Users Of MTN sims who recharge their lines with N200 or more are normally credited with Bonus airtime of N200 whose validity spans till 11:59pm That same day. I've been getting the bonus airtime but haven't been using them until recently when i put a call through to an MTN Custormer Care agent who consequently said the following:

To add a number, Dial *380*1*MTN number#

To remove the number, Dial *380*2*MTN number#

NOTE:
1. You Can't remove a number until after 30days. However, if you want to remove the registered number and register a new one before the 30days is complete, N100 will be deducted.

2. MTN ipulse Subscribers are not eligible to register with this service (Reason: I asked the CC Agent and he simply said "That's how it was programmed"