The United States Citizenship and Immigration Services (USCIS) assigns an Alien Registration Number to every immigrant. This important number is required on immigration paperwork and other official documents.
What is an Alien Registration Number or “A” number?
“A” number is short for Alien Registration Number. It is a unique seven-, eight- or nine-digit number assigned to a noncitizen. The 9-digit USCIS number listed on permanent resident green cards issued after May 10, 2010, is the same as the A-number. The A-number can also be found on the back of green cards.
Where can I find my Alien Registration Number?
A-numbers are generally listed on your immigration documents, such as an immigrant visa or permanent resident green card.
Permanent Resident Green Card
On green card issued after May 10, 2010, the A-number is the same as the USCIS number, found on the front of your green card.
Employment Authorization Document (Work Permit)
On Employment Authorization Documents (work permits) the A-number is the same as the USCIS number.
On Immigrant Visas, the A-number is listed as the “Registration Number” and can be found on the front of the card.