Phone-locking can be confusing, but it doesn't need to be. These five steps will carry you through almost any situation you find yourself in when it comes to how to unlock your cellphone.
Verify that it is locked. Retrieve the IMEI number by dialing *#06# and then enter the number into any of the free IMEI check websites online. It may not even be locked. If it is Verizon phone, for example, then it is probably already unlocked. Most other carriers lock their phones during the payoff period. But they don't necessarily unlock the phone once it is paid off.
If it is indeed locked, then you must determine whether or not it is eligible for unlocking. Go to your carrier's website and research the rules for unlocking. Usually, this means paying off the phone. If the phone is not paid off, no carrier will unlock it.
If it is elible for unlocking, then contact your carrier by phone. Depending on the carrier, this can take from minutes to hours to days. If the phone is AT&T, it is a very simple matter to unlock it from their online, unlock portal at: https://www.att.com/deviceunlock/#/unlockstep1
If you bought a locked phone from a third-party and it is not paid off, then it is permanently locked to that carrier. Even if it is paid off, if you bought it from a third-party there is no way to permanently unlock the phone from their network - except in the case of AT&T. Its unlock portal does not require that you be a present customer to unlock the phone. True, there are third-party unlock services, but there are risks and limitations in a constantly evolving environment of rules and software updates. It may work for a while, but then one day a software update can cause it to relock without warning.
Test the unlock by inserting a SIM card from another carrier. If it finds a signal and makes a test call, then you are unlocked. In the US, there are two types of phones GSM and CDMA. If the phone was originally on AT&T or T-Mobile, then it may not work on Verizon or Sprint even if it is unlocked. Verizon and Sprint phones will work on all US-based carriers.
See? That wasn't so hard, was it?
Blue Blazer Wireless
Sell your phone in minutes