What Is an A-Number? A Simple Guide to Alien Registration

An A-number (alien registration number) is the unique visa and immigration ID number that USCIS uses to track your case history in the United States. If you're filling out an immigration form and reached a field asking for your "A-Number" or "Alien Registration Number," you're not alone in wondering what it is or where to find it. This guide covers who has an A-number, where to locate yours on common immigration documents, and what to do if you can't find it.

What is an A-number (alien registration number)?

An A-number, also called an alien registration number or alien number, is a unique 7-to-9-digit identification number that USCIS assigns to noncitizens in the United States. It's always preceded by the letter "A" and formatted like A012-345-678. USCIS uses this number to track your immigration case history, link your applications together, and maintain your records across every interaction you have with the immigration system.

You'll get assigned an A-number the first time you formally interact with USCIS or the immigration system. That could happen when your employer files a petition on your behalf, when you apply for an employment authorization document (EAD), when you file for adjustment of status, or even when you enter the country and Customs and Border Protection (CBP) creates a record for you.

Once assigned, it doesn't change. Whether you switch visa categories, renew your green card, or apply for naturalization 20 years later, the same A-number follows you through every step.

How to read and format your A-number

A-numbers follow a consistent format: the letter "A" followed by 7 to 9 digits, as defined by USCIS. Small differences in how they appear on forms like the I-485 or I-765 can cause confusion.

The standard format is a letter "A" followed by 7 to 9 digits, sometimes written with hyphens for readability (A012-345-678). The hyphens are formatting only. A012-345-678 and A012345678 are the same number.

Older A-numbers may be 7 or 8 digits instead of 9. When a form requires 9 digits, pad with leading zeros after the "A." For example, A1234567 becomes A001234567.

Most USCIS forms want digits only in the entry field, not the letter "A." The form instructions will specify whether to include the letter or just the numbers. When in doubt, check the form's specific instructions for the A-number field.

Who has an A-number?

Whether you have an A-number depends on how you have interacted with USCIS. Green card holders and EAD holders always have one, while H-1B and E-3 visa holders may or may not. The table below shows which immigration statuses typically come with an A-number and which ones don't.

Not every noncitizen in the U.S. has an A-number. You'll have one if you've filed certain applications with USCIS or if the immigration system has created a record for you. Here's a breakdown by immigration status.

If you have previously applied for any U.S. immigration benefit, even if the application was denied, you may have been assigned an A-number. USCIS assigns the number when it processes the application, regardless of the outcome.

If you've never filed anything with USCIS and you're in the U.S. on a nonimmigrant visa without any pending applications, you probably don't have an A-number yet. You'll be assigned one when you first file with USCIS.

A-numbers for E-3 visa holders

First-time E-3 visa holders who went through consular processing only (the standard route for Australians) may not have an A-number. The E-3 consular process doesn't involve USCIS, so no A-number gets assigned during that step. You'll receive one when you first file directly with USCIS, such as an I-129 change of employer petition, an I-485 adjustment of status, or an EAD application. The same applies to H-1B1 holders from Singapore and Chile who processed through a consulate.

Where to find your A-number

Your A-number appears on several immigration documents you may already have. The tricky part is that it isn't always labeled "A-Number." On newer documents, USCIS uses the label "USCIS#" instead, which is the same thing.

Here's where to look on each document.

On your green card

Your green card is the easiest place to find your A-number. On the front of the card, look for the field labeled "USCIS#" followed by a 7-to-9-digit number. That's your A-number. On older green cards (issued before 2010), it may be labeled differently, but it's still on the front. Your A-number also appears on the back of the green card, directly before the 13-digit green card receipt number.

On your EAD card

The EAD card follows the same format as the green card. The number labeled "USCIS#" on the front of your EAD is your A-number. If you've had multiple EAD cards, the A-number on each one should be identical because it doesn't change.

On your I-797 approval notice

If USCIS approved a petition or application on your behalf, they sent you an I-797 notice of action. Your A-number appears near the top of the notice, typically next to your name or case information. It's usually labeled "A#" or "Alien Registration Number."

In your myUSCIS online account

If you've created an account at myUSCIS, your A-number is accessible through your profile and case details. Log in and navigate to your case overview. This is especially helpful if you don't have a physical document handy.

On your visa stamp

Whether your visa stamp includes your A-number depends on the type of visa. Immigrant visa stamps (the visa foil placed in your passport after consular processing for a green card) do include your A-number, listed as "Registration Number" in the top right portion of the stamp. If your A-number on the stamp is fewer than 9 digits, add a leading zero after the "A" to create a 9-digit number.

