An Alien Registration Number (commonly called an A-number) on an Employment Authorization Document (EAD) is a unique identifier issued by U.S. Citizenship and Immigration Services (USCIS) to noncitizens establishing their identity and immigration status. The number appears on the front of the EAD card and is used by employers, agencies, and USCIS to track employment authorization, link records, and verify work eligibility. It is distinct from a Social Security Number and remains valid for the duration of the underlying immigration status, even if the document expires and is renewed.
What the Alien Registration Number Is and Why It Matters
The Alien Registration Number, or A-number, is a lifelong identifier assigned to most people who interact with U.S. immigration authorities. On an EAD, the A-number allows USCIS and employers to match the card to the underlying immigration record and employment authorization case. This matters because it helps prevent processing errors, ensures that only authorized workers are employed, and provides a consistent reference when status changes, renewals, or adjudications occur. The A-number is not an employment authorization number itself, but it ties directly to the authorization recorded on the EAD.
Where to Find the A-Number on an EAD
On a physical EAD card, the A-number is printed in a dedicated field on the front of the card. It typically appears near the top or bottom, often labeled as "A-number" or formatted as "No." followed by the digits. On the USCIS online account profile, when viewing or downloading the EAD record, the A-number is displayed alongside other case details. In email or case correspondence from USCIS, the A-number is usually included in the subject line or header so recipients can reference the correct file.
Typical A-Number Placement on EAD Documents
- Front of the card: labeled as A-number or No.
- USCIS online account: shown in the case details section.
- Correspondence and receipts: included for reference and tracking.
How A-Numbers Are Formatted
While formats can vary by issuance year and service center, A-numbers historically followed a consistent numeric structure. Older numbers often had nine digits, sometimes preceded by a letter. More recent numbers frequently appear as nine-digit figures without prefix letters, though exceptions exist depending on when and where the number was issued. Because there is no single public schema released by USCIS, variations can be seen across different generations of cards and records.
Common A-Number Formats (Illustrative Examples)
| Attribute | Verified Detail | Source Type |
|---|---|---|
| Length | Typically 9 digits; may include a leading letter in older numbers | USCIS documentation and samples |
| Label on EAD | A-number or No. | Physical EAD card samples |
| Uniqueness | Assigned to each noncitizen for life | USCIS policy and records |
The A-Number Versus Other Identifiers
It is important to distinguish the Alien Registration Number from other identification numbers that appear on immigration and employment documents. Unlike a Social Security Number, which is issued by the Social Security Administration for tax and benefit purposes, the A-number is issued by USCIS for immigration purposes and reflects status and authorization. The EAD itself is the document that grants work authorization; the A-number is the persistent identifier linked to the person and case. Service Provider Numbers or case numbers may appear on notices, but they are not substitutes for the A-number when verifying identity or employment records.
Quick Comparison of Key Numbers on EAD Materials
- A-number: Lifelong USCIS identifier linked to the person; found on EAD and immigration records.
- EAD Number: Document-specific number on the physical card that authorizes employment; separate from the A-number but associated with it.
- Social Security Number: Used for tax reporting and employment eligibility verification; issued by SSA, not USCIS.
- Case Number (Receipt Number):Used to track a specific application or case through USCIS; different from the A-number.
Using the A-Number in Employment and Verification
Employers and authorized representatives use the A-number to cross-reference immigration records with employment eligibility. On Form I-9, completing Section 1 requires identifying the worker with an A-number if they are providing an unexpired foreign passport with A-number as a standalone document, or when using an EAD. The A-number allows system users to check the validity period, confirm that the document is unexpired, and ensure that reemployment does not violate status conditions. When renewing an EAD or filing adjustment of status, the A-number helps USCIS link new requests to existing cases and avoid duplicate or conflicting authorizations.
Common Questions and Clarifications
Because A-numbers are long-lived identifiers, individuals often have questions about when and how they appear, and whether they change. The number is assigned once and does not change even if the card is renewed or replaced, unless there are very rare administrative corrections. It is not an indicator of how long a person has been in the United States, but rather a tool for recordkeeping and identity matching. It also does not, by itself, determine the duration of stay or work authorization; those are listed separately on the EAD and in USCIS case notes.
Frequently Asked Questions
- Does my A-number change when I renew my EAD? No; the A-number typically remains the same across renewals unless a correction is needed.
- Can I use my A-number instead of my SSN on job forms? Generally not; use your SSN on forms unless instructed otherwise by USCIS or an employer for specific immigration verifications.
- Is my A-number the same as my case number? No; the case number tracks a specific application, while the A-number identifies you across cases.
- Do all noncitizens have an A-number? Most individuals who appear in USCIS records receive an A-number, though some limited exceptions may apply.
Why the A-Number Matters for Long-Term Status and Recordkeeping
Because the Alien Registration Number links an individual to their immigration history, it plays a critical role in status updates, extensions, and adjustments. When applying for permanent residence or changing conditions of stay, USCIS relies on the A-number to pull the complete case file. Employers who maintain accurate records of A-numbers can more easily resolve discrepancies in employment eligibility verification or respond to audits. For individuals, safeguarding the A-number alongside other immigration documents reduces the risk of delays or errors when interacting with USCIS over time.
Summary
The Alien Registration Number on an EAD is the unique, lifelong identifier that connects a noncitizen to their immigration records and employment authorization. It appears on the card, in USCIS systems, and in agency correspondence, and is used to ensure accurate record matching and compliance checks. While it is separate from the EAD document number and from a Social Security Number, it works alongside these identifiers to support lawful employment and orderly immigration processes. Understanding where the A-number appears, how it is formatted, and when to use it can help individuals and employers manage authorization and verification more effectively.