# Detect tampered and deepfake Thai National ID Card > The Thai national ID card is the identity document for Thai nationals, issued by the Department of Provincial Administration as a bilingual smart card, and it is the default identity anchor for banking and eKYC. Its thirteen-digit number ends in a computed check digit, so fabricated numbers fail arithmetic, and the Buddhist Era dates give a second consistency test. **Canonical URL:** https://tampercheck.ai/documents-support/thailand_id_card **API document class:** `thailand_id_card` **Last updated:** 2026-10-04 --- ## What a genuine Thai ID Card contains The number runs thirteen digits, printed in a one, four, five, two, and one grouping, with a category digit first, a registration office code, a personal number, and a final checksum digit. The card prints name and date of birth in Thai and English, religion, address, issue and expiry dates, photograph, and a seal. The back carries a laser code of twelve alphanumeric characters. Thai dates use the Buddhist Era, which runs five hundred and forty-three years ahead of the Gregorian year, so a Thai date and its English line must agree once converted. The laser code is an inventory code unrelated to the holder, so only its format can be tested, and the number does not encode a birth date. ## How Thai ID Card forgeries are made ### Check-digit recomputation Multiply the first twelve digits by weights from thirteen down to two, sum them, and derive the final digit with a mod-11 rule. A number failing it was invented, which is among the cheapest structural checks. ### Buddhist Era conversion Subtract five hundred and forty-three from the Thai year and compare it with the English date line. A conversion that disagrees with the printed Gregorian birth date shows an edited field. ### Laser code pattern The back code follows a two letters, one digit, seven digits, two digits pattern, twelve characters in all. A code outside that pattern is malformed, though it cannot be matched to the front. ### Photo and data patching Substituted portraits and edited address or date lines leave cut-line edges, resolution steps, and font passes, and Thai script makes baseline breaks easy to localise. ### Chip and layout conformance The smart card carries a chip. A chip area printed as a flat graphic suggests a reprint rather than an issued card. ## What TamperCheck checks on a Thai ID Card TamperCheck runs 200+ forensic checks across three layers and returns a risk score from 0 to 100 with plain-English findings tied to specific regions of the document. These three carry the most weight on this document class. ### Portrait substitution and face-swap analysis The document is isolated from whatever it was photographed on, then the portrait region is assessed against the card surface around it. A pasted or generated face rarely matches the substrate it was placed onto. ### Date and validity consistency Issue, expiry, and period dates are checked against one another and against the file's own creation metadata, which catches backdating and validity extension. ### Reference and document number checks Document, account, and reference numbers are checked for issuer format conformance and against every other place the same value appears on the page. ### And many more checks The three above are the layers that carry the most weight on a Thai ID Card. Every upload runs the full suite of 200+ checks regardless of document class, spanning file structure and metadata, pixel-level forensics, font and text rendering, optical and print characteristics, provenance signals, AI-generation signatures, and many more checks. ## Who verifies a Thai ID Card, and why Thai banks, e-wallets, and eKYC platforms. In each case the document is being used to unlock money, access, or a legal status, which is exactly what makes it worth forging. ## How to verify a Thai ID Card in 4 steps 1. **Photograph the document.** Capture the front and back flat at full resolution so the number, Thai text, and laser code survive close analysis. 2. **Validate the number.** Apply the mod-11 check digit rule to the thirteen digits. A failure marks a fabricated number regardless of print quality. 3. **Convert and cross-check dates.** Convert Buddhist Era years to Gregorian and compare against the English date line, then check the laser code format on the back. 4. **Run a forensic check on the file.** TamperCheck runs 200+ forensic checks including check-digit recomputation and patch detection, returning a risk score from 0 to 100 with findings tied to specific regions of the image. ## Frequently asked questions ### How is the Thai ID check digit computed? Digits one to twelve are multiplied by weights from thirteen down to two, summed, and the check digit is derived from the sum with a mod-11 rule. A failing number was typed rather than issued. ### Does the Thai ID number encode a birth date? No. It encodes a category, a registration office, and a personal number, so the birth date has to be checked through the printed Thai and English lines instead. ### Why do Thai dates look five centuries ahead? Thai documents use the Buddhist Era, which is the Gregorian year plus five hundred and forty-three. A Buddhist Era year on its own is not a flag. ### How does TamperCheck verify a Thai ID card? TamperCheck recomputes the check digit, converts Buddhist Era dates against the English line, tests the laser code format, and inspects the portrait and text for patching. Uploads run through a single REST endpoint, are processed ephemerally and not stored, and findings tie to specific regions. ## Related document types - TamperCheck Forensic Report: https://tampercheck.ai/documents-support/forensic_analysis_report - Unknown: https://tampercheck.ai/documents-support/unknown --- Try TamperCheck now: https://tampercheck.ai/dashboard · Docs: https://tampercheck.ai/docs · Pricing: https://tampercheck.ai/pricing