Each United States passport is assigned a number that is attached to the bearer's name. This number is used to locate the passport holder, register at foreign embassies and check travel patterns. The number is found on the passport information page. The new passport card, issued for use between Canada, the United States, Mexico and the Caribbean, has the same number as the passport book of the user.
Open the passport to the second page; this is the user information page. Look across the top of the page for "United States of America" in large print.
Look at the line underneath "United States of America" and find "Passport No./No. du Passeport/No. de Pasaporte."
Look under the passport number line to find the passport's identifying number, a nine-digit code.
The new passport cards for North America have the passport number in the upper right-hand corner.