
iPhone 7
Question marked as
It sounds like that device is locked to a specific carrier. Should be this case, neither we (just users like you) nor Apple can help you. Only the carrier that iPhone is locked to can unlock it, if you are eligible.
See this support article:--> How to unlock your iPhone for use with a different carrier – Apple Support
Regards
Giulio