Is the used phone locked to AT&T? How to check
Updated November 3, 2026
A phone locked to AT&T only works with AT&T service. AT&T will remove the lock once its requirements are met, and AT&T says that request can come from someone without an AT&T account, as long as the phone qualifies. The catch is that the phone has to qualify, and that depends on the seller.
What AT&T requires
From AT&T's support page, an AT&T phone (regular monthly service) qualifies to have its lock removed when:
- It was bought more than 60 days ago and isn't active on another AT&T account.
- It's paid in full. The installment balance must be zero.
- It hasn't been reported lost or stolen or involved in fraud.
- For current AT&T customers, the bill isn't past due.
- AT&T Prepaid phones need 12 months of paid AT&T service, and also can't be active on another AT&T account or reported lost, stolen or involved in fraud.
How to tell if it's locked
- iPhone: Settings > General > About > Carrier Lock. AT&T says "SIM locked" means it's locked. "No SIM restrictions" means it isn't.
- Samsung released after September 1, 2025: Settings > Connections > More connection settings > Network lock status.
- Older Samsung phones: Settings > About phone > Software information > Service provider software version. AT&T explains how to read it on its support page.
- AT&T Prepaid with a SIM card: put in a non-AT&T SIM. A message that the SIM isn't compatible means it's still locked.
- Before you meet: LegitPhone's report shows the carrier lock for iPhones.
What an AT&T lock tells you
Because AT&T requires the phone to be paid in full, a locked AT&T phone may still have an installment balance. Ask the seller to show a zero device balance in their AT&T account before you pay. And because AT&T won't remove the lock from a phone reported lost or stolen, check the lost/stolen list too.
If you're on AT&T
An AT&T locked phone can work on your AT&T line, as long as it isn't reported lost or stolen and isn't active on someone else's AT&T account. Check before you pay.
Check the phone before you pay
One $1.99 report checks the lost/stolen list, iCloud (Find My), carrier lock and Samsung Knox Guard, with one plain answer. No account needed.
Check a phone for $1.99See a sample reportRelated guides
- Is the phone carrier locked? How to check before you buy
- Is the used phone locked to Verizon? How to check
- Is the used phone locked to T-Mobile? How to check