When an alien applies to live in the United States, you will receive an alien registration number to show your legal identity. This is an important number to keep in mind. If you don’t remember what your Alien Registration Number is, in this article, we will show you a detailed guide on where to find your Alien Registration Number and what you can do with this number.

Alien Registration Number

What Is Alien Registration Number?

An Alien Registration Number, also known as an A-Number, Alien Number, or USCIS Number, is a 9-digit number that immigrants can obtain from U.S. Citizenship and Immigration Services (USCIS) if they want to live in the United States. You can find your A- Number on a few different documents, such as your Permanent Resident Green Card, Employment Authorization Document, and Immigrant Visa. In addition, you can use it to submit new immigration forms or track the forms filed.

Where to Find Alien Registration Number

After you become a permanent U.S. resident, you can find the A-number on almost all USCIS documents with the label “A#” near the top of the page. Here we will show you some common documents where you can find your A-Number.

On EAD Card

EAD Card

You can find your A-number on your Employment Authorization Document (EAD), which is a work permit or work authorization. On the card, you can see the nine-digit number below “USCIS#, which is the A-Number.

On Green Card

green card

If your Green Card was issued by USCIS after May 10, 2010, your A-Number will be marked as nine-digit USCIS#. If you have a Green Card issued by USCIS between 2004 and May 10, 2010, your Alien Registration Number will appear on your card with the “A#” under the title.

On Immigrant Visa

immigrant visa

You can also find your Alien Registration Number on an Immigrant Visa Stamp in your passport. The A-Number will be displayed as the nine-digit number below the Registration Number.

USCIS Immigrant Fee Handout

USCIS Immigrant Fee Handout

You can find the number on the USCIS Immigrant Fee handout, a document telling you how to pay your USCIS immigrant fee. You will receive it when you need to attend 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.

On Immigrant Data Summary

Immigrant Data Summary

You can find the A-number at the top of the Immigration Data Summary. This is an immigration file from USCIS when you apply for a Green Card from abroad. It shows all your basic information on the paper. 

On Notice of Action

You can find the A-number on the USCIS Notice of Action (Form I-797C). You can check the number under “USCIS#” on the notice.

Alien Number Types

Most A-numbers are nine digits, but there are some A-numbers that are less than nine digits. If your A-number is not up to nine digits, you are required to place a zero (0) between the “A” and the digit to make your A-Number a complete nine digits.

Here you can obtain the Alien registration number by checking the immigration documents as mentioned above. 

What Can I Do with My Alien Registration Number?

If you don’t know what you can do with your Alien Registration Number, the function of your A-Number is similar to a U.S. citizen and permanent resident’s Social Security Number. It is assigned specifically to an alien as a form of identification. In addition, your alien registration number can be used by the government in many aspects. 

  • It can identify the number of resident immigrants in the United States.
  • It can track your immigration records and other legal or illegal activities.
  • It can track you in case of an emergency.

Mostly, you can use the Alien registration number to prove your identity when you want to apply for a job, driver’s license, and social security number as an immigrant in the United States. 

What to Do if I Lose My Alien Number?

If you lose any alien number, you will be able to access your A- Number through the online Freedom of Information Act (FOIA) system or you can make an appointment with USCIS. They will help you access the A-number. Normally, you can check the Alien number through the immigration forms.


👉 Is the alien number the same as the i-94?

No, your Alien Registration Number is not the same as your I-94 number. The alien registration number I 94 on the passport is an 11-digit number that should be found on Form I-94. When entering the United States for the first time, you must complete the form. However, the A-number is a form of identification for foreign immigrants.  

👉 Is the USCIS number the same as the green card number?

No. As the green card number usually begins with three letters followed by a series of 10 numbers, the USCIS number is the 9-digit number shown on immigrant documents. Therefore, your green card number is different from your alien registration number.

👉 Is the Alien Registration Number mandatory?

Yes. If you are an immigrant to the United States, you must have an Alien Registration Number. As a result, you can access social benefits and prove your U.S. identity. In addition, U.S. Citizenship and Immigration Services (USCIS) will track your immigration case with this Alien Registration Number. After becoming a U.S. citizen, you are not required to have an Alien Registration Number.

👉 Will I receive a new alien registration number if I update my immigration status?

No.  When you obtain the alien registration number, it will not expire or be renewed. It will be the only number that will not be changed. As a result, you will not receive a new alien registration number if you update your immigration status.


All in all, you can complete the alien registration number lookup in many ways mentioned above, if you don’t remember the alien registration number. Since it is important for you to keep the alien registration number, it is necessary for every foreign immigrant to know where to find the A-number.

By Erin Lo

My passion lies in the intersection of technology and storytelling, and I'm thrilled to explore the world of AI and its impact on passport photography. I strive to make complex concepts easy to grasp for readers, sharing the wonders of AI in our everyday lives. Beyond writing, I find inspiration in art, diverse cuisines, and outdoor adventures. Contributing to AiPassportPhotos' innovative approach is an exciting journey, making passport photos and more creative pictures simpler and more efficient through the power of AI.