What Is an Alien Registration Number (A-Number), and Where Can I Find It?

In a Nutshell

An A-Number (Alien Registration Number) is a 7-9 digit number that USCIS uses to identify immigrants who apply to live in the United States permanently, as well as certain student immigrants. If you are such an immigrant and are applying for additional immigration benefits, you will probably need your A-Number to submit the required forms and to track your application. This article explains how A-Numbers work, and where you can find yours when you need it.

Written by Jonathan Petts
Updated October 2, 2022

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

An Alien Registration Number is a 7-9 digit number that U.S. Citizenship and Immigration Services (USCIS) gives to most immigrants who apply to live in the United States. It's also called an A-Number, Alien Number, or USCIS Number. USCIS uses your A-Number to track your immigration files, which are sometimes called alien files or a-files. They also require you to provide your A-Number on most immigration documents that you submit to them.

Your A-Number is very important, so you need to know how to identify it. Fortunately, the number is easy to find! Your A-Number appears on a few different documents, such as your Permanent Resident Green Card, Employment Authorization Document, and Immigrant Visa. This article will show you how to find your A-Number so that you can successfully use it to file new immigration forms or track the forms you have already filed.

How Do I Get an Alien Registration Number (A-Number)?

USCIS assigns an A-Number to all immigrants who apply to live in the United States permanently. If you apply for a Permanent Resident Card (Green Card) or another type of Immigrant Visa, you will receive an Alien Number.

If you are a noncitizen on a tourist or business visa, you will not receive an A-Number. This is because USCIS does not give A-Numbers to most immigrants who will only be in the U.S. temporarily (called "nonimmigrants"). The one exception is for immigrants who enter the U.S. on an F-1 student visa with employment authorization. These temporary immigrants will receive an A-Number.

Where Can I Find My Alien Registration Number?

Once you have applied to be a permanent U.S. resident, your A-Number will be on almost all of the documents that USCIS sends you. On most paperwork, you should be able to find your A-Number labeled "A#" near the top of the page. Here are a few examples of some of the more common documents where you can find your A-Number.

On Your Employment Authorization Document

You can find your A-Number on your Employment Authorization Document (EAD). This is also referred to as a work permit or work authorization. In the example below, the A-Number is the nine-digit number below "USCIS#":

Work Authorization Card

On Your Permanent Resident Green Card

If you have a Green Card, and the card was issued by USCIS after May 10, 2010, then your Alien Registration Number (A-Number) is the same as your nine-digit USCIS# marked in this example:

Permanent Resident Card with USCIS number

If you are Green Card-holder with a card issued by USCIS between 2004 and May 10, 2010, then your Alien Registration Number (A-Number) will appear on your card as shown below:

Permanent Resident Card pre-2010

On Your Immigrant Visa

If you do not have any other ID cards from USCIS, you may find your Alien Registration Number (A-Number) on an Immigrant Visa Stamp in your passport. Your A-Number is the nine-digit number underneath Registration Number:

Immigrant Visa with Registration Number

On Your USCIS Immigrant Fee Handout

The Immigrant Fee handout is a document from USCIS that tells you how to pay your USCIS immigrant fee. If you applied for a consular Green Card, you should have received this document when you attended your interview at the U.S. embassy or consulate. You can find your Alien Registration Number (A-Number) in the top right corner of the fee handout:

Immigrant Fee A-Number

On Your Immigrant Data Summary

If you applied for a Green Card from abroad via consular processing, you can find your A-Number on the Immigrant Data Summary. This is the first page of your immigrant visa package from USCIS. Your Alien Registration Number (A-Number) should be right at the top of the Data Summary as shown here:

Immigrant Data Summary A-Number

On Your Notice of Action

Your Notice of Action (Form I-797C) from USCIS often contains your A-Number. If your I-797C contains your A-Number, the number will be under "USCIS#" on the notice:

Notice of Action A-Number

Alien Registration Numbers FAQs

Here are the answers to some of the most commonly asked questions about A-Numbers.

Is a USCIS Case Number the Same Thing as an A-Number?

No. USCIS uses your Alien Registration Number (A-Number) to track you throughout their systems and across multiple applications. By contrast, a USCIS Case Number is only used in one specific application. Since these numbers are not the same, you need to know how to tell them apart. Your A-Number is a nine-digit number. A USCIS Case Number is 13 characters — three letters (usually "EAD" or "MSC"), followed by 10 numbers.

Is a Social Security Number the Same Thing as an A-Number?

No. The government issues a Social Security number to eligible immigrant workers in the United States who apply for one. USCIS issues an A-Number to immigrants who apply to live in the U.S. permanently. Many immigrant workers have both a Social Security number and an A-Number.

Is an EAD-Number the Same Thing as an A-Number?

Yes. There are two important numbers on an Employment Authorization Document card:

  1. The Employment Authorization number: This is the nine-digit number below where it says "USCIS#." The Employment Authorization number is the same as your Alien Registration Number (A-Number).

  2. The EAD card number: This number is below the heading "Card#," and is three letters followed by ten numbers. The EAD card number is not the same as your A-Number.

Is a USCIS Online Account Number the Same Thing as an A-Number?

No. The A-Number is a nine-digit number used by USCIS to track all immigrants applying for permanent status in the United States. The USCIS Online Account Number is only assigned if you choose to make an online account and serves as an additional way to help USCIS track your application.

What Should I Do if I Can't Find My A-Number?

If you can't find your A-Number on any of the documents listed above, don't worry! You can request your number from USCIS using a simple process. To do this, you will need to file a FOIA request (Freedom of Information Act) with USCIS. This process is free, and you can learn about it on the USCIS website.