Many communication networks are doing good by bringing innovation into their operations for customers to enjoy. One of them is transferring airtime(credit) from one to another phone.Many of  customers are abusing this innovation they intentionally transfer one’s credit to their phone without the owner’s knowledge. I am here to show you how to lock your airtime if you don’t want your friend to use your credits for calls and to generate a personalized code for locking your airtime both MTN and AIRTEL Networks.                                   HOW DO I LOCK MY AIRTIME (CREDIT)
1. Dial *33*0000#2. Press okay         Your credit will be locked and thus no one can make calls or send sms with your phone                  

                                 HOW TO UNLOCK YOUR AIRTIME (CREDIT)1. Dial #33*0000#

                    HOW TO PERSONALIZE YOUR AIRTIME LOCKING CODEThis will show you how you can personalize your code to change from 0000 to your choice of lock digits follow the below steps to get your own secret code for unlocking your airtime.
1. Dial **33*330*0000* your new secret pin in four digit* 2. Repeat your new secret pin in four digit#                          Example: **33*330*0000*3450*3450#                            3450 is your new pin, Lock your airtime you press *33*3450#To unlock your airtime dial #33*3450#