DictionaryIdentity and taxes

A-Number: what it means

The A-Number is the alien registration number. According to the Justice Department's Executive Office for Immigration Review (EOIR), it begins with the letter A, followed by eight or nine digits, and is printed on Department of Homeland Security (DHS) and EOIR letters.

In Spanish it is

Número A (A-Number)

Also written as: A-Number · alien registration number · A number

A pregnant woman takes a video appointment on a tablet at her kitchen table.

Verified on October 17, 2026

2 official sources

See the whole dictionary

The full explanation

It can be used to look up the status of an immigration court case in EOIR's automated system, which shows only basic information. The documents the court issues are the only official decisions in the case.

An example

Carmen receives a letter from the immigration court with a number that begins with A. She uses that number in EOIR's official system to see the date of her next hearing.

You will see it in…

Letters from DHS and the immigration court
EOIR's automated case information system
Immigration forms that ask for your registration number

Words that go with it

You will rarely see this word alone. These are the ones that show up with it on the same papers.

Still confused by a paper?

A HUD-approved housing counselor can walk you through it. Agencies usually charge little or nothing, many work in Spanish, and they do not sell you anything.

What a housing counselor does See free help

Official sources

We sum up what these official sources say, in plain words. We add no rules they do not state; when a rule changes, the definition and its date change.

1. U.S. Department of Justice, EOIR · Customer Service Initiatives (automated case information) (external site) · in English · Verified on October 17, 2026
2. U.S. Department of Justice, EOIR · Automated Case Information (external site) · in English · Verified on October 17, 2026