Alien Registration Number Lookup: Where to Find It and How to Recover It

Your Alien Registration Number appears on your Green Card, work permit, immigrant visa stamp, and virtually every notice USCIS has ever sent you. It’s a seven-, eight-, or nine-digit number preceded by the letter “A,” so an alien registration number lookup usually takes a minute of digging through your immigration paperwork. If nothing you have shows the number, you can get it from the USCIS Contact Center by phone or by filing a records request online.

What the Number Looks Like

The Department of Homeland Security assigns the A-Number as a unique, permanent identifier for non-citizens in the immigration system.¹ The number stays with you through status changes, green card renewals, and even naturalization.

It can be seven, eight, or nine digits. When a form asks for nine digits and yours is shorter, pad it with zeros after the “A” until you hit nine. A12345678 becomes A012345678.²

Where to Find Your A-Number on Documents

Start with what you have. The A-Number is on almost every document USCIS has issued you, but the label changes from one document to the next, which is what trips most people up.

Permanent Resident Card (Green Card, Form I-551). Look for the field labeled “USCIS#” on the front. Some older versions also show it on the back.³
Employment Authorization Document (EAD, Form I-766). Also labeled “USCIS#.”³
Immigrant visa stamp in your passport. Labeled “Registration Number.”²
Certificate of Naturalization (Form N-550). Labeled “USCIS Registration No.”⁴
Notice of Action (Form I-797). Any approval notice, receipt notice, or request for evidence lists your A-Number near the top.
Immigrant data summary and USCIS Immigrant Fee handout. Both show the A-Number if you received them during your immigrant visa process.²

Before assuming the number is truly lost, dig through old correspondence. USCIS prints the A-Number on nearly everything it mails, so even a biometrics appointment letter or a routine scheduling notice will carry it.

How to Retrieve a Lost A-Number

If you’ve searched every document and still can’t find it, you have three ways to recover the number. Pick based on how quickly you need it and how much of your file you also want.

Call the USCIS Contact Center

The fastest option is the USCIS Contact Center at 800-375-5283 (TTY 800-767-1833), open Monday through Friday, 8 a.m. to 8 p.m. Eastern.⁵ Have any receipt notices and identifying details ready; the agent will verify your identity before releasing the number. A phone call won’t produce a replacement document, but it can get you the digits themselves in time to finish a pending form or meet a deadline.

File a FOIA Request Online

For a fuller record, file a Freedom of Information Act request to access your immigration file (the “A-File”), which contains your A-Number along with the underlying documents. As of January 22, 2026, USCIS requires all FOIA and Privacy Act requests to be submitted online at first.uscis.gov after you create a USCIS account.⁶ Paper Form G-639 still exists, but USCIS directs everyone to the online portal for faster processing.⁷

Include your full name (and any other names you’ve used), your date of birth, and any receipt or case numbers you remember. The more specific you are about what you need, the faster USCIS responds. Asking for a single document processes much more quickly than asking for the entire A-File.⁶ Most individuals requesting their own records pay nothing.⁸

One boundary worth knowing: if the records you need are held by Customs and Border Protection rather than USCIS (apprehension records, I-94 records, inspection records), you have to go to CBP directly. Those requests don’t run through the USCIS FOIA portal.⁶

Immigration Court Records

If you’re currently in removal proceedings or have a past immigration court case, the Executive Office for Immigration Review may be able to help. The EOIR hotline at 1-800-898-7180 can locate your case and confirm your A-Number once you verify your identity.⁹

Replacing the Documents Themselves

Knowing the number is one thing. Getting a replacement card or notice is another, and the forms are not interchangeable. Filing the wrong one is where people burn months and filing fees.

Replacement Green Card. File Form I-90, Application to Replace Permanent Resident Card.¹⁰
Duplicate approval notice (Form I-797). File Form I-824, Application for Action on an Approved Application or Petition. The filing fee is $590, though it’s waived for VAWA self-petitioners, T and U visa holders, Special Immigrant Juveniles, and certain other humanitarian categories. A duplicate I-797 reproduces only the approval information from the original notice; it does not include a copy of the underlying petition.¹¹¹⁰
Replacement travel document (Form I-512/I-512L). File Form I-131.

Don’t file Form I-824 to replace a Green Card, EAD, or I-94. USCIS explicitly says it will not process I-824 for those replacements.¹⁰ Each document type has its own form.

A-Number, Receipt Number, and Online Account Number

Three different numbers float around the immigration system, and mixing them up on a form causes real problems. If you enter a receipt number where the form wants an A-Number, or vice versa, the system won’t match you to the right record.

A-Number. Permanently tied to you as an individual. Same number across every application you file, every status change, and even after you naturalize. Always starts with “A.”
Receipt Number. Tied to a single application or petition, not to you. Every new form generates a fresh 13-character receipt number. The first three letters indicate the service center or filing method: LIN for the Nebraska Service Center, SRC for the Texas Service Center, IOE for applications filed online.¹²
USCIS Online Account Number. Used only for logging into and managing your account on the USCIS online filing portal. It has no connection to your immigration record and won’t appear on any official immigration document.

This distinction also decides which number to use when checking case status. The USCIS Case Status Online tool does not accept your A-Number; it requires the 13-character receipt number from your I-797 notice.¹² For immigration court cases, it’s the opposite: EOIR’s Automated Case Information System uses your A-Number as the lookup key, either online or by calling 1-800-898-7180.¹³

Keeping Your A-Number Safe

The Department of Homeland Security classifies the Alien Registration Number as sensitive personally identifiable information, in the same category as a Social Security number.¹⁴ Combined with other personal details, an A-Number in the wrong hands can be used to file fraudulent applications, intercept correspondence about your case, or commit identity theft.

Don’t post it on social media or in online forums. When you email documents that contain the number, use a password-protected file rather than pasting the number into the body of the message. An attorney or accredited representative needs it. A landlord, an employer’s HR staff outside of official I-9 employment verification, or a random “immigration consultant” generally does not.

1
U.S. Citizenship and Immigration Services. A-Number/Alien Registration Number/Alien Number
2
U.S. Citizenship and Immigration Services. Immigrant Fee Payment: Tips on Finding Your A-Number and DOS Case ID
3
U.S. Citizenship and Immigration Services. 13.1 List A Documents That Establish Identity and Employment Authorization
4
U.S. Citizenship and Immigration Services. Certificate of Naturalization Form N-550
5
U.S. Citizenship and Immigration Services. USCIS Contact Center
6
U.S. Citizenship and Immigration Services. Request Records through the Freedom of Information Act or Privacy Act
7
U.S. Citizenship and Immigration Services. Form G-639, Freedom of Information/Privacy Act Request
8
Department of Homeland Security. FOIA Fee Structure and Waivers
9
Executive Office for Immigration Review. Check Case Status
10
U.S. Citizenship and Immigration Services. Form I-824, Instructions for Application for Action on an Approved Application or Petition
11
U.S. Citizenship and Immigration Services. G-1055 Fee Schedule
12
U.S. Citizenship and Immigration Services. Checking Your Case Status Online
13
Executive Office for Immigration Review. EOIR Case Information
14
Department of Homeland Security. DHS Handbook for Safeguarding Sensitive PII