Alien Number (A-Number): What It Is, Where to Find It, and Why You Need It

Alien Number (A-Number): What Is It?

The Alien Number, also known as the A-Number or “alien registration number,” is a unique nine-digit identification number assigned to immigrants in the United States by the U.S. Citizenship and Immigration Services (USCIS). Think of it as your personal ID within the U.S. immigration system. It functions similarly to a social security number or tax ID, but within the immigration context.

The abbreviation "A-Number" comes from Alien Registration Number. It is assigned to individuals applying for a green card, asylum, naturalization, work visa, or any form of legal status in the U.S. The number starts with the letter “A” followed by 7 to 9 digits (e.g., A123456789).

This number is used to track your case history, submit forms, change status, and more. Even if you move states or change your name, your A-Number stays the same for life. It remains in the USCIS archive and can be used for any legal action connected with your immigration status.

Why Is the A-Number Important?

The A-Number serves many critical functions. First and foremost, it connects all your immigration documentation into one profile. Imagine having a massive file with your petitions, forms, visas, work permits, green cards, court decisions, etc. — all these documents are linked via your A-Number.

Key reasons why the A-Number is essential:

• Tracking your USCIS case. You can use your A-Number to log in to USCIS systems and check your case status.

• Identity verification. The number is used to confirm your immigration identity in official situations.

• Immigration and legal processes. If your case goes to court or you file an appeal, your A-Number is tied to it.

• Employment and taxes. Some employers request your A-Number when processing your Employment Authorization Document (EAD).

• Applying for citizenship. When submitting Form N-400 (Naturalization), the A-Number must be included.

In short, your A-Number is a central element in your U.S. immigration journey.

Where to Find Your A-Number

Finding your A-Number is relatively easy if you’ve interacted with USCIS before. Look for it in:

• Green Card (Permanent Resident Card). The back of your green card shows “USCIS#” — that’s your A-Number.

• Employment Authorization Document (EAD). It appears next to “USCIS#” as well.

• USCIS Notices. For example, Form I-797 (Notice of Action) typically lists your A-Number at the top.

• Immigration forms. It’s found in Forms I-485, I-130, I-140, I-589, etc.

• Court documents. If you’ve gone through immigration court, your number will be listed in court orders or hearing notices.

If you have multiple immigration-related documents, your A-Number is most likely included in all of them.

What Does the A-Number Look Like?

The A-Number usually has 9 digits and looks like: A123456789. Sometimes, it may have 7 or 8 digits, like A01234567. However, when filling out forms electronically, always use 9 digits, adding zeros at the beginning if needed (e.g., A000123456).

You might see it labeled as:

• USCIS#

• A#

• Alien Registration Number

Make sure not to confuse it with your USCIS Receipt Number (e.g., WAC1234567890), which is different and tied only to a specific application, not to your identity.

The A-Number and Immigration Documents

Almost every important immigration document includes your A-Number, which makes it vital:

• USCIS Forms — nearly all require you to include your A-Number if you have one.

• Court documents — motions, decisions, and hearing notices feature your A-Number.

• Decision letters — both approvals and denials list your number.

• Cards and ID documents — EADs, green cards, and other USCIS IDs include it.

Without an accurate A-Number, your case could be lost or mismatched in the system.

A-Number vs. USCIS Case Number — What’s the Difference?

Many people confuse these two terms. The A-Number is your permanent personal identifier in the system. The USCIS Case Number (also known as Receipt Number) is a unique identifier for a specific application. For example, you apply for a green card — you get a Receipt Number. Later, you apply for a work permit — that’s a new Receipt Number. But your A-Number stays the same.

Attribute	A-Number	USCIS Case Number
Unique to	One person	One application
Format	A123456	One application
Format	A123456789	WAC1234567890
Purpose	Personal identification	Case tracking

Can You Fake an A-Number?

Faking or forging an A-Number is a serious crime in the U.S. This number is considered a federal identifier, and attempting to use a fake one can lead to criminal charges, deportation, and a permanent ban from the country.

Unfortunately, scams do happen. Some shady agents may offer “fake” A-Numbers, promising faster processing. To protect yourself:

• Never trust unauthorized immigration consultants.

• Verify your A-Number using official USCIS sources.

• Do not share your A-Number unless necessary — it can be used for fraud.

