How To Get Alien Registration Number: A Complete Guide To Finding Your USCIS A-Number

An Alien Registration Number, or A-Number, is a unique nine-digit identification number assigned by the Department of Homeland Security to every non-citizen who interacts with immigration services. You can find your A-Number on official USCIS correspondence, immigration visas, green cards, and employment authorization documents, or recover a lost number by filing a Freedom of Information Act (FOIA) request.

Pre-Procedure Planning & Document Audit

Locating or obtaining an Alien Registration Number requires a methodical audit of your immigration history, physical documents, and digital records. The A-Number serves as the primary tracking identifier within the Department of Homeland Security database, appearing on virtually all paperwork generated by U.S. Citizenship and Immigration Services (USCIS), U.S. Customs and Border Protection (CBP), and the Executive Office for Immigration Review (EOIR).

• Essential Documents & Materials: Physical Permanent Resident Card (Green Card), Employment Authorization Document (EAD), U.S. Visa foil, Form I-797 (Notice of Action), Form I-20 (for students), and prior deportation or removal orders if applicable.
• Mandatory Prerequisite Knowledge: Understanding the numeric structure. An A-Number always begins with the letter "A" followed by eight or nine digits (for example, A123456789). If an older record shows only eight digits following the "A", a zero is typically inserted immediately after the "A" to meet modern digital database parameters.
• Estimated Time & Cost Benchmarks: Locating the number through existing documents takes under ten minutes. Recovering a lost number via a USCIS Account takes 24 to 48 hours, whereas retrieving historical records through a formal Freedom of Information Act (FOIA) request can take anywhere from four weeks to several months, with standard processing generally free of charge for basic file retrievals.

Step-by-Step Alien Registration Number Retrieval Workflow

Step 1: Inspect Your Existing Immigration Documents

• Review every physical and digital document you have ever received from U.S. immigration authorities. Look specifically at the top right-hand corner of Form I-797 (Notice of Action) approval or receipt notices, where the A-Number is explicitly labeled.
• Examine your machine-readable immigrant visa foil located inside your passport; the registration number is frequently designated as the "Registration Number" or listed directly beneath the passport number.
• Check older pay stubs, tax returns, or employment onboarding paperwork if you previously held work authorization, as employers are legally mandated to record this identifier on Form I-9.

Pro-Tip: Do not confuse your USCIS Online Account Number with your Alien Registration Number. The Online Account Number is usually a 12-digit number used solely for navigating the digital portal, whereas the A-Number is the permanent nine-digit identifier.

Step 2: Log Into Your Online USCIS Account

• Navigate to the official USCIS online portal and sign in using your multi-factor authentication credentials if you have previously filed petitions electronically.
• Access your dashboard profile or review historical case filings listed under your account history.
• Click on any active or historical receipt notice PDF generated within the portal to view the document details, where your A-Number will be displayed prominently alongside your case status.

Warning: Avoid unverified third-party websites offering expedited A-Number retrieval services, as these platforms may compromise sensitive personally identifiable information (PII).

Step 3: Review Past Employment Verification Records

• Contact the human resources department of your current or past U.S. employers to request a copy of your historical Form I-9 (Employment Eligibility Verification).
• Employers are required to retain Form I-9 for three years after the date of hire or one year after employment termination, whichever is later.
• Inspect Section 1 or Section 2 of the archived Form I-9, where you or your employer recorded your Alien Registration Number or Alien Authorization Number at the time of hire.

Step 4: Submit a Freedom of Information Act (FOIA) Request

• If all personal records and employer files are exhausted, visit the official USCIS FOIA portal (known as FIRST) to submit an electronic request for your Alien File (A-File).
• Create an account, complete Form G-639 (Freedom of Information Act/Privacy Act Request), and upload a copy of a government-issued photo identification to verify your identity.
• Specify in your request that you are seeking your complete immigration file to retrieve your lost Alien Registration Number, and monitor the portal for digital delivery of your records.

Comparison of A-Number Locations by Document Type

Common Search Failures and Field Fixes

• Failure: Confusing the USCIS Account Number with the Alien Registration Number.
  
  
  • Root Cause: Digital portals generate a separate 12-digit account identifier that resembles an identification number but is not accepted by immigration courts or external agencies as an A-Number.
  • Actionable Fix: Cross-reference the number against physical paper notices issued by USCIS, ensuring it adheres strictly to the letter "A" followed by nine digits.
• Failure: Inability to locate records due to a legal name change.
  
  
  • Root Cause: Filing a FOIA request under a newly acquired married or hyphenated name when the historical immigration file was created under a maiden name.
  • Actionable Fix: Provide all historical aliases, maiden names, and previous legal names within the "Other Names Used" fields of the Form G-639 FOIA application.
• Failure: Missing digits or formatting errors during data entry.
  
  
  • Root Cause: Omitting the leading letter "A" or failing to account for historical eight-digit formats.
  • Actionable Fix: Prepend the letter "A" to the numeric string, and if the historical record contains only eight digits, insert a zero immediately after the "A" (e.g., A012345678).

Frequently Asked Questions

What does an Alien Registration Number look like?

An Alien Registration Number always starts with the letter "A" followed by eight or nine numerical digits. For example, a standard modern format appears as A123-456-789 or A123456789. It is entirely unique to the individual and remains unchanged throughout their interactions with the U.S. immigration system.

Do all non-citizens possess an A-Number?

No, temporary visitors such as tourists entering on B-2 visas, business travelers on B-1 visas, or participants in the Visa Waiver Program do not automatically receive an Alien Registration Number. An A-Number is generally assigned only when an individual applies for permanent residency, files specific immigration petitions, or becomes subject to removal proceedings.

Can I work in the U.S. without knowing my A-Number?

Employers are legally required to verify your employment eligibility using Form I-9, which demands documentation that typically displays your A-Number if you are a lawful permanent resident or authorized alien. Working without providing this valid identification or equivalent work authorization violates federal employment verification statutes.

How long does it take to retrieve a lost A-Number via FOIA?

Processing times for a Freedom of Information Act request through the USCIS electronic portal generally range from four weeks to several months depending on agency backlogs and the complexity of your historical file. Simple requests for basic file verification are frequently processed faster if the applicant provides clear identifying biographical data.

Is my A-Number the same as my Social Security Number?

No, the Alien Registration Number is issued exclusively by the Department of Homeland Security for immigration tracking, whereas a Social Security Number is issued by the Social Security Administration for tax and employment administration. While both numbers are required for authorized workers, they serve entirely separate legal and administrative functions.

Secure Your Immigration Records Today

Take control of your immigration status by auditing your personal files today to ensure your Alien Registration Number is correctly documented for future employment, travel, or naturalization petitions. Begin your document review or submit a secure electronic records request through official government channels to maintain uninterrupted compliance.