Thailand Passport Number

Detects Thai passport numbers issued by the Department of Consular Affairs, Ministry of Foreign Affairs of Thailand. Documented formats are one letter followed by six digits (older series, e.g. A123456), two letters followed by six digits (e.g. AA123456), or two letters followed by seven digits (current e-passport series, e.g. AA1234567, nine characters total matching the MRZ document-number field). Note: the legacy A123456 / AA123456 forms are documented by a single source (Thai Wikipedia); the current AA1234567 form is corroborated independently via the MRZ document-number field.

Type: regex
Engine: universal
Confidence: medium
Confidence justification: Medium confidence: short letter-prefixed alphanumeric runs (1-2 letters + 6-7 digits) are common in order codes, bookings and other reference numbers, so corroborating passport keywords are required on every tier. No tier fires on the bare value alone (D1 identifier convention).
Jurisdictions: th
Regulations: PDPA (TH)
Frameworks: ISO 27001, ISO 27701
Data categories: pii, government-id
Scope: narrow
Risk rating: 8
Platform compatibility: Purview: Compatible, GCP DLP: Compatible, Macie: Compatible, Zscaler: Compatible, Palo Alto: Compatible, Netskope: Unsupported

Pattern

\b(?:[A-Z]\d{6}|[A-Z]{2}\d{6,7})\b

Corroborative evidence keywords

Thai passport, passport number, travel document, หนังสือเดินทาง, เลขที่หนังสือเดินทาง

Proximity: 300 characters

Should match

Thai passport number AA1234567 was recorded on the arrival card — Current e-passport series, two letters and seven digits
Passport No.: A123456 (old series) was replaced upon renewal — Older series, one letter and six digits
หนังสือเดินทางเลขที่ AB123456 ออกโดยกระทรวงการต่างประเทศ — Two letters and six digits with Thai label

Should not match

Order code ABC123456 shipped from the warehouse yesterday — Three letter prefix is not a documented series
Ticket A12345 was closed by the support team — Only five digits after the letter is too short
Booking AA12345678 confirmed for the tour group — Eight digits after two letters is too long

Known false positives

One or two letters followed by 6-7 digits is a common shape for order numbers, bookings, and product references. Mitigation: Every tier requires corroborating passport keywords within the proximity window; there is no bare value-only tier.
Hong Kong identity card numbers written without the bracketed check digit (e.g. A123456) structurally overlap the 1-letter form. Mitigation: Passport-specific keyword evidence (Thai-language and passport terms) separates travel-document context from HKID context, which hk-identity-card covers with its own keywords.
Sample passport numbers in visa application guides or templates may match the labelled form. Mitigation: The high and medium tiers apply the template-exclusion NOT-group to suppress sample and documentation content.