Bvn stands for bank verification code , its very important and its already mandatory that every Nigerian bank account must have one. well I did mine but lost it when my mobile phone was formatted when it developed a little problem and I lost the code that I saved there . some Nigerians are in dilemma like this but if you have lost your bvn code there is no need to worry . just dial 5650# to get your code back. they will cut about #10 to #15 of your mobile airtime for the service.