A travel document number is the unique serial code printed on a specific passport, visa, green card, or similar credential that authorizes international travel or proves immigration status. On a U.S. passport book, it’s a letter followed by eight digits in the upper-right corner of the data page. Every document has its own number, the number belongs to that physical document rather than to you, and it changes whenever the document is replaced.
What the Number Actually Identifies
Treat a travel document number as the serial number of one particular booklet, card, or sticker. A passport has one. A visa foil has a separate one. A green card has yet another. Governments use the number to verify that specific document, not to identify you as a person, which is why you’ll accumulate several different travel document numbers across your lifetime as old credentials expire.
It is not your Social Security number, and it is not your alien registration number (A-number). Those stay with you. When a form asks for a travel document number, it wants the number printed on whichever credential you’re presenting.
Finding It on a U.S. Passport
On a U.S. passport book, the passport number sits in the top-right corner of the data page, the page with your photo and biographical details. The same number is repeated at the bottom of every interior page. The format is one letter followed by eight digits.1Travel.State.Gov. Information About the Next Generation U.S. Passport
A U.S. passport card carries its own number, printed on both the front and back. That number is separate from the passport book number, so if you hold both credentials you have two different travel document numbers. Use the one printed on whichever document you’re actually traveling or applying with.
Finding It on a Visa
A U.S. visa sticker (also called a visa foil) is affixed inside your passport. The visa foil number is printed in red ink near the lower-right corner of the sticker. It’s usually eight digits, though older visas may show a letter followed by seven digits.2U.S. Customs and Border Protection. APIS Travel Document Reference
Don’t confuse this with the passport number. They are two different numbers on two different credentials, even though the visa is glued inside the passport book. A field labeled “visa number” wants the red number on the sticker. A field labeled “passport number” wants the number on the data page.
Finding It on a Green Card
A permanent resident card (Form I-551) has a 13-character card number: three letters followed by ten digits. On cards issued after May 2010, it appears in the machine-readable zone on the back. Older cards may display it on the front, and some very old versions don’t show a card number at all.
The green card also shows a USCIS number (your A-number) on the front. These are not the same. The card number identifies that particular piece of plastic. The A-number identifies you in the immigration system and stays the same when the card is replaced.
The Number Changes Every Time You Get a New Document
This trips people up. When you renew or replace a passport, the new book gets an entirely new passport number.3Travel.State.Gov. Frequently Asked Questions About Passport Services The old number is retired. The same applies to reissued visas and replacement green cards.
Anything tied to the old number needs updating. An ESTA travel authorization is linked to one specific passport. Get a new passport, and you need to submit a fresh ESTA under the new number; there’s no way to edit the passport field on an existing ESTA.4U.S. Customs and Border Protection. Apply or Change Information in the Electronic System for Travel Authorization (ESTA) Airline reservations booked under an old passport number need the same treatment: update the booking with the new number before you fly.
When You’ll Be Asked for It
Airline Bookings and Check-In
Airlines flying to or from the United States must transmit passenger travel document numbers to Customs and Border Protection through the Advance Passenger Information System.5eCFR. 19 CFR 122.49a – Electronic Manifest Requirement for Passengers Onboard Commercial Aircraft Arriving in the United States That’s why the airline collects your passport number when you book and again at check-in.
Visa and Immigration Applications
Almost every immigration form asks for a travel document number. Visa applications want your current passport number. Adjustment-of-status petitions, work permit applications, and travel authorization requests include fields for the document numbers on whichever credentials you hold.
ESTA
Travelers from Visa Waiver Program countries need an approved ESTA before flying to the United States. The application requires your passport number, and the approval is locked to that specific passport.6U.S. Customs and Border Protection. Frequently Asked Questions About the Visa Waiver Program (VWP) and the Electronic System for Travel Authorization (ESTA)
Form I-9 at a New Job
When you start work in the United States, your employer completes Form I-9. If you present a foreign passport, the employer records the document number and expiration date in Section 2. Employees who attest they are authorized aliens also enter their foreign passport number and country of issuance in Section 1.7U.S. Citizenship and Immigration Services. Instructions for Form I-9, Employment Eligibility Verification
What Happens If the Number Is Wrong
A mismatch between the number on your reservation or application and the number on the physical document you present causes problems at several points. At check-in, the airline’s system may flag the discrepancy against CBP data. At the gate or the border, an officer comparing the document to the transmitted record will see it too. Expect delays, extra screening, or in some cases denied boarding.
Airlines that carry improperly documented passengers to the United States face civil penalties under the Immigration and Nationality Act,8Federal Register. Mitigation of Carrier Fines for Transporting Aliens Without Proper Documents which is why carriers verify document details aggressively before departure.
If you catch a wrong number on an existing booking, contact the airline right away. Most carriers let you correct passport details online or through customer service. For an immigration form, correction depends on the form and how far along it has been processed; fixing errors before submission is always easier than fixing them afterward.
If the Document Is Lost or Stolen
Losing a passport means losing that travel document number for good. A replacement will carry a completely new number, and the old one is canceled in government systems. Report a lost or stolen U.S. passport using Form DS-64, and apply for a replacement in person on Form DS-11.9United States Department of State. Replacing a Lost or Stolen Passport (DS-11/DS-64) The current cost for an adult replacement passport book is $165, made up of a $130 application fee and a $35 execution fee.10Travel.State.Gov. Passport Fees
Once the new passport arrives, update every record that references the old number: airline reservations, ESTA authorizations, visa applications in progress, and employer records. A canceled passport number still sitting on your itinerary can create real problems at the border.