Your Alien Registration Number on H-1B: What It Is and Where to Find It

Your A-Number isn't your receipt number, SEVIS ID, or I-94 number — here's what it is and exactly where to find it on your H-1B paperwork.

Your employer's immigration attorney sends over an intake form for your H-1B petition, and one field asks for your "Alien Registration Number (A-Number), if any." You've never seen this term on any of your F-1 paperwork, and you're not sure whether you even have one.

Here's the direct answer: your Alien Registration Number, also called your A-Number, Alien Number, or USCIS Number, is a unique nine-digit identifier USCIS assigns to track your immigration file for as long as you deal with the agency. If you've ever received an Employment Authorization Document for OPT or STEM OPT, it's already sitting on that card under the "USCIS#" field. If you've never filed anything with USCIS before, you probably don't have one yet, and writing "not yet assigned" is a completely normal answer.

What your A-Number actually identifies

USCIS and its predecessor agency have used A-Numbers for decades to organize a person's "alien file," or A-file — the running record of every immigration benefit you apply for, from your first Employment Authorization Document through a future green card. The number itself is formatted as the letter "A" followed by nine digits. Some older files show only seven or eight digits; if you're ever filling out a form that wants nine, you add leading zeros rather than guessing at a different number.

The important thing to understand is what the A-Number is not. It is not tied to a single application. It is not a receipt confirmation. It does not reset when you change jobs or file a new petition. It is a permanent, person-level identifier, and USCIS uses it to pull together every filing you've ever made under one file.

Do you already have one

Most F-1 students get their first A-Number without realizing it, at the point they file Form I-765 for standard OPT or the STEM OPT extension. USCIS assigns the number when it adjudicates that application, and it then appears on the resulting Employment Authorization Document. If that's your history, you already have an A-Number, and you'll find it printed on your EAD card right now.

If you're moving to H-1B status directly from a change-of-status filing without ever having worked on OPT, or if your only prior USCIS interaction was a reinstatement or an earlier petition your employer handled entirely, you might genuinely be A-Number-less at this point. That's not a problem. USCIS assigns the number as part of processing whichever filing first requires one, and for a lot of first-time H-1B beneficiaries, that filing is the H-1B petition itself.

Where your A-Number actually lives

If you have one already, it's hiding in plain sight on documents you probably still have.

That last row trips up a lot of candidates. Your F-1 I-20 and your visa stamp both look official and both carry long numbers, but neither one is your A-Number.

A-Number vs. receipt number vs. SEVIS ID vs. I-94 number

This is the confusion that actually causes problems on forms, so it's worth laying out side by side. All four numbers show up somewhere in an H-1B candidate's paperwork, and mixing them up on an intake form or a DS-160 visa application can slow down processing.

The receipt number is the one you'll use most often day to day, since it's what USCIS's online case-status tool looks up. If you're not sure how to read a receipt notice or track a pending case, our guide on understanding your USCIS case status and receipt notice walks through what each field means.

How your A-Number shows up on your H-1B petition and beyond

Once you have an A-Number, expect to see the request for it repeatedly, not just once. Your employer's immigration counsel typically asks for it on the intake questionnaire before drafting Form I-129, because USCIS wants a consistent identifier tying your new petition back to any prior filings in your name. If you're consular processing rather than changing status inside the US, the DS-160 visa application also has a field for it, and leaving it blank when you do have a number can raise unnecessary questions during your interview.

The A-Number matters even more later in your career. Every future H-1B extension, every transfer to a new employer, and eventually your I-485 adjustment of status application all reference the same number. USCIS fees change from year to year across these filings — our USCIS fee schedule breakdown covers current costs across the H-1B and green card process — but the A-Number itself is one constant thread running through all of them. If you end up switching employers down the line, our H-1B transfer playbook covers what carries over and what doesn't; the A-Number is one of the things that always does.

