Country guide · Thailand

Thailand pays 4 baht a kilometre by the short and direct road, not by the road you took

The rate, and the chain it arrives by

The Revenue Code exempts transport expenses twice. s. 42(1) exempts what was spent "honestly, necessarily, exclusively and wholly in carrying out his duties". s. 42(2) exempts transport expenses and travelling per diem at the rates prescribed by the Government for its own officials.

The private sector reaches a per-kilometre figure through the second one. Ministry of Finance letter กค 0409.6/ว 42 (26 July 2007) sets the officials' flat rates — 4 baht per kilometre for a private car, 2 baht for a private motorcycle — and Revenue Department ruling กค 0702/1831 reads them across, exempting a flat vehicle allowance that does not exceed "อัตราค่าสูงสุดที่ทางราชการกำหนดจ่ายให้แก่ข้าราชการ".

Four for the car, two for the motorcycle. English-language summaries have had those inverted, and reading the motorcycle figure as the car figure halves every claim.

No logbook and no receipts — but a paper issued before you drive

Within that ceiling, no receipts are required. What is required is "หลักฐานการได้รับอนุมัติให้เดินทางไปปฏิบัติงาน" — documentation of approval to travel for work, naming the work to be done and the period.

It is issued before the journey. Two conditions ride with it: the private vehicle must be used for the whole journey to qualify at all, and any inability to do so has to be explained to and approved by a superior in advance.

So the substantive burden is a piece of paper that precedes the drive, plus s. 42(1)'s standard that the travel was genuinely and wholly for work.

The distance is prescribed, and it is not the distance you covered

This is the part that makes Thailand unlike every other country on this site. The rules governing the underlying official rate state, in ระเบียบ ข้อ ๑๑ as gazetted:

> "โดยให้คำนวณระยะทางเพื่อเบิกเงินชดเชยตามเส้นทางของกรมทางหลวงในทางสั้นและตรง ซึ่งสามารถเดินทางได้โดยสะดวกและปลอดภัย"

Compute the distance by the Department of Highways' route, short and direct, and one that can be travelled conveniently and safely. Where there is no Highways route, by another agency's route — a municipal one, for instance. Only where there is neither does the traveller certify the distance themselves.

And that rule reaches the private sector by import rather than by its own force. The Revenue Department's texts never mention distance; the ceiling rests on ruling กค 0702/1831's "ตามหลักเกณฑ์การเบิกจ่ายในลักษณะเหมาจ่าย" — under the officials' flat-rate rules — which is what carries ข้อ ๑๑ along with the figure.

Which way the error runs

Everywhere else, a recorded track is the better evidence: a GPS trace beats a number typed from memory, and the argument for automatic tracking is that it stops the claim being understated.

In Thailand it runs the other way. A track that took a detour, sat in traffic on a longer road, or wandered while the car was parked is larger than the claimable figure. Filing the recorded distance overstates the claim — and a claim that is too large is not a smaller problem than one that is too small.

The number to file is a routed shortest-path distance between the endpoints. A motorcycle's route is different again: riders may not use tolled roads, so the road available to a motorcycle is not always the road available to a car.

Two years, extendable to five — and an assessment you cannot appeal

For an individual filer there is no retention period in Thai law at all. The Revenue Code obliges an individual to make a daily record and to produce documents on a summons, never to keep them for a stated time. The Revenue Department's own FAQ tells individuals to keep documents five years and cites no provision, because there is none.

The effective horizon is the summons limit: s. 19, "ภายในเวลาสองปี นับแต่วันที่ได้ยื่นรายการ" — two years from filing, extendable by the Director-General "แต่ต้องไม่เกินห้าปี" on suspicion of evasion, and unlimited under s. 23 for anyone who never filed.

A company keeps its books five years from the closing date of the accounts under the Accounting Act B.E. 2543, but s. 8 of that Act lists who is bound and contains no natural person — so a Thai sole trader is outside it.

The sanction is the harshest here, and it is not money. Under s. 21, failing to comply with a s. 19 summons lets the officer assess "ตามที่รู้เห็นว่าถูกต้อง" — as they see fit — and "ห้ามมิให้อุทธรณ์การประเมิน": the assessment may not be appealed.

What failure costs

The allowance becomes assessable income.

Why an app rather than a notebook

Here the argument is not the usual one. A notebook and an app both record that a journey happened; what neither of them can do by hand, afterwards, is work out the short and direct Highways route between two places you visited in March.

DriveHub records each drive in the background with both endpoints, and for Thailand prices the routed shortest path rather than the recorded track — so rate × distance equals the amount on the row, and the figure on the report is the one ข้อ ๑๑ describes rather than the one the odometer saw. A motorcycle's route avoids tolled roads. The report also prints your own wording for the purpose, which the authorisation names as "ลักษณะงานที่ทำ", and the vehicle's owner, whom ข้อ ๑๑ requires to be the claimant.

The authorisation itself is not something it can produce. That is an employer document about permission, in the same family as Slovenia's potni nalog and Croatia's putni nalog, and it has to exist before the drive.

This page states what the Revenue Code, the Ministry of Finance letter and the officials' travel rules say, and names them so you can check. It is not tax advice. It can't account for your circumstances. Where money is involved, ask your accountant — and bring the approval.