Nigeria Visa Validity:

The Nigerian tourist or business visa is typically issued for entry within ninety days of the date of issue for stays of 7 to 90 days, as granted by the Embassy. The visit must be completed prior to the expiration date of the visa.

The multiple entry visa is valid six months for a stay of 7-90 days on per visit. If you are applying for a 6 month multiple entry visa you must write a brief letter requesting that the validity of your visa be issued for 6 months. There is no guarantee that the Embassy will honor the request. If the request is denied the Embassy will issue a 3 month multiple entry visa instead. Visa issuance is at the sole discretion of the Nigerian Embassy.