USCIS Number vs. A-Number: What They Are and Where to Find Them

The Short Answer

The USCIS number and the A-number are the same thing: a unique nine-digit Alien Registration Number assigned to every foreign national in an active USCIS record. Your USCIS online account number, by contrast, is a different number — it identifies your my.uscis.gov online account, not your immigration file. These three terms are often confused, and the confusion gets in the way of completing USCIS forms correctly.

This article explains the differences, where each one appears, and how to find them when a form asks for one of them.

The A-Number (Alien Registration Number)

The A-number, or alien registration number, is a nine-digit number that USCIS assigns to identify a specific person in USCIS records. It begins with the letter "A" followed by nine digits, though on modern documents the A is often omitted and the number appears as just nine digits. Some older records use eight-digit A-numbers, which are padded with a leading zero when entered on modern forms.

An A-number follows a person through every USCIS interaction. Once assigned, it typically does not change. A person may not receive an A-number at the very first step of their immigration journey — some nonimmigrant visa holders have no A-number — but they will be assigned one once they file a USCIS benefit that requires the number or receive a permanent resident card.

The USCIS Number Is the A-Number

When USCIS redesigned the green card in 2010 and subsequent years, they relabeled the field on the physical card from "Alien Number" (the older term) to "USCIS#" for plain-English readability. The number in the USCIS# field on a modern green card is the exact same number as the A-number in older documents. The "A" prefix is usually not printed on the card.

On the front of a green card, the USCIS# field is near the top, typically just below the photograph. It is a nine-digit number, sometimes displayed with dashes or spaces for readability.

The USCIS Online Account Number

This is where confusion sets in. The USCIS online account number is a separate identifier assigned when you create an account on my.uscis.gov. It is typically 10 to 12 digits long and is completely different from your A-number. The online account number links paper filings to your online account so you can track cases digitally — it has nothing to do with your immigration file itself.

When a form asks for your USCIS online account number, it wants the digital account identifier, not your A-number. When a form asks for your USCIS# or A-number, it wants the A-number. Reading the form field carefully is essential to avoid filing mistakes.

Where to Find Your A-Number

The A-number appears on many USCIS documents. The most common places:

• Permanent resident card (green card) — labeled "USCIS#" on the front.
• Employment Authorization Document (EAD) — labeled "USCIS#" on the front.
• Form I-797 approval and receipt notices — printed near the top as "A#" or "A-number."
• Immigrant visa stamp — printed on the visa foil.
• Form I-94 (Arrival/Departure Record) for some categories — especially those who entered on immigrant visas.
• Notice to Appear (NTA) in removal proceedings — the A-number is prominently displayed.
• Form I-90 approval notices, I-130 approval notices, I-485 receipts, and virtually every other USCIS notice for cases in progress.

Where to Find Your USCIS Online Account Number

The online account number appears:

• In your my.uscis.gov dashboard. Log in, go to your profile or account settings, and the online account number is displayed as "USCIS Online Account Number" or similar.
• On recent I-797 notices. If you filed a case online, the receipt notice sometimes includes the online account number.
• In emails from USCIS confirming account creation or linking of cases.

Not every applicant has a USCIS online account number — only people who have created an account at my.uscis.gov. If you have never used the online system, you do not have one, and leaving that field blank on a form is correct for you.

Why Forms Ask for Both

USCIS forms sometimes ask for both the A-number and the online account number because they serve different purposes. The A-number identifies you in USCIS records; the online account number links a specific case filing to a specific online account for tracking, notifications, and document uploads.

If a form asks for your A-number and you do not have one yet, leaving the field blank or writing "N/A" is the usual approach. If a form asks for your USCIS online account number and you do not have an online account, leave it blank.

