Key Takeaways
- An Alien Registration Number (A-Number) is a unique identification number assigned to many noncitizens by USCIS or the Department of Homeland Security (DHS).
- You can usually find your A-Number on your Green Card, Employment Authorization Document (EAD), or immigrant visa.
- Not every visitor or visa holder receives an A-Number. For example, you are unlikely to get an A-number if you have a B-1/B-2, F-1, or H-1B visa.
- Your A-Number is generally permanent.
Your Alien Registration Number, also called an A-Number, is one of the most important identifiers in the U.S. immigration system. Whether you're applying for a Green Card, adjusting your status, or completing another immigration form, you'll be asked to provide it. Not everyone visiting the United States receives an A-Number, though.
You can find your A-number on your Green Card, Employment Authorization Document (EAD), immigrant visa, or certain USCIS notices. Once you know where to look, you can find it quickly and ensure you fill out forms correctly.
What is an Alien Registration Number?
A person's Alien Registration Number is their permanent identification number in the U.S. immigration system.
The government uses this number to connect your immigration records, petitions, applications, and travel history under a single file. Your A-Number generally remains the same for life.
Who receives an Alien Registration Number?
Many people applying for long-term immigration benefits receive an A-Number from U.S. Citizenship and Immigration Services (USCIS), but not everyone does.
USCIS commonly assigns A-Numbers to people who are:
- Applying for a Green Card
- Applying for asylum or refugee status
- Applying for certain employment authorization benefits
- In immigration court proceedings
Who doesn’t receive an Alien Registration Number?
People who are in the U.S. temporarily for travel, school, or work typically do not receive an A-Number.
For example, you probably won’t receive an A-number if you have a B-1/B-2, F-1, or H-1B visa. However, you may receive an A-number if you later apply for an immigration benefit that requires one.
What if my A-Number is less than nine digits? Some older A-Numbers contain seven or eight digits (instead of nine digits standard in 2026). If a USCIS form requires nine digits, simply add leading zeros after the letter A: A1234567 becomes A001234567.
Where can I find my Alien Registration Number?
Your A-Number appears on several official immigration documents, but the exact location depends on the document you've received from USCIS or the State Department.
| Document | Where to Find Your A-Number |
|---|---|
| Green Card (or I-551 stamp) | Front of the card under "USCIS#" or "A#" |
| Employment Authorization Document (EAD) | Front of the card under “USCIS#” or “A#” |
| Immigrant visa | Listed as the "Registration Number" |
| Form I-797 Notice of Action | Included on many approval notices |
| Immigrant data summary | Near the top of the document |
Where is my Alien Registration Number on a Green Card?
Your A-Number appears on the front of your Green Card.
Most current Green Cards list the number under "USCIS#" or "A#" near the front of the card. If you're completing an immigration form asking for your Alien Registration Number, use this number.
Where is my Alien Registration Number on an Employment Authorization Document (EAD)?
Your A-Number is printed on the front of most Employment Authorization Documents.
Depending on when your EAD was issued, it may appear as "USCIS#" or "A#". Don't confuse it with the card number, which serves a different purpose.
Where is my Alien Registration Number on an immigrant visa?
Your A-Number appears on immigrant visas as the "Registration Number."
You'll typically find it near the upper-right portion of the visa. This only applies to immigrant visas. Most nonimmigrant visas, such as tourist or student visas, do not display an A-Number.
Can I find my A-Number on USCIS notices?
Many USCIS notices include your Alien Registration Number. If you've received an approval notice or other correspondence from USCIS, check the top portion of the document.
Many versions of Form I-797 include your A-Number alongside your personal information. If you completed consular processing abroad, your Immigrant Data Summary also lists your A-Number near the top of the page.
What should I do if I can't find my Alien Registration Number?
If you can't find your A-Number after searching for it by checking immigration documents, contact USCIS after verifying your identity.
An immigration attorney can also help you identify the correct number before you submit an application or respond to a USCIS request.
In the future, keeping digital copies of your immigration documents in a secure location can make it much easier to retrieve your A-Number.
What is an Alien Registration Number used for?
Your A-Number connects every part of your immigration record, and you'll use it when you:
- File immigration applications
- Respond to USCIS requests
- Apply for an adjustment of status
- Apply for employment authorization
- Work with an immigration attorney
- Complete many government immigration forms
Because it is such a key identifier, it's critical to enter your A-Number correctly whenever a form requests it.
When will I receive my Alien Registration Number?