It's also worth knowing what your A-Number is not used for. Your school's Designated School Official has no visibility into it and doesn't need it — DSOs work entirely within SEVIS, tracking your SEVIS ID, which is a completely separate number issued by a completely separate agency. If a form is asking about your F-1 record specifically, that's a DSO question. If it's asking about your USCIS immigration history, that's an A-Number question, and it belongs with your employer's immigration attorney, not your school.

If USCIS hasn't assigned you one yet

For candidates filing their first-ever petition with USCIS, here's roughly how the number gets assigned:

1. Your employer's attorney submits Form I-129 for your H-1B, noting that you don't currently have an A-Number.
2. USCIS receives the petition and generates a receipt number for that specific filing — this is the number you'll use to check case status while the petition is pending.
3. As USCIS adjudicates the petition, it opens (or locates, if one already exists) your alien file and assigns the corresponding A-Number.
4. The A-Number typically appears on your approval notice once the petition is approved.
5. From that point forward, you use the same A-Number on every subsequent USCIS filing — extensions, transfers, amendments, and eventually adjustment of status.

You don't request an A-Number separately or apply for one on its own. It's a byproduct of your first substantive USCIS filing, not a standalone process. If you're unsure whether a prior filing already generated one for you, ask your employer's immigration attorney to check rather than assuming either way — a duplicate or mismatched A-Number on a new petition can trigger processing delays that are entirely avoidable.

Common mistakes

• Writing your SEVIS ID instead of your A-Number. They're both long numbers on official-looking documents, but a SEVIS ID starts with "N" and belongs to a different system entirely.
• Confusing your latest receipt number with your A-Number. The receipt number changes with every new filing; only the A-Number stays constant.
• Assuming you don't have one when you actually do. If you've ever held an OPT or STEM OPT EAD, check that card before telling anyone you're starting from zero.
• Dropping or padding digits incorrectly. Current A-Numbers are nine digits. If your only record shows seven or eight, add leading zeros rather than guessing — and confirm the exact number with your attorney if you're not certain.
• Not writing the number down once you learn it. You'll need it again for every future filing, so save it somewhere alongside your other immigration documents rather than digging through old EAD cards each time.

Frequently asked questions

What is an Alien Registration Number (A-Number) on an H-1B petition? Your A-Number, also called an Alien Number or USCIS Number, is a nine-digit identifier that USCIS assigns to track your case file for as long as you interact with the US immigration system. It's different from your H-1B receipt number, which changes with every new filing, and from your SEVIS ID, which belongs to your F-1 school record. Once assigned, the same A-Number follows you through every future USCIS filing, including extensions and your eventual green card application.

How do I find my A-Number for my H-1B petition? Check the front of your OPT or STEM OPT Employment Authorization Document first, since the USCIS# field there is your A-Number. If you've had a prior USCIS approval notice, look for an A# field near the top of the notice. If neither applies and you've never filed anything with USCIS, you likely don't have one yet, and that's a normal answer to give your employer's immigration attorney.

Is my A-Number the same as my USCIS receipt number? No. Your A-Number is assigned once and stays with you for every future filing, while your receipt number is a 13-character code assigned fresh to each individual application or petition you or your employer files. You'll see both on many USCIS notices, but only the A-Number carries forward from one filing to the next.

What if I don't have an A-Number yet when my employer files my H-1B petition? That's common, especially if you're moving straight from F-1 status without having filed for OPT through Form I-765. Tell your employer's immigration team you don't have one rather than leaving the field blank without explanation. USCIS assigns you an A-Number as part of adjudicating the H-1B petition if you don't already have one, and that number becomes yours permanently going forward.

Does my A-Number change when I transfer employers or extend my H-1B? No. Your A-Number stays the same across H-1B transfers, extensions, amendments, and even a later green card filing, since it identifies you rather than any single petition. What does change with each new filing is your USCIS receipt number, which restarts fresh every time your employer files a new Form I-129 on your behalf.

Sorting through H-1B paperwork and want a second set of eyes on your documentation? F1Jobs — we help candidates keep their immigration filings organized through every stage of the process.