Treat your A-Number as a confidential personal identifier, like a passport number or Social Security Number.

What If You Lost Your A-Number?

Losing your A-Number is stressful, but it can be resolved. Since it's stored in USCIS records, there are several ways to retrieve it:

1. Check old documents. Look through past forms, EADs, green cards, or USCIS letters.

2. Log into myUSCIS account. Your number may be visible in your profile.

3. Submit a FOIA request. Under the Freedom of Information Act, you can request your immigration file from USCIS.

4. Call USCIS. Officers may confirm your A-Number after verifying your identity.

5. Hire an immigration attorney. They can assist in recovering your number quickly.

Your number still exists in the system — it’s just a matter of accessing it.

How to Get an A-Number for the First Time

If you haven’t yet interacted with USCIS, you don’t have an A-Number. You’ll receive one after your first official immigration process, such as:

• Applying for a green card (Form I-485)

• Filing for asylum (Form I-589)

• Requesting work authorization (Form I-765)

• Submitting a petition for a relative (Form I-130)

Once your case is processed, you’ll receive a Form I-797 notice, which usually contains your A-Number. It’ll also appear on future documents from USCIS.

Tip: Make copies of all official correspondence and keep them secure. You’ll need your A-Number many times.

Who Gets an A-Number?

Not everyone entering the U.S. gets an A-Number — it’s mainly for individuals going through the legal immigration process. Specifically:

People who receive an A-Number:

• Green card applicants (through work, family, asylum, etc.)

• Asylum seekers

• Refugees and TPS recipients

• Naturalization applicants

• Immigration court participants

• EAD holders

People who DON’T receive an A-Number:

• Tourists, students, or short-term visa holders (e.g., B1/B2)

• Visa Waiver Program travelers

• People who’ve never filed with USCIS

If you're unsure whether you have an A-Number, check your visa, I-94 form, or any USCIS-issued documents.

Can You Have More Than One A-Number?

USCIS rules state that a person should only have one A-Number. However, duplicate numbers can happen due to:

• Multiple applications filed through different attorneys

• Typos or different names used in forms

• Name changes or marital status updates

If you’ve been assigned two A-Numbers, request a file merge immediately. This can be done via Form G-639 or with the help of an immigration attorney.

Having multiple active A-Numbers can cause delays and confusion in your case processing.

How to Use the A-Number to Check Case Status

Your A-Number helps you track your immigration case, especially if you're involved in court proceedings or EOIR matters.

Here’s how to use it:

1. USCIS Website. Log in to your myUSCIS account and enter your A-Number to access case info.

2. EOIR Case Status. On the EOIR website (immigration court), input your A-Number to view hearing dates and decisions.

3. By phone. Call USCIS at 1-800-375-5283 and follow the prompts to check your status using your number.

Remember: The A-Number gives general information; you’ll still need a Receipt Number for specific case updates.

A-Number and the Green Card

On your green card (Permanent Resident Card), the A-Number is shown as USCIS#. It confirms your lawful permanent resident status and is used for:

• Employment verification

• Filing taxes

• Traveling

• Applying for citizenship

Even if your green card expires, the A-Number remains active and valid for life.

A-Number and Naturalization

When submitting Form N-400 (Application for Naturalization), your A-Number is required. It allows USCIS to find your full immigration history.

Tips:

• Double-check the number is correct

• Ensure consistency across all documents

• Match it with your green card number

After naturalization, the A-Number remains in USCIS records but is no longer actively used, since you become a U.S. citizen.

Frequently Asked Questions (FAQ)

1. Can children have an A-Number?

Yes, if a child is part of an immigration case, they are assigned an A-Number too.

2. How long is the A-Number valid?

It is valid for life.

3. Can the A-Number be changed?

No. It is permanent and cannot be modified.

4. What if there’s a mistake in the A-Number on my documents?

File Form G-325A or contact USCIS to request corrections.

5. Can I use someone else’s A-Number?

Absolutely not. It’s immigration fraud and can result in deportation.

The Alien Number is more than just a sequence of digits — it's the key to your U.S. immigration identity. It follows you from the very first application to your final immigration status. Knowing its purpose and using it correctly ensures a smoother journey through the complex U.S. immigration system.

Store your A-Number safely, use it responsibly, and double-check all forms to avoid issues