What is an A-number?

Alien Number: the number U.S. immigration authorities use to find a person in their system. It’s usually 9 digits, often with the letter A in front. In the app you can enter 8 or 9 digits: a zero is added to 8 digits automatically.

Where to find it: the I-862 Notice to Appear, your work permit card (EAD), and the upper right corner of USCIS notice I-797.