What Is an A-Number?
An A-Number, or Alien Registration Number, is a unique identifying number the government assigns to many noncitizens to track their immigration records. An A-Number is a seven-to-nine-digit number, usually shown with an “A” in front, that identifies your immigration file and follows you across cases and agencies. You can find it on documents like your green card, immigration notices, and certain other records. Knowing your A-Number helps you track your case and communicate accurately with the government.
This guide explains what an A-Number is, where to find it, and why it matters. It connects to our guides on the USCIS online account number و checking your case status.
Need help locating or using your A-Number? Atlas Legal can assist. Contact our team with your questions.
الوجبات الرئيسية
- An A-Number is a unique Alien Registration Number.
- It identifies your immigration records across cases and agencies.
- It is usually shown with an “A” followed by digits.
- You can find it on documents like your green card and notices.
- Not everyone has one, but many noncitizens do.
What This Guide Covers
- What an A-Number is
- Its format
- Where to find it
- Who has one
- Why it matters
- Frequently asked questions
What an A-Number Is
An A-Number, short for Alien Registration Number, is a unique number the government assigns to many noncitizens. It serves as an identifier for a person’s immigration file and records.
Because it is unique to you, the A-Number allows the government to connect your records across different cases and agencies. It is one of the most important identifiers in the immigration system.
Its Format
An A-Number is typically shown as the letter “A” followed by a series of digits, usually seven to nine numbers. You may see it written with or without the “A,” and sometimes with spaces or other formatting.
Regardless of formatting, it refers to the same underlying number. When providing your A-Number, it is important to give it accurately so your records are matched correctly.
Where to Find It
Your A-Number appears on many immigration documents. Common places to find it include your green card and various immigration notices and records:
| المستند | Where the A-Number may appear |
|---|---|
| Green card | Often printed on the card |
| Immigration notices | On notices and correspondence about your case |
| Certain other records | On documents tied to your immigration file |
If you have received immigration documents, checking them is usually the easiest way to find your A-Number. Keeping it in a safe place is helpful.
Who Has One
Not everyone has an A-Number, but many noncitizens do, including permanent residents and people who have had certain immigration cases. It is assigned in connection with particular immigration processes.
If you have a green card or have been through certain immigration proceedings, you likely have an A-Number. Some people may not have one if they have not been assigned it through a relevant process.
Not sure whether you have an A-Number or where to find it? Ask Atlas Legal and we can help.
Why It Matters
The A-Number matters because it is how the government identifies and tracks your immigration records. Using the correct A-Number helps ensure your documents and cases are properly connected and that communications are matched to the right file.
When dealing with immigration agencies, checking your case, or filing forms, having your correct A-Number is important. An accurate A-Number reduces confusion and helps your case proceed smoothly.
When to Work With an Immigration Attorney
While the A-Number itself is straightforward, immigration cases that use it can be complex. Legal help is valuable when you cannot locate your A-Number, when your records seem inconsistent, when you are preparing filings, or when you need help managing a case. An attorney can help ensure your identifiers and records are correct. Outcomes depend on the facts of each case.
الأسئلة الشائعة
What is an A-Number?
An A-Number, or Alien Registration Number, is a unique number the government assigns to many noncitizens to identify their immigration file and records. It is usually shown as the letter “A” followed by seven to nine digits. Because it is unique to you, it connects your records across different cases and agencies. You can find it on documents like your green card and immigration notices, and it is an important identifier in the system.
What does an A-Number look like?
An A-Number is typically shown as the letter “A” followed by a series of digits, usually seven to nine numbers. You may see it written with or without the “A,” and sometimes with spaces or other formatting, but it refers to the same underlying number. When providing your A-Number, it is important to give it accurately so your immigration records are matched correctly and there is no confusion.
Where can I find my A-Number?
Your A-Number appears on many immigration documents. Common places include your green card, which often has it printed on the card, and various immigration notices and correspondence about your case, as well as certain other records tied to your file. If you have received immigration documents, checking them is usually the easiest way to find your A-Number. Keeping it in a safe place is helpful for future use.
Does everyone have an A-Number?
No. Not everyone has an A-Number, but many noncitizens do, including permanent residents and people who have had certain immigration cases. It is assigned in connection with particular immigration processes. If you have a green card or have been through certain immigration proceedings, you likely have one. Some people may not have an A-Number if they have not been assigned it through a relevant process.
Why is my A-Number important?
Your A-Number is how the government identifies and tracks your immigration records. Using the correct A-Number helps ensure your documents and cases are properly connected and that communications are matched to the right file. When dealing with immigration agencies, checking your case, or filing forms, having your correct A-Number is important, because an accurate number reduces confusion and helps your case proceed smoothly.
Is an A-Number the same as a case number?
No. An A-Number identifies you and your overall immigration file, while a case or receipt number generally identifies a specific application or petition. You may have one A-Number but multiple case numbers over time for different filings. Because they serve different purposes, it is important to use the right number in the right context. If you are unsure which number to provide, checking your documents or getting help can clarify it.
What if I cannot find my A-Number?
If you cannot find your A-Number, start by checking your immigration documents, such as your green card and any notices, where it commonly appears. If you still cannot locate it, an attorney or the relevant agency may be able to help you identify it based on your records. Because the A-Number is important for your case, taking the time to locate the correct one, with help if needed, is worthwhile.
Can my A-Number change?
Generally, your A-Number is a stable identifier that stays with your immigration file over time, rather than changing from case to case. This is what allows it to connect your records across different proceedings and agencies. In unusual situations, discrepancies can arise, which is why using the correct number consistently is important. If you notice conflicting A-Numbers on your documents, it is worth having the issue reviewed to ensure your records are accurate.
خلاصة القول
An A-Number is a unique Alien Registration Number that identifies your immigration records across cases and agencies, usually shown as an “A” followed by digits. You can find it on documents like your green card and notices. Using the correct A-Number helps your case proceed smoothly. Each case depends on its own facts.
If you need help with your A-Number or immigration records, Atlas Legal Immigration Law can assist. Reach us at 1750 E Golf Rd Ste 214, Schaumburg, IL 60173, call (+1) 872 382 2762, or email info@theatlaslegal.com. Learn more on our services page.
Reviewed by the Atlas Legal Immigration Law editorial team. Last reviewed on July 28, 2026.
Sources
- U.S. Citizenship and Immigration Services, USCIS Glossary
- U.S. Citizenship and Immigration Services, البطاقة الخضراء
- U.S. Citizenship and Immigration Services, USCIS Contact Center
This article is provided for general informational purposes only and does not constitute legal advice. Immigration laws, government fees, policies, and processing times may change. Reading this article or contacting Atlas Legal does not by itself create an attorney-client relationship. The outcome of any immigration matter depends on its individual facts and circumstances.