There isn't a single universal point when everyone receives an A-Number and the timeline varies depending on your immigration pathway.
Many applicants receive an A-Number after USCIS accepts an application to become a lawful permanent resident, during immigrant visa processing abroad, or when applying for another qualifying immigration benefit, such as asylum.
Do H-1B visa holders have an Alien Registration Number?
Most H-1B visa holders do not receive an Alien Registration Number simply because they have H-1B status.
Since the H-1B is a temporary, nonimmigrant visa, USCIS does not automatically assign an A-Number when the visa is approved.
However, if you later plan to transition from an H-1B to a Green Card, such as through an employment-based Green Card, you'll likely receive an A-Number as part of that process.
What should I do if I don't have an Alien Registration Number?
Not everyone has an Alien Registration Number, and not everyone needs one. Many temporary visitors, tourists, exchange visitors, and some students will never receive an A-Number unless they later apply for a status that requires it.
Not all visa holders have an A-Number: If you are applying for a tourist, H-1B, most student, or treaty trader (E-1 and E-2), you will probably not be assigned an Alien Registration Number. Even if you’re filing an immigration petition or form that asks for an A-number, that field generally doesn’t apply to someone who doesn’t have an A-number.
What do I do if I'm asked for an A-Number and don't have one?
If a USCIS form asks for your A-Number and you don't have one, follow the instructions on the form. Many applications allow you to leave the field blank or indicate that no A-Number has been assigned.
If you're unsure whether you should already have an A-number, an immigration attorney can help you determine whether you have one or need one.
Is an Alien Registration Number the same as a USCIS receipt number?
No, your A-Number is not the same as a USCIS receipt number. Your A-Number identifies you, while a USCIS receipt number identifies a specific application.
Each time you file an application with USCIS, you'll receive a new receipt number. These numbers usually begin with letters such as IOE, MSC, LIN, SRC, or WAC, followed by 10 digits.
Your Alien Registration Number generally remains the same throughout your immigration history, even if you file multiple applications.
Is an Alien Registration Number the same as a Social Security number?
A-Numbers and Social Security numbers (SSNs) are not the same. These numbers are issued by different government agencies and serve different purposes. An SSN is issued by the Social Security Administration and is used for taxes, employment, and Social Security retirement or disability benefits. All United States citizens, as well as permanent residents and eligible workers, have a Social Security number.
Never input your Social Security number as your A-Number on immigration forms.
Is an Alien Registration Number the same as an EAD number?
A-Numbers and EAD numbers are different. Your Employment Authorization Document contains multiple numbers, and they are not interchangeable. The card number identifies your EAD, while your Alien Registration Number identifies your immigration record.
Do not input an EAD card number as your A-Number.
Where to get help with your immigration application
Your Alien Registration Number is a crucial piece of information in your immigration file. If you have questions about your A-Number or immigration status, an experienced immigration attorney can help you identify the correct information before you submit your application.
👉 Request a consultation with Manifest Law’s experienced immigration lawyers and get the clarity you need to move forward.
FAQs about Alien Registration Numbers
How many digits is an Alien Registration Number?
Most A-Numbers contain nine digits. Some older A-Numbers contain seven or eight digits. If a USCIS form requires nine digits, simply add leading zeros after the "A." For example, A1234567 becomes A001234567.
Does an Alien Registration Number expire?
No. Your Alien Registration Number is permanent and generally stays the same throughout your immigration history, even if your status changes or documents expire.
Can I have more than one Alien Registration Number?
Generally, no. USCIS assigns one A-Number to each person. In rare cases involving administrative errors, duplicate A-Numbers may be merged into a single immigration record.
Can I check my USCIS case status using my Alien Registration Number?
Usually not. USCIS's online Case Status tool generally requires your 13-character receipt number, not your A-Number. Your receipt number appears on Form I-797 receipt notices.
Disclaimer. This article is for general informational purposes only and does not constitute legal advice. Reading it, or contacting Manifest Law through this site, does not create an attorney-client relationship. Immigration law changes frequently, and the information here is current only as of the publication date. For advice on your specific situation, consult a licensed attorney. Prior results do not guarantee a similar outcome. This communication is attorney advertising.
About the Author
Reviewed By
Senior Immigration Attorney at Manifest Law
Henry is an Estonian American attorney licensed in Arizona with broad experience in employment-based immigration. He handles EB-1A, EB-2 NIW, O-1, and E-2 cases for founders, professionals, and creatives across industries worldwide, and has helped hundreds of clients achieve successful outcomes.
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