Nonimmigrant visa stamps (H-1B, E-3, F-1, B-1/B-2, etc.) do not include your A-number. These stamps are issued by the State Department and use different identifying information. If you're on a nonimmigrant visa, check your green card, EAD, I-797, or myUSCIS account instead.

On your immigrant data summary and USCIS Immigrant Fee handout

If you received your green card through consular processing, your A-number and DOS Case ID appear on two documents from your visa interview at the U.S. embassy or consulate. The immigrant data summary is stapled to the front of the immigrant visa package you received at the interview, with your A-number and DOS Case ID printed at the top. The USCIS Immigrant Fee handout, given to you by the interviewing officer, also includes both numbers in the top right corner. If you didn't receive either document, contact the U.S. embassy or consulate that issued your visa to request a copy.

A-number vs. USCIS number vs. receipt number: what's the difference?

USCIS forms ask for several different numbers that look similar but track completely different things. Mixing them up is one of the most common filing mistakes, and it can delay your case.

The most common confusion is between the A-number and the USCIS number. They're the same thing. USCIS started using the label "USCIS#" on newer green cards and EADs instead of "A#," but the number itself is identical. If a form asks for your "USCIS Online Account Number," that's a different number specific to your myUSCIS account.

The receipt number is entirely different. Every time you file a new application (I-485, I-765, I-130, etc.), USCIS assigns a unique receipt number to that specific case. You can have dozens of receipt numbers over your immigration journey, but you'll only ever have one A-number.

Who can see your A-number?

Your A-number is protected under federal law, and USCIS won't share it with unauthorized third parties.

Your employer sees your A-number during I-9 employment verification when they examine your green card or EAD. This is normal and legally required. Government agencies with lawful authority (USCIS, CBP, ICE, the State Department) can access your A-number as part of their official functions.

No private individual, company, or organization can look up your A-number without your authorization. If you receive an unsolicited phone call, email, or message asking for your A-number, treat it as a potential scam. USCIS does not contact people to ask for their A-number by phone or email.

When you need your A-number

Almost every USCIS form has a field for your A-number, including the I-485 (adjustment of status), I-765 (EAD application), I-130 (family petition), I-131 (travel document), and N-400 (naturalization). On multi-page forms like the I-485, the A-number field appears at the top of every page, so you'll need it handy throughout the entire form. Having it ready before you start any application saves time and prevents delays.

Employment verification is another common trigger. When your employer completes the I-9 form to verify your work authorization, they'll record your A-number from your green card or EAD. You don't need to provide it separately if your employer can see it on the document, but it's good to know where it is.

Beyond forms, you'll need your A-number when communicating with USCIS by phone or through your myUSCIS account, checking your case status online, responding to a Request for Evidence (RFE), and in some cases, during background checks for certain job applications.

What if you don't have an A-number?

If you've never filed an application with USCIS and haven't gone through any immigration proceedings, you likely don't have an A-number yet.

When a form asks for your A-number and you don't have one, write "N/A" or leave the field blank. Most USCIS forms include instructions telling you to do exactly this. The form will specify whether the A-number field is required or optional. For first-time applicants, it's almost always optional.

You'll be assigned an A-number automatically when USCIS processes your first application. There's no separate form to request one and no fee to get one. It happens as part of normal processing.

What if you lost or forgot your A-number?

If you can't find your A-number, you can recover it through your myUSCIS account, previous USCIS documents like the I-797 or EAD, or the USCIS Contact Center at 1-800-375-5283.

Start by checking your previous immigration documents. Go through any old green cards, EAD cards, I-797 approval notices, or letters from USCIS. Your A-number appears on all of these, and since it never changes, even a document from years ago will have the right number.

If you can't find physical documents, log into your myUSCIS account. Your A-number is linked to your account and should appear in your profile or case history. If you haven't created a myUSCIS account yet, setting one up takes a few minutes and gives you access to your case information.

You can also call the USCIS Contact Center at 1-800-375-5283. A representative can help you locate your A-number if you can verify your identity with other personal information. Wait times can be long, so try the online and document-check routes first.

If none of those options work, you can file a Freedom of Information Act (FOIA) request with USCIS using Form G-639 to access your immigration file. Expect to wait at least eight weeks for a response, and potentially longer depending on the backlog. The request will return your complete immigration record, including your A-number.

Finally, if you've worked with an immigration attorney at any point, they likely have your A-number on file from previous filings. A quick call or email to their office is often the fastest route if you have that option.

Your A-number is a permanent part of your immigration record, and one of these retrieval methods will work for your situation.

Frequently asked questions