What is an Alien Registration Number (A-Number)?

Who Receives an Alien Registration Number?

Not every visitor to the U.S. will receive an Alien Registration Number. A-Numbers are issued to immigrants who apply for long-term residency or plan to stay permanently. This includes people applying for a green card, family-sponsored visas, or other long-term immigration benefits. Refugees, asylees, and others seeking humanitarian relief also receive A-Numbers.

Are temporary visa holders eligible for an Alien Registration Number?

However, if you’re in the U.S. temporarily on a tourist or business visa, you likely won’t have an A-Number, as you aren’t intending to become a permanent resident. 

That said, there’s an exception: some temporary visa holders, like F-1 students applying for employment authorization under the Optional Practical Training (OPT) program, may receive an A-Number.

Where Can I Find My Alien Registration Number?

So, you know you have an A-Number, but where exactly can you find it? Luckily, it’s prominently displayed on several key immigration documents. Let’s walk through the most common places to look:

• Employment Authorization Document (EAD): Commonly known as a work permit, your A-Number is usually listed below the "USCIS#" on your card.
• Permanent Resident Green Card: If your green card was issued after May 10, 2010, your A-Number will be listed as your USCIS#. For older cards, it may appear in a different spot.
• Immigrant Visa: If you don’t have a green card yet, your A-Number can be found on your immigrant visa stamp, just below the “Registration Number” field.
• USCIS Notices: Any official correspondence from USCIS, like your Notice of Action (Form I-797C), will usually have your A-Number at the top.

What if I can’t find my A-Number?

Don’t worry, if you’ve applied for immigration benefits before, it’s bound to be on one of these documents. 

A-Numbers vs. USCIS Case Numbers

It’s easy to confuse your A-Number with your USCIS case number since both are listed on your immigration paperwork. However, they serve different purposes. Your A-Number is your personal identification number and stays with you forever. 

On the other hand, your USCIS case number is specific to a single application. If you apply for a green card now and citizenship later, the two applications will have different case numbers, but the same A-Number.

Think of it this way: your A-Number is like your immigration fingerprint—unique and constant. Your case numbers, however, will change with each new application. For more detailed definitions of these terms, check out our immigration legal glossary.

What to Do if You Lose Your A-Number

Fortunately, there’s a process to retrieve your A-Number if you misplaced it. You can submit a Freedom of Information Act (FOIA) request to USCIS to obtain a copy of your immigration file, which will include your A-Number. 

Additionally, you can schedule an appointment with a local USCIS office or seek help from an immigration attorney.