Alien Registration Number (A-Number): What It Is and Where to Find It

If you have ever sat down with a USCIS form and hit the field marked "Alien Registration Number," you know the feeling. The same page also wants your USCIS Online Account Number, your I-94 record number, sometimes your SEVIS ID, sometimes a Social Security number you may not even have. None of them are the same number. None of them are interchangeable. And the form gives you almost no help telling them apart.

Your A-Number is the one identifier on that list that follows you for the rest of your life. Receipt numbers change with every filing. Cards get replaced and renumbered. Your A-Number stays put. Getting it right on the first try saves you from the kind of mismatch that turns into a Request for Evidence months later.

One more source of confusion worth clearing up early: since 2025 there has been a separate legal requirement called "alien registration," enforced through Form G-325R, that has nothing to do with locating a number on your card. Same words, different subject. We cover it below so you know which one applies to you.

What an Alien Registration Number actually is

USCIS defines it plainly: a unique seven, eight, or nine digit number that DHS assigns to a non-citizen (USCIS Glossary). It is written with an "A" in front of it, so A123456789 or A-012345678.

Think of it as the index number on a file cabinet drawer. Every application you submit, every notice you receive, every interview note an officer writes, and every entry or exit record gets filed under that number. USCIS, ICE, CBP, and the immigration courts all pull your history the same way.

Three things about the format catch people out:

Length varies by when it was issued. Older numbers are seven or eight digits. Newer ones are nine. If yours is shorter than nine digits and a form asks for nine, add leading zeros after the "A." So A1234567 becomes A001234567. You are not inventing digits, you are padding to the format the system expects.

On newer cards it is labeled "USCIS#," not "A-Number." USCIS defines the USCIS Number as a nine digit number assigned by DHS and printed on the front of Permanent Resident Cards issued after May 10, 2010 (USCIS Glossary). It is the same number. The label changed, the number did not.

Not everyone has one. If you have never filed an immigration benefit request, never been issued a green card or work permit, and never come into contact with immigration enforcement, DHS may simply not have opened a file for you. A blank field is the correct answer in that case. Do not guess.

One caveat on "unique." Duplicate files do happen, usually through name changes, transliteration differences, or clerical errors. If two of your documents show different numbers, resolve it with USCIS before filing anything else. A split file causes delays that are hard to unwind later.

Where to find your A-Number, document by document

The location depends on which document you are holding. Work down this list, newest document first.

Permanent Resident Card (Green Card, Form I-551)

Front of the card, on the line labeled USCIS#. On cards issued after May 10, 2010 it is a nine digit number (USCIS Glossary). Older cards may label the same field "A#" or "Alien #."

Do not confuse it with the long alphanumeric code on the back of the card. That is the document number, and it identifies the physical card rather than you. It changes when the card is replaced. We break the two apart in detail in our guide to the green card number and where to locate it.

Employment Authorization Document (EAD, Form I-766)

Front of the card, again under USCIS#. The EAD also carries a separate card number, so read the labels rather than picking the first long number you see. If you are renewing, the A-Number carries over unchanged, which is one of the few things about EAD card renewal that stays simple.

USCIS Notices (Form I-797)

Approval notices, receipt notices, biometrics appointment notices, and Requests for Evidence typically print your A-Number in the upper block of the page, near the receipt number. Look for a field labeled "A-Number" or "A#." This is often the fastest place to find it if your card is not in front of you.

Immigrant Visa in Your Passport

If you were issued an immigrant visa at a U.S. consulate, the visa foil lists your A-Number in the data block, usually labeled "Registration Number."

Important limit: nonimmigrant visas do not carry an A-Number. A B-1, B-2, F-1, H-1B, J-1, or L-1 visa stamp will not have one, because DHS did not open an A-file when it issued the visa. If you are on a nonimmigrant visa and a form asks for an A-Number, the honest answer is usually that you do not have one yet.

Immigration Court Documents

A Notice to Appear (Form I-862) and anything issued by an immigration judge will carry your A-Number prominently. Court records are organized around it.

Your USCIS Online Account

If you have filed online or linked a paper case, your A-Number appears in your case details at my.uscis.gov. This is worth checking before you go hunting through paper.

Quick tip: once you find it, store it somewhere you will still have access to in five years, not just in your phone. Every form you file from here on will ask for it, and the alternative is a records request that can take months.

A-Number vs the other numbers on the same form

This is where most filing errors come from. Four different identifiers, four different purposes, and form fields that sit right next to each other.

A few practical notes on each.

Receipt numbers are what you enter to check case status, and you will collect many over the years. If you are tracking a filing, this is the one you want. Our walkthroughs on checking N-400 status online and five ways to check EAD application status both start here.

The USCIS Online Account Number is not the same as your login. USCIS issues it on a Online Account Access Notice after certain paper filings, and the number appears at the top of that notice (USCIS). Many filers never receive one. The field on the form says "if any" for a reason, so leaving it blank is correct when you do not have one.

