Warning: Do not enter any wrong unlock unlock codes on your ZTE GR231 mobile phones. If you enter over a certain amount of wrong unlock codes on your mobile phone, your phone may get hard locked and sometimes become unusable.Method-1:
1 - Switch ON your ZTE GR231 with a NOT ACCEPTED* SIM Card,
2 - Phone will prompt for Unlock Code (NP Code),
3 - Enter the Unlock Code you received.
OR(If the method-1 does not worked)
Method-2:
1 - Remove the SIM card and compose the code
###825*09#,
2 - Phone will prompt for Unlock Code (NP Code),
3 - Enter the Unlock Code you received.
4 - Failed above, try
*983*8284# to access the Unlock Menu,
5 - Failed above, finally try
*983*865625# to access the Unlock Menu.
*NOT ACCEPTED : We mean, to use a sim card from a network other than the network your ZTE GR231 is locked to.
Each ZTE GR231 mobile phone has an unique unlock code. You can buy the unique unlock code for your ZTE GR231 mobile phone at www.mobileunlocksolutions.com.