The network lock is a type of lock used by network providers (like Vodafone, AT&T etc) to restrict the use of phones only to their network. So, you are not able to use a SIM card from a different carrier (in your country or when traveling abroad). When trying to use a SIM card from a different carrier your phone will require a network unlock code.
The easiest way to check if your phone is network locked is by inserting a SIM card from a carrier different than the carrier you originally bought your phone from. If your phone reads one of the following messages, then it’s network locked:
- “SIM Network Unlock PIN”
- “Enter Network Lock Control Key”
- “Network Locked”
Another method to check if your Samsung is network locked is by dialing *#7465625#. A menu will be displayed that will resemble the following:
[ ] Network lock
[ ] Subset lock
[ ] SP lock
If all lock levels on this menu are OFF, then your phone is unlocked. If Network Lock is ON then your phone is network locked. If Subset lock is ON then your phone needs a provider unlock code. If SP lock is ON then your Samsung needs a service provider unlock code. We will provide you all these unlock codes.
Unfortunately, this method (*#7465625#) does not work on all Samsung phones. It actually depends on the Android version you have installed on your phone. For some Android versions, when dialing *#7465625# you’ll only get the message “Connection problem or invalid MMI code”.