A USCIS A-Number, short for Alien Registration Number, is the unique identifier the Department of Homeland Security assigns to a non-citizen and keeps attached to that person for life. It consists of seven, eight, or nine digits preceded by the letter “A,” and it ties together every immigration record USCIS holds on you.1U.S. Citizenship and Immigration Services. A-Number/Alien Registration Number/Alien Number You’ll find it printed on your green card, your Employment Authorization Document, your immigrant visa stamp, and most notices USCIS mails you.
What the A-Number Is
The A-Number is a personal identifier, not a case number. Once DHS assigns it, the number stays with you permanently. If you adjust status, renew a green card, apply for naturalization, or file any other benefit years later, USCIS pulls your history through the same number. Your individual immigration file, called an A-File, is organized under it.2U.S. Citizenship and Immigration Services. A-Files Numbered Below 8 Million – Section: What Are A-Files?
Older records use seven- or eight-digit A-Numbers. Current assignments are nine digits. This matters when you’re filling out forms. If a form asks for nine digits and yours is shorter, add leading zeros after the “A” to pad it out. For example, A12345678 becomes A012345678.3U.S. Citizenship and Immigration Services. Immigrant Fee Payment: Tips on Finding Your A-Number and DOS Case ID
The government has been issuing A-Numbers since 1940 under the original Alien Registration Program, and A-Files have been organized by A-Number since 1944.2U.S. Citizenship and Immigration Services. A-Files Numbered Below 8 Million – Section: What Are A-Files?
Who Gets an A-Number
Permanent residents, people in removal proceedings, and applicants for certain immigration benefits all receive A-Numbers. Most non-citizens present in the U.S. temporarily on visitor or business visas do not.
One exception surprises people. F-1 students who receive work authorization, particularly through Optional Practical Training, are assigned an A-Number even though they never applied for a green card. If you worked under OPT at any point, you may already have one and not realize it. Check your old EAD.
USCIS Number vs. A-Number: The Same Thing
Green cards issued after May 10, 2010, print the label “USCIS Number” on the front instead of “Alien Registration Number.” Despite the different label, it is the same nine-digit number.4U.S. Citizenship and Immigration Services. USCIS Number If a form asks for your A-Number and your card only shows “USCIS Number,” use that. They’re interchangeable.
Where to Find Your A-Number
Your A-Number appears on several documents, so before assuming you don’t have one, check all of them.
Permanent Resident Card (Green Card)
The A-Number is printed on the front of your green card, labeled either “Alien Registration Number” on older cards or “USCIS Number” on cards issued after May 2010.4U.S. Citizenship and Immigration Services. USCIS Number
Employment Authorization Document (EAD)
Your EAD carries the A-Number as a nine-digit number on the card itself.5FBI. NICS: Where to Locate Alien Numbers ATF Form 4473 This is often the first place OPT participants and other work-authorized non-citizens see their number.
Immigrant Visa Stamp
If you entered the U.S. on an immigrant visa, the A-Number is printed on the visa stamp in your passport under the label “Registration Number.”3U.S. Citizenship and Immigration Services. Immigrant Fee Payment: Tips on Finding Your A-Number and DOS Case ID
Form I-797 Notices of Action
USCIS notices about your case often print the A-Number alongside your name and receipt information. If you’ve filed anything with USCIS and received a notice back, look there.
How to Recover a Lost A-Number
Because the A-Number appears on multiple documents, losing one item rarely means the number is gone. Check every immigration document you have before assuming you need to recover it. Old EADs, expired green cards, and passport visa stamps all keep the number readable.
If you genuinely can’t find it anywhere, you can request your own immigration records through a Freedom of Information Act or Privacy Act request. As of January 2026, USCIS requires these requests to be submitted online at first.uscis.gov after creating an account.6U.S. Citizenship and Immigration Services. Request Records through the Freedom of Information Act or Privacy Act Be specific about what you want. Asking for a single document that shows your A-Number moves faster than requesting your complete A-File.
Keeping Your A-Number Safe
Your A-Number is classified as Personally Identifiable Information under the Privacy Act, and USCIS treats it accordingly.7U.S. Citizenship and Immigration Services. Chapter 7 – Privacy and Confidentiality Someone with your A-Number and a few other personal details could impersonate you in communications with USCIS or use the information in identity fraud.
USCIS itself uses the number as a verification layer. When you call about a case, an agent will ask for your A-Number, receipt number, full name, and date of birth before discussing any details. If the caller can’t provide information the applicant would reasonably know, the agent can refuse to answer.7U.S. Citizenship and Immigration Services. Chapter 7 – Privacy and Confidentiality That protection only works if the number hasn’t already leaked. Don’t post it on public forums, and redact your A-Number before sharing photos of immigration documents.
Don’t Confuse the A-Number With Other USCIS Numbers
Two other identifiers get mistaken for the A-Number, and using the wrong one on a form or in a status check will stall you.
A Receipt Number is a 13-character identifier (three letters followed by ten digits) that USCIS generates for each application or petition, printed at the top of your Form I-797 Notice of Action.8U.S. Citizenship and Immigration Services. Receipt Number It tracks one case. File something new next year and you get a new receipt number. Your A-Number does not change.
A USCIS Online Account Number is a separate 12-digit identifier assigned when you create an online account at my.uscis.gov. It links your digital profile to cases you manage online. If you’ve never created an account, you don’t have one, and leaving that field blank on a form is fine.
Your A-Number identifies you. The other two identify a case or an account.