1. Access: *901*911#
2. Zenith: *966*911#
3. GTB: *737*51*74#
4. WEMA: *945*911#
5. FirstBank: *894*911#
6. Keystone: *7111*911#
7. UBA: *919*911#
8. FCMB: *329*911#
9. Sterling Bank: *822*911#
10. Unity Bank: *7799*911#
11. Fidelity Bank: *770*911#
12. Heritage Bank: *745*7#
I3. Ecobank *326*911#
14. Union Bank *826*911#
15. Stanbic *909*911#
16. Polaris Bank *833*911#
Dial the code from any line, you will be asked to enter the number you want to deactivate, and that settles it.