Log onto the Nigeria Immigration Service website (see Resources) and complete the Visa Application Form online. Print it out to be mailed along with other necessary travel documents.
Continue to the Payments section and make the online payment once your application is complete. Print out the confirmation page and attach it to your application.
Include your current passport with a remaining validity of at least six months. Also provide two professional passport photos taken by a local passport facility.
Obtain a letter of invitation from your Nigerian host, such as a friend or relative. A confirmed hotel reservation is also valid.
Provide a photocopy of your green card if you are not a U.S. citizen. This confirms your legal residency.
Gather your application and documents and prepare them for mailing. The Embassy of the Federal Republic of Nigeria requires that you also include a similar return envelope and stamp. Address your package to 3519 International Court, NW in Washington, DC 20008.