Carrier Lock vs Network Lock: What's the Difference?

The terms carrier lock and network lock are often used interchangeably, but they can describe different layers of restriction.

Carrier lock

A carrier-locked phone is tied to a specific mobile network, usually because it was sold on a contract or installment plan. It will not accept SIM cards from other carriers until the lock is removed or the contract is fulfilled.

Network lock

Network lock is sometimes used to mean the same thing, but can also refer to a regional or technical restriction. In most used-phone listings, "network locked" simply means the device is limited to one carrier or group of carriers.

How to check either one

The iPhone Network Lock Check and the iPhone Carrier & SIM-Lock Check both report whether the device is restricted and which carrier it is tied to.

Bottom line

For buyers, the practical difference is small: any lock means the phone may not work with your SIM. Always verify the status before buying.