Home›Validators›Finance & Global IDs›US Passport Number Validator

US Passport Number Validator

Finance & Global IDs

Validate a US passport number format instantly. Checks the correct 9-character alphanumeric structure used on US passport books and cards free.

Reviewed by the thecalcu.com team · Last updated July 9, 2026

What is a US Passport?

The US Passport Number Validator checks whether a US passport number follows the correct 9-character alphanumeric format used on US passport books and cards. It verifies the length, confirms the number starts with a letter (as all US passport numbers do), and checks that only valid characters (A–Z, 0–9) are present.

US passport book numbers are 9 characters: typically a letter followed by 8 digits (e.g. A12345678), though some newer books may begin with two letters. US passport card numbers also follow the 9-character format and start with the letter C. Both are issued by the US Department of State and appear on the data page of the document and in the Machine Readable Zone (MRZ).

The format check is a useful first-pass filter in travel, immigration, and identity verification forms, catching transpositions, short entries from partial copies, and entries made from OCR-scanned documents that introduced incorrect characters.

What this validator checks: exactly 9 characters, first character is a letter (A–Z), all remaining characters are letters or digits (no spaces, hyphens, or special characters).

What it does not check: Whether the passport was actually issued, is currently valid, or belongs to a specific person. Format validation only, the State Department does not expose a public passport verification API.

For related US identity document validation, see the SSN Validator and DUNS Number Validator.

All validation is client-side. No data is transmitted.

Why Use a US Passport Number Validator?

Travel booking platforms, visa application portals, hotel check-in systems, and airline check-in flows all collect passport numbers. A format validator at the input level catches the most common entry errors: wrong length (8 characters from an Indian passport), spaces included from a copy-paste, or lowercase letters from a form that did not enforce uppercase.

Travel SaaS use case: An Indian travel technology company building a flight booking platform for US passport holders needs to validate passport number format before submitting to an airline API. An invalid format (wrong length or lowercase characters) causes an API rejection. A client-side validator prevents this without an API call.

Immigration portal use case: A US immigration law firm's client portal collects passport numbers for visa petition preparation. A format validator flags entries that are clearly wrong (7 characters, digits-only, or containing special characters) before they reach the attorney's case management system.

Who Should Use This Validator?

Travel technology developers building booking platforms, visa application portals, or airline check-in flows that collect US passport numbers.

Indian software teams building US-market travel, hospitality, or immigration products where passport number validation is a form requirement.

HR and immigration compliance teams at companies sponsoring US work visas who collect passport data from employees.

Hotel and hospitality operators digitising guest registration forms that require passport number capture for non-US guests staying in the US.

What Insights Does the US Passport Number Validator Give You?

A valid result shows the passport number and a likely document type: numbers starting with C are flagged as likely passport cards (valid for land/sea travel only, not international air travel). All other letters indicate a passport book.

An invalid result specifies the failure: wrong character count, first character is a digit (not a letter), or invalid characters present. The most common error is entering an 8-character Indian passport number in a US passport field.

How to use this US Passport calculator

  1. Enter the passport number in the input field, 9 characters, uppercase letters and digits.
  2. Check the Valid/Invalid badge, updates instantly.
  3. Read the details, character count and likely document type (book or card).
  4. If entering on behalf of someone: verify against the physical document to avoid OCR transcription errors.
  5. Note: passport card numbers (starting with C) are not valid for international air travel.
  6. Related tools: use the SSN Validator for Social Security numbers.
Show formula & methodology ↓Show less ↑

Formula & Methodology

Format rules:
- Exactly 9 characters
- First character: uppercase letter (A–Z)
- Remaining 8 characters: uppercase letters (A–Z) or digits (0–9)
- Regex: /^[A-Z][A-Z0-9]{8}$/

Likely document type by first character:

| First character | Likely document |
|---|---|
| C | US Passport Card |
| Other letter | US Passport Book |

Valid and invalid examples:

| Input | Valid? | Note |
|---|---|---|
| A12345678 | ✓ | 9 chars, starts with letter |
| C98765432 | ✓ | Likely passport card |
| AB1234567 | ✓ | Two letters, valid format |
| A1234567 | ✗ | Only 8 characters |
| 123456789 | ✗ | Starts with digit |
| A1234567! | ✗ | Invalid special character |

Related Tools

You may also find these useful: US Driver's License Validator.

