What is an Alien Number?

An Alien Number (or A-Number) is an identification number issued to non-U.S. citizens by the U.S. government. It typically begins with the letter ‘A’ followed by 8 or 9 numbers. This number is found on green cards, employment authorization documents, certain approval notices, and may also be listed as a “USCIS number.” If you have not been issued any of these documents, you may not have an Alien Number.