A used-car lot in Nakhon Ratchasima keeps a Word template on the office PC. It has been edited perhaps forty times. Someone re-types the mileage into it from the vehicle record, prints two copies, and the buyer signs one.
That template is doing regulated work, and almost nobody selling software to that lot describes it that way.
Thai used-car selling is governed by three separate announcements issued by two different committees. Miss that structure and you will search the wrong place and conclude, wrongly, that the rules do not exist. Nearly every article still cites a labelling rule that was repealed in 2568.
The three instruments, and what each one demands
| Instrument | Committee | What it forces you to produce |
|---|---|---|
| ประกาศฯ ควบคุมสัญญา ขายรถยนต์ใช้แล้ว พ.ศ. ๒๕๖๒ | คณะกรรมการว่าด้วยสัญญา | A sale contract carrying set particulars, including mileage |
| ประกาศฯ หลักฐานการรับเงิน พ.ศ. ๒๕๕๐ | คณะกรรมการว่าด้วยสัญญา | A receipt at the moment money changes hands, without a blanket forfeiture clause |
| ประกาศคณะกรรมการว่าด้วยฉลาก พ.ศ. ๒๕๖๘ | คณะกรรมการว่าด้วยฉลาก | A label on the car that says ไม่มี where nothing applies |
Two come from the Contract Committee and one from the Labelling Committee. That's why this is hard to find.
One: the contract is controlled, and mileage is in it
ข้อ ๑ of the 2562 announcement makes ธุรกิจการขายรถยนต์ใช้แล้ว a contract-controlled business. Scope is sales to an individual buying for personal use; auctions and parts-out businesses are expressly outside it.
ข้อ ๓ then lists what the contract must contain: brand, model, year, colour, engine and chassis numbers, engine size, and registration number. It also requires fitted equipment, ระยะทางที่ได้ใช้แล้ว in kilometres or miles, the price, and any เงินจอง, เงินมัดจำ or เงินดาวน์ taken, with the date received. Thai language, characters no smaller than two millimetres, no more than eleven characters to the inch.
This is the part that matters most commercially. ข้อ ๓(๔.๓) gives the buyer a right to rescind if the delivered car's particulars don't match the contract, including the distance already travelled. ข้อ ๓(๕) then requires the dealer to return everything received within fifteen days.
That's a statutory answer to odometer tampering. It doesn't require proving fraud, only a mismatch between two documents.
ข้อ ๔ separately bans contract terms letting the dealer forfeit money unless the consumer is the party in breach.
Two: the deposit slip most lots use is unlawful on its face
The 2550 receipt announcement requires a receipt handed to the buyer immediately on receiving any payment, whole or partial. For a partial payment the slip must show the mileage, any ภาระผูกพัน on the car, and the registered owner's name.
ข้อ ๕ then states what the receipt must not contain. First on that list: ข้อความที่ให้สิทธิผู้ประกอบธุรกิจยึดเงินทั้งหมดไม่ว่ากรณีใด ๆ, wording that lets the business keep the whole amount in any circumstance.
Walk into a lot in Chiang Mai or Bangkok and you'll likely see the same stamp: เงินจองไม่คืนทุกกรณี. It's close to standard across the trade, and it's exactly the wording ข้อ ๕ bans. A 20,000 THB deposit held under that stamp is already sitting on an unlawful receipt.
Three: the labelling rule everyone cites was repealed
This is where published Thai guidance is most consistently wrong. ประกาศคณะกรรมการว่าด้วยฉลาก ฉบับที่ ๓๕ (พ.ศ. ๒๕๕๖) is the version cited in nearly every blog post, vendor page and forum answer on the subject.
It was repealed. The replacement was published in the Royal Gazette on 1 October 2568 and took effect 180 days later, so it has been in force since roughly the end of March 2026.
The substantive change is small to describe and large in practice. Under the old rule, several disclosures were qualified with (ถ้ามี) (if any). A dealer with nothing to declare could simply leave the field blank. Under the new rule the dealer must affirmatively print ไม่มี for outstanding encumbrances, the absence of a service book, the absence of accident history, and the absence of a warranty.
Silence is now a defective label rather than a neutral one. Flood history must also specify the water level reached: floor, seat, dashboard, or fully submerged. The announcement adds an EV block.
One provision moved the other way: the minimum character height dropped from one centimetre to two millimetres.
What this means for the software
Every one of those artifacts comes out of the vehicle record. The feature that looks like a typing shortcut is the compliance layer.
Four systems come up repeatedly in Thai dealer software searches, and they split cleanly here. BossCarSoft is the only one documenting สคบ. contract form printing generated straight from the vehicle record, plus finance submission tracking for hire-purchase deals. That's the one I'd trust with the mileage field. Suparat MCS is the only one documenting a vehicle registration, insurance and พ.ร.บ. module, sold separately from showroom and parts. Useful if registration paperwork is your bottleneck, dead weight if it isn't. COMMACAR drives a public storefront off the same stock records but documents no contract printing, a real gap for a Bangkok lot relying on it alone. Dealer Vision reports across sales, inventory, finance and service performance: useful for a franchise dealer juggling branches, overkill for a single lot in Nakhon Ratchasima or Chiang Mai.
The practical test for a vendor demo is short. Ask it to produce the sale contract from a vehicle record, then check whether the mileage on the printed contract matches the field used everywhere else. If a human re-types it by hand, ข้อ ๓(๔.๓) is a live exposure sitting in a Word file, and on a 400,000 THB car, that's real money at risk.
The hire-purchase side is a fourth instrument again. The 2565 announcement caps used-vehicle hire-purchase interest at 15% a year on an effective basis, and it binds the lender's contract, not the lot's sale contract. It's reviewable every three years, and that window falls in 2026.
What we could not verify, and are not going to assert
This subject is full of confidently repeated figures with nothing behind them.
- We publish no penalty amounts. Figures circulate for these offences and the ones we checked disagreed with each other. Read the current consolidated Act rather than a news article, including a 2019 amendment that changed at least one figure.
- No Thai law names การกรอไมล์ as a standalone offence, and we found no court citation for a prosecution. The reachable remedy is the 2562 rescission right above, which is stronger because it needs a document mismatch rather than proof of intent.
- Nothing in these three announcements says a finance decline obliges the dealer to refund a deposit. All three were read in full. Buyers widely believe it does. Whether a decline counts as the consumer being in breach gets decided case by case. A lot that promises a refund on decline anyway is closing a gap the law leaves open, nothing more.
- Whether the 2562 and 2550 announcements are themselves still current has not been re-verified. The labelling announcement was replaced with no fanfare, and nothing guarantees the others were not. Check the OCPB law index before relying on any of this commercially.
Every Gazette citation above was read from the source PDF rather than from a secondary summary.