Common Mistakes

• Treating the A-number as "USCIS number" in one field and "alien number" in another — they are the same. Do not enter different numbers in each field just because the labels are different.
• Entering the online account number in the A-number field. The two are very different in length and format, and USCIS will reject or RFE the filing.
• Leaving off leading zeros. A-numbers must be nine digits. Older eight-digit numbers need a leading zero to fit the modern format.
• Not knowing that you do have an A-number. Anyone who has received a green card, EAD, or even certain I-797 approval notices has an A-number, even if they have never used the term.

A Note on Privacy

Your A-number is sensitive personal information. It is not as serious a breach as a Social Security number, but it identifies you in USCIS databases and can be combined with other information to facilitate identity theft or impersonation. Do not post it on social media, do not share it with anyone you do not trust, and be cautious about services that ask for your A-number before establishing that they are legitimate.

The Bottom Line

USCIS number and A-number are the same thing — the nine-digit alien registration number that identifies you in USCIS records. The USCIS online account number is different: it identifies your my.uscis.gov account, not your immigration file. When completing a USCIS form, read the field label carefully and enter the right number in the right box. If you are unsure, check a recent I-797 notice or your physical green card — both display the A-number clearly.

When to Work with an Immigration Attorney

Not every immigration question needs a lawyer, but some do. The topics covered in this article include situations where a brief consultation with a licensed U.S. immigration attorney can save months of delay, prevent irreversible mistakes, and identify options you might not otherwise know about. Consider consulting an attorney if your case involves any of the following:

• Criminal history of any kind. Even dismissed charges, expunged records, or decades-old offenses can affect immigration outcomes. The immigration consequences of a criminal record are technical and fact-specific, and plea deals that seemed favorable in criminal court sometimes have devastating immigration consequences.
• Past immigration violations or denials. Prior visa denials, overstays, periods of unlawful presence, and prior removal proceedings all affect current options. An attorney can review your history and identify which paths remain open.
• Complicated family situations. Divorce, death of a petitioner, domestic abuse, and similar circumstances can trigger waiver eligibility or affect existing petitions in ways that require careful legal analysis.
• Business immigration matters. Employment-based cases, investor visas, and self-petitions are typically too complex for do-it-yourself filing. The evidentiary standards are demanding and the stakes are high.
• Cases that feel stuck. If your case has been sitting without action for a long time, or if you received an RFE or NOID you do not fully understand, an attorney can diagnose the problem and respond effectively.
• Anything you do not fully understand. Immigration forms are technical, and a small mistake can cascade into large consequences. When in doubt, ask someone qualified.

Finding Reliable Information

The single most reliable source of current U.S. immigration information is USCIS itself. USCIS publishes form instructions, fee schedules, processing times, policy manuals, and policy alerts at uscis.gov. When any article (including this one) references specific fees, processing times, or eligibility rules, the information can become outdated as USCIS updates its policies and fee schedules. Always verify any time-sensitive detail directly with USCIS before filing anything.

Other reliable primary sources include the U.S. Department of State (for visa bulletins and consular processing), the U.S. Department of Labor (for PERM and prevailing wage information), U.S. Customs and Border Protection (for admission and port of entry rules), and the Executive Office for Immigration Review (for immigration court procedures).

Secondary sources — including practitioner guides, law school immigration clinics, and reputable nonprofit legal aid organizations — can provide helpful explanations of how the rules apply in practice. Community forums and social media should be treated with caution: they can point you to useful resources, but they also contain a great deal of inaccurate or outdated information, and the rules change frequently enough that what was true a year ago may not be true now.

Keeping Records

One of the simplest ways to protect yourself through any immigration process is to keep careful records of everything. Copies of every filing you send to USCIS, every notice you receive, every check or money order you submit, and every piece of correspondence you send or receive become critical evidence if something goes wrong later. Keep these records organized, dated, and backed up in at least two separate places (for example, a physical folder and a digital scan).

Also keep records of everything that supports your underlying eligibility — tax returns, marriage certificate, birth certificates, medical records, employment records, property records, school transcripts, and anything else that demonstrates ties to the United States, family relationships, or program eligibility. Good records are the backbone of a strong immigration case.