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As an Etisalat Subscriber, you can share and transfer airtime credit with other subscribers. This service is called Credit Transfer. The following tutorial will show two ways of accomplishing this.

Option 1. Transfer credit using the Service Menu: Etisalat Nigeria's Service Menu can be accessed by dialling *200# and you get many options, number one of which is My Account. Respond with option 1 to select this option and you get many sub-options, number 4 of which is Credit Transfer.
Respond with 4 to select this option. The last instruction will say:
1. To transfer credit: Enter
1*pin*amount*PhoneNo#

And... that's it.
Note: If you are transferring credit for the first time, your default pin is 0000. You can change your pin via the service menu if you wish.

Option 2. The alternative modus operandi is by dialling *223*Pin*Amount*Phone Number# directly on your line.

continue: http://www.techmej.com/2016/11/how-to-transfer-airtime-credit-from.html