Frequently Asked Questions

What is the format of a US passport number?
US passport book numbers are 9 characters long, consisting of uppercase letters and digits. Most passport books start with a single letter followed by 8 digits (e.g. A12345678), though some newer books may start with two letters. US passport cards (the wallet-sized alternative to the passport book) start with the letter C. Both documents use 9-character alphanumeric numbers with no spaces or hyphens.
Where is the passport number on a US passport?
On a US passport book, the passport number is printed in the upper right corner of the photo page (page 2) and also in the Machine Readable Zone (MRZ), the two lines of alphanumeric text at the bottom of the data page. On a US passport card, the number is on the front of the card. The number begins with a letter and is always 9 characters.
What is the difference between a US passport book and a passport card?
A US passport book is accepted for all international travel by air, land, and sea. A passport card is a wallet-sized alternative that is valid only for land and sea travel to Canada, Mexico, the Caribbean, and Bermuda, not for international air travel. Passport card numbers start with the letter C. Both contain the holder's full name, date of birth, and photograph, and both expire after 10 years for adults (5 years for children under 16).
Does this validator confirm the passport is valid and not expired?
The validator checks format only: 9 characters, starting with a letter, containing only uppercase letters and digits. It cannot access the US State Department database to confirm the passport was issued, is currently valid, or has not been reported lost or stolen. Passport authentication for travel purposes is handled by border control authorities using the Machine Readable Zone and chip data.
Can I use a US passport number to verify someone's identity online?
No, the US passport number is not publicly searchable in any government database. The State Department does not provide a public API for passport number verification. For identity verification, use identity verification services that compare a passport scan against government databases with the holder's consent. This tool is for format validation only, not identity verification.
Is my passport number data stored when I validate it?
No, all validation runs entirely in your browser. The passport number is never sent to any server, stored, or logged. The tool works offline once loaded. Best practice: do not enter real passport numbers in web-based tools unless you are specifically using an authorised identity verification service.
How is a US passport number different from an Indian passport number?
An Indian passport number is 8 characters: 1 uppercase letter followed by 7 digits (e.g. A1234567). A US passport number is 9 characters, typically 1 letter followed by 8 digits. Both start with a letter and contain only alphanumeric characters. An Indian IT team building a travel booking platform would need separate format validators for each country's passport number format.
How do I use the US Passport Number Validator?
Enter the passport number in the input field, 9 characters, letters and digits only. The validator checks the length, confirms the first character is a letter, and verifies that only valid alphanumeric characters are present. The Valid/Invalid badge updates instantly. The details panel shows the likely document type (passport book or passport card) based on the first character.
What does it mean if the passport number starts with C?
US passport card numbers start with the letter C. Passport book numbers typically start with other letters. If a passport number starting with C is entered, the validator flags it as likely a passport card, which is valid for land and sea travel to Canada, Mexico, the Caribbean, and Bermuda, but not for international air travel. If you are booking an international flight and need to enter a passport number, ensure it is from a passport book, not a card.
Can a US passport number contain the letter O (oh) or I (eye)?
US passport numbers use uppercase letters and digits in their 9-character format. The exact character set allowed is not publicly documented to the same precision as identifiers like the VIN. In practice, the first character is always a letter (A–Z). If you encounter issues with a specific passport number, verify the number digit by digit against the physical document, OCR errors on scanned documents sometimes confuse 0/O and 1/I.
How do I apply for a US passport if I need one for international travel?
US citizens apply for passports through the US State Department. First-time applicants must apply in person at a passport acceptance facility (many post offices, libraries, and government offices). Renewals can typically be done by mail. The standard processing time is 6–8 weeks; expedited service takes 2–3 weeks. Fees vary: approximately $130 for a passport book, $30 for a card, plus a $35 execution fee for new applicants.
Also known as
US passport number checkvalidate US passportAmerican passport formatpassport number validatorcheck passport number