An Alien Registration Number, usually called an A-Number, is the unique identifier that the Department of Homeland Security assigns to your immigration file. It begins with the letter “A” followed by seven, eight, or nine digits, and it stays with you for life.1U.S. Citizenship and Immigration Services. A-Number Alien Registration Number Alien Number Every form you file, every hearing you attend, and every status change links back to this single number.
What the Number Looks Like
Current A-Numbers are nine digits long. Older ones issued years ago may have only seven or eight digits.1U.S. Citizenship and Immigration Services. A-Number Alien Registration Number Alien Number If yours is shorter, add a zero after the “A” and before the first digit to bring it up to nine. Government databases and phone systems expect the full nine-digit format, and the zero padding keeps everything aligned.2United States Department of Justice. Executive Office for Immigration Review Customer Service Initiatives
The number labels what the government calls your “A-File,” which holds every immigration and naturalization record tied to you. New applications get filed under the same A-Number instead of opening a fresh folder, so any DHS agency can pull your complete history at once.3U.S. Citizenship and Immigration Services. A-File 1 Million The First A-File
Where to Find Your A-Number
The number appears on several official documents. If you hold more than one, the A-Number on each should match. A mismatch usually means a data entry error you should resolve with USCIS before filing anything new.
- Permanent Resident Card (Form I-551). Printed on the front of the card under the “USCIS#” heading.4U.S. Citizenship and Immigration Services. USCIS Number
- Employment Authorization Document (Form I-766). On the front of the card, also labeled “USCIS#.”5U.S. Citizenship and Immigration Services. 13.1 List A Documents That Establish Identity and Employment Authorization
- Immigrant visa stamp in your passport. Look in the field labeled “Registration Number.” If it shows fewer than nine digits, add a leading zero after the “A.”6U.S. Citizenship and Immigration Services. Immigrant Fee Payment Tips on Finding Your A-Number and DOS Case ID
- Notice to Appear (Form I-862). If you have been placed in removal proceedings, the A-Number sits at the top of the first page in the “File No:” field.7U.S. Immigration and Customs Enforcement. Notice to Appear DHS Form I-862
- Notices of Action (Form I-797). USCIS sends these to acknowledge receipt or approval of an application, and each one lists the A-Number tied to the case.8U.S. Citizenship and Immigration Services. Form I-797 Types and Functions
Not the Same as Other Numbers on Your Paperwork
People often confuse the A-Number with other identifiers that show up on immigration documents. Entering the wrong one on a form causes real delays.
A-Number vs. USCIS Receipt Number
Your A-Number belongs to you and stays the same no matter how many applications you file. A receipt number belongs to a specific application or petition. Receipt numbers are 13 characters long, starting with three letters such as EAC, WAC, or IOE followed by 10 digits.9U.S. Citizenship and Immigration Services. Checking Your Case Status Online You use the receipt number to check case status online. You use the A-Number whenever a form asks for your permanent immigration identifier.
A-Number vs. USCIS Number
On Green Cards issued after May 10, 2010, the “USCIS#” field is your A-Number without the leading “A.” The USCIS glossary cross-references the two terms, so when a form asks for your “USCIS Number,” you can enter the nine digits of your A-Number.4U.S. Citizenship and Immigration Services. USCIS Number
A-Number vs. Social Security Number
A Social Security Number is issued by the Social Security Administration and tracks work authorization and tax reporting. An A-Number is issued by DHS and tracks your immigration record. Non-citizens authorized to work generally have both. People who are not authorized to work may hold an A-Number without ever receiving a Social Security Number.
Who Has One
DHS assigns an A-Number when it opens a file that requires long-term tracking. Common triggers include applying for permanent residency through a family or employment petition, requesting asylum or refugee protection, and being placed in removal proceedings. Short-term visitors generally do not receive one. Entries on a tourist or business visa are tracked through the I-94 arrival and departure record rather than a permanent A-File.10Federal Bureau of Investigation. Locating the Alien Number for ATF Form 4473
When You Will Need It
Employment Verification
When you start a new job, you complete Form I-9. Lawful permanent residents typically enter their A-Number in Section 1. Authorized workers may instead provide a Form I-94 admission number or a foreign passport number, so the A-Number is not the only option, but it is the most common one for green card holders.11U.S. Citizenship and Immigration Services. Instructions for Form I-9 Employment Eligibility Verification
Naturalization
Form N-400, the application for U.S. citizenship, asks for your nine-digit A-Number near the top of the first page.12U.S. Citizenship and Immigration Services. Form N-400 Application for Naturalization USCIS uses it to pull your full immigration history and confirm eligibility.
Replacing or Renewing a Green Card
If your card is expiring, lost, or damaged, you file Form I-90. The instructions ask for your A-Number so USCIS can link the new card to your existing file, and note that it appears on any prior DHS or USCIS correspondence.13U.S. Citizenship and Immigration Services. Instructions for Application to Replace Permanent Resident Card
Immigration Court
The Executive Office for Immigration Review uses the A-Number as the primary case identifier. To check a hearing date through the automated hotline, enter the nine digits of your A-Number without the letter “A.” For an eight-digit number, enter a zero first.2United States Department of Justice. Executive Office for Immigration Review Customer Service Initiatives
State Benefits and Driver’s Licenses
Agencies that issue driver’s licenses or certain public benefits verify immigration status through the SAVE (Systematic Alien Verification for Entitlements) system. SAVE requires an immigration identifier, and the A-Number is one of the primary identifiers used. You can also track a verification case online using your date of birth and A-Number.14U.S. Citizenship and Immigration Services. SAVE CaseCheck
If You Cannot Find Your Number
Start with old paperwork. Any approval notice, receipt notice, or prior immigration document you have ever received should show the number. Even expired Green Cards still display the correct A-Number.
If nothing is on hand, file a Freedom of Information Act request with USCIS to obtain copies of records from your A-File. You can submit online through the USCIS website, which is faster and lets you track status electronically, or by mailing Form G-639. Provide as much identifying information as possible, including full name, date of birth, and country of birth. Requests for specific documents from an A-File are processed faster than requests for an entire file. If you have a scheduled hearing with an immigration judge, USCIS will prioritize your request when you include a copy of your Notice to Appear or hearing notice.15U.S. Citizenship and Immigration Services. Request Records through the Freedom of Information Act or Privacy Act
Calling the USCIS Contact Center is another route. If you can verify your identity over the phone, a representative may be able to confirm your A-Number. This is often faster than a FOIA request, though it depends on hold times and on whether the representative can locate your record with what you can provide.
The Legal Duty to Carry Your Registration Document
Federal law requires every non-citizen age 18 and older to carry their registration card or certificate at all times. This is a criminal statute, not guidance. Failing to have the document on your person is a misdemeanor punishable by a fine of up to $100, up to 30 days in jail, or both.16Office of the Law Revision Counsel. United States Code Title 8 – 1304 Forms for Registration and Fingerprinting In practice, the document most people carry is the Green Card or the Employment Authorization Document.
Related violations carry heavier penalties. Willfully refusing to register or be fingerprinted is punishable by a fine of up to $1,000, up to six months in jail, or both. Failing to report a change of address within 10 days is punishable by a fine of up to $200, up to 30 days in jail, or both, and can independently trigger removal proceedings whether or not a criminal conviction results. Submitting false information on a registration application carries the same penalties as failure to register and can also lead to removal.17Office of the Law Revision Counsel. United States Code Title 8 – 1306 Penalties