The I-94 number records a single entry or parole event, not your file. Our explainer on the I-94 arrival and departure record covers where it comes from and how to pull your history.

This is the part of the process where Immiva earns its keep. Every identifier field is validated against the format USCIS expects, so wrong-length or mismatched entries get flagged before you download your packet rather than after USCIS opens the envelope. How Immiva works has the mechanics.

What to do if you cannot find your A-Number

Work through these in order. Most people stop at step two.

1. Check your notices, not just your cards. The number is on both, and notices are usually easier to lay hands on. Any filing from the last few years almost certainly carries it.

2. Log in to your USCIS online account. If any case is linked there, the A-Number is in the case details.

3. Call the USCIS Contact Center. They cannot always release the number by phone, but it is free and sometimes works.

4. Request your immigration records. Your A-file is the government's complete record of you, and you are entitled to a copy under the Freedom of Information Act. As of January 22, 2026, USCIS requires these requests to be submitted online at first.uscis.gov after you create a USCIS account, rather than mailed (USCIS). Requests for a few specific documents are processed faster than requests for an entire A-file, so if you only need the number, ask narrowly.

If the answer turns out to be that you were never assigned one, that is a real answer. Enter nothing, or "N/A" if the form requires something. Inventing a plausible looking number to avoid a blank field creates a far bigger problem than the blank would have.

The other "alien registration": Form G-325R

This is the update most guides published before 2026 are missing, and it is the reason this page needed rewriting.

There are two different things sharing the phrase "alien registration." One is the number on your card. The other is a legal duty to register your presence with the federal government, and it is being actively enforced.

The Immigration and Nationality Act requires that, with limited exceptions, non-citizens aged 14 or older who were not registered and fingerprinted when applying for a U.S. visa, and who stay in the United States for 30 days or longer, must apply for registration and fingerprinting (USCIS). That obligation is decades old. What changed is enforcement: Executive Order 14159 in January 2025 made compliance a priority, USCIS created Form G-325R and an online process, and on June 29, 2026 DHS published a final rule adopting the earlier interim rule and updating which forms count as registration (USCIS).

Most people reading this page are already registered. USCIS lists lawful permanent residents, people admitted as nonimmigrants who were issued an I-94, anyone issued an immigrant or nonimmigrant visa before their last arrival, anyone issued an employment authorization document, people who filed Form I-485 and gave fingerprints, parolees, people placed in removal proceedings, and Border Crossing Card holders among those who have already met the requirement (USCIS). If you have an A-Number from any of those routes, G-325R is not for you.

The people who do need to register are those with none of the designated evidence of registration: for example, people who entered without inspection, and Canadian visitors who entered at a land port of entry and were not issued evidence of registration (USCIS).

Two duties attach to everyone who is registered, and these are the ones people overlook:

• Carry your evidence of registration. Anyone 18 or older who is required to register must keep it in their personal possession at all times. For a permanent resident that means the green card itself. USCIS states that failure to comply is a misdemeanor carrying a fine of up to $5,000, up to 30 days imprisonment, or both (USCIS).
• Report address changes within 10 days. USCIS states that non-compliance is a misdemeanor punishable by a fine of up to $5,000 or up to 30 days imprisonment, and that failure to comply also makes a person deportable unless the failure was reasonably excusable or not willful (USCIS).

Willful failure to register at all, or refusal to appear for biometrics when required, carries a fine of up to $5,000, up to six months imprisonment, or both (USCIS).

One thing registration is not: it is not a status. USCIS is explicit that registration documentation does not create immigration status, does not establish employment authorization, and does not confer any other benefit under the INA (USCIS). If your situation involves entry without inspection or a possible failure to register, this is territory where you want a licensed immigration attorney rather than any self-filing tool, including ours.

What happens if you enter the wrong number

Mostly, delay. USCIS runs your identifiers against its records. A number that does not match, or that matches someone else's file, can produce a Request for Evidence, a rejection at the lockbox, or a case sitting in the wrong file until someone notices.

The most common versions of this mistake:

• Entering the document number from the back of the green card instead of the USCIS# from the front.
• Entering the receipt number in the A-Number field, or the reverse.
• Dropping leading zeros on a seven or eight digit number when the form wants nine.
• Entering an old A-Number after USCIS consolidated a duplicate file.
• Filling in a made-up number rather than leaving a genuinely inapplicable field blank.

Immiva's one-time preparation fees for supported applications start at $99. Each application has its own price, and government filing fees are separate.

Wrapping up

Your Alien Registration Number is a small piece of information that a lot of paperwork depends on. Find it once, on the front of your green card or EAD or at the top of any USCIS notice, confirm it is not the document number or the receipt number, pad it to nine digits when a form asks for nine, and store it somewhere durable.

And keep the two meanings of "alien registration" apart. The number is administrative. The duty under INA 262, plus the requirements to carry your evidence of registration and report address changes within 10 days, is a legal obligation with penalties attached. Most people with an A-Number are already registered, but the carry and address rules apply to them all the same.