iPhone Carrier & SIM-Lock Check: What It Means and How to Verify

"Carrier lock" and "SIM lock" describe the same thing: the phone is tied to one mobile network and will not accept a SIM from another carrier. Knowing the lock status before you buy saves you from a phone that only works on one expensive network.

Carrier lock vs SIM lock vs network lock

These terms are interchangeable in practice. A locked iPhone will reject a SIM from a different carrier and show a message like "SIM not supported." A factory-unlocked phone works on any compatible network worldwide.

Why the lock status matters

• Locked phones are worth less and are harder to resell.
• Travelers cannot use a local SIM abroad.
• Some carriers charge a fee (or require the original owner) to unlock.

How to verify the carrier and lock status

A carrier check identifies the original network the iPhone was sold on and whether it is locked or unlocked. Use the iPhone Carrier Check for the original carrier, or the iPhone Network Lock Check for a combined lock report.

Locked vs unlocked: which should you buy?

If the price is much lower than similar unlocked models, assume it is locked. Only buy a locked device if you plan to use it on that specific carrier and have confirmed the unlock policy.

Bottom line

Always confirm the lock status with a live lookup. A clean, unlocked phone is the only safe choice for resale and travel — verify it with the Full IMEI Check before you pay.