The US passport number format is nine characters long, printed in the upper-right corner of the data page inside your passport book. Books issued before 2021 use nine digits. Books issued under the Next Generation Passport program, starting in 2021, use one letter followed by eight digits. Passport cards use their own separate format and their own separate number.
What the Nine Characters Look Like
Every US passport number is exactly nine characters, matching the international standard set by the International Civil Aviation Organization for machine-readable travel documents. That same nine-character string appears twice on the data page: once in plain text at the top right, and again encoded in the machine-readable zone at the bottom, where border systems scan it.
If your passport was issued before 2021 and is still valid, your number is nine digits with no letters. When that book expires and you renew, the replacement will come with the newer alphanumeric format: a single letter in the first position, then eight digits. The switch dramatically expanded the pool of available combinations, which matters when millions of new passports go out every year.
Passport Card Numbers Are Different
Passport cards use a separate scheme. A card number starts with the letter “C” followed by eight digits, so it’s easy to tell apart from a book number at a glance. If you hold both a book and a card, they carry two completely different numbers, even if you applied for both at the same time.
The card only works for land and sea travel between the United States and Canada, Mexico, Bermuda, and the Caribbean. It’s not valid for international air travel. So if a form asks for the number of the document you’ll actually travel on, make sure you’re copying from the right one.
Passport Number vs. Passport Book Number
These are two different things, and some forms ask for both. Your passport number is the nine-character string in the upper right of the data page. The passport book number, sometimes called the inventory control number, is a separate identifier that tracks the physical booklet itself and is printed elsewhere in the book.
The distinction shows up most often on visa paperwork. The DS-160 nonimmigrant visa application has separate fields for each. If your passport doesn’t display a visible book number, the form lets you select “Does Not Apply.” Not every country prints one, and the location varies by issuing country. For a US book, don’t put the same nine characters in both fields.
Where to Find the Number
On a passport book, look at the top right corner of the data page. That’s the page with your photo, name, and date of birth. On Next Generation books, the number is also reprinted at the bottom of every page throughout the booklet.
It appears one more time in the machine-readable zone, the two lines of text and symbols at the bottom of the data page. In that zone, the number occupies the first nine positions of the second line, followed immediately by a check digit that automated systems use to confirm the scan was read correctly.
On a passport card, the number is printed on the front and repeated on the back. When you’re copying it onto something like an I-9 for employment verification or a DS-82 for renewal, copy it exactly as printed, including the leading letter. Confusing a letter for a similar-looking digit, or transposing two characters, can hold up processing.
Your Number Changes Every Time You Renew
A passport number is tied to the physical document, not to you. Every new passport, whether it’s a renewal, a replacement, or a first-time application, comes with a new number, and the old number is permanently retired. That’s different from a Social Security number, which stays with you for life.
Practically, that means older records referencing your previous passport, such as visa stamps, airline reservations, and government filings, won’t match your new book. If you’re renewing close to an international trip, check that your airline booking reflects the number on the passport you’ll actually carry.
Reporting a Lost or Stolen Passport
Once you report a passport lost or stolen using Form DS-64, the State Department enters that number into the Consular Lost or Stolen Passport System and permanently invalidates it. Anyone who tries to use it at a port of entry, including you if the book later turns up, can be detained. There’s no way to reactivate an invalidated number; you have to apply for a new passport, and it will come with a new number.