What Is an A-Number and Where Do You Find It?

An A-Number, or Alien Registration Number, is a unique number that the Department of Homeland Security (DHS) gives to a noncitizen to identify their immigration records. It is written as the letter “A” followed by 8 or 9 digits, such as A012345678. You will find it on a green card, a work permit, immigration court notices and many USCIS letters.

You may also see it called an “Alien Number,” “A#” or “USCIS Number.” USCIS uses it to identify your immigration records, and the immigration courts use it to find your case.

What an A-Number looks like

The USCIS glossary describes the A-Number as a unique seven-, eight- or nine-digit number. A-Numbers now have 9 digits, but older ones may have 8. EOIR’s Policy Manual gives the examples A 234 567 890 (nine digits) and A 12 345 678 (eight digits).

How to write it on forms and websites

• Immigration court (EOIR): the case status website and phone line want 9 digits and no letter A. If yours has 8 digits, type a zero first. A12345678 becomes 012345678.
• USCIS: USCIS also tells people with fewer than 9 digits to add a zero right after the A, so A12345678 becomes A012345678.
• Spaces and dashes: some documents print the number in groups, like A 012 345 678. It is still the same number. Type the digits without spaces unless a form says otherwise.

If your number has fewer than 8 digits and a system will not accept it, ask the agency or your attorney how to enter it instead of guessing.

Where to find your A-Number

A few notes:

• USCIS Number = A-Number. The USCIS employer handbook explains that the USCIS Number is the same as the A-Number, just without the “A.” According to USCIS, it appears on the front of green cards issued after May 10, 2010. Details for each card version are in the handbook’s document list.
• Immigrant visa holders. USCIS says the A-Number is also at the top of the Immigrant Data Summary you get at your consular interview, and on the USCIS Immigrant Fee handout (USCIS tips).
• Court papers. The EOIR case status site points to your DHS and court letters as the place to find it.

A-Number vs. receipt number vs. USCIS online account number

These three numbers are easy to mix up, and each one opens a different door.

According to the Form I-765 instructions, you only have an Online Account Number if you filed a form online or received a receipt number that begins with IOE. If you filed online, it is in your account profile. If you mailed a form, it is at the top of the Account Access Notice USCIS sent you. USCIS states plainly that the OAN is not the same as an A-Number.

So if the immigration court website will not find your case, make sure you did not type a receipt number or account number by mistake.

Checking a court case with your A-Number

If you are in immigration court, your A-Number is the key to your case information. You enter it, along with your nationality, on EOIR’s Automated Case Information site, or key it in on the EOIR phone line at 1-800-898-7180. If you want to save the case and be told when a hearing changes, Immigratus EOIR Case Status does that with the same A-Number. It is an independent app, not affiliated with EOIR, USCIS or any government agency, and your court notices remain the official record.

What if you don’t have an A-Number?

Not everyone has one. USCIS forms ask for an A-Number “if any,” and forms such as the I-765 tell you to write “N/A” if you do not have one. Do not invent a number or use someone else’s.

If you think you have one but cannot find it:

1. Check old papers: green card, work permit, immigrant visa, Notice to Appear, hearing notices and USCIS letters.
2. Ask your attorney or accredited representative. They usually have copies of your documents.
3. Request your records. You can ask USCIS for copies of your file through a Freedom of Information Act (FOIA) request. USCIS says these requests should be made online.

Be careful with anyone who offers to “find” or “get” an A-Number for a fee. Only DHS assigns these numbers.

Keep your A-Number private

Your A-Number is sensitive. It points to your full immigration record, and scammers use it to sound official.

• Share it only when needed: with the government agency handling your case, your attorney or accredited representative, your employer for Form I-9 when required, and family members you trust to help with your case.
• Watch out for impersonators. USCIS warns that scammers pretend to be government officials to get personal information, and EOIR has warned about fake calls that use an EOIR phone number. Hang up and check your case through official channels instead.
• Don’t post it online, including photos of your green card, work permit or court notices.
• Avoid “notarios.” USCIS says only attorneys and accredited representatives can represent you on immigration matters.

In short

Your A-Number is your main immigration ID: “A” plus 8 or 9 digits, shown as the USCIS number on green cards and work permits and printed on court and DHS notices. Keep it private, and add a leading zero when a system asks for 9 digits. To follow an immigration court case with it, see Immigratus EOIR Case Status. Questions about the app? Visit our support page.

This guide is general information, not legal advice. Last reviewed September 30, 2026.

Our apps are not affiliated with, endorsed by, or connected to USCIS, EOIR, the Department of Justice, the Department of Homeland Security, or any other government agency. They do not provide legal advice.