Thailand's mileage rate: 4 baht a kilometre, and what it is not

Milometry 1.2.0 reads in Thai and carries a Thailand scheme. The second of those needs explaining more than the first, because Thailand does not have what Britain, Germany or the Netherlands have: a published per-kilometre figure that a private employer can pay tax free. What it has is a government reimbursement rate, and the app uses it honestly for what it is.

The figure, and where it comes from

When a Thai civil servant uses their own car on official business, the state reimburses them at 4 baht a kilometre. A motorcycle is 2 baht. The figures are set by the Ministry of Finance under the Official Travel Expenses Regulation B.E. 2550 (2007), in a letter of 26 July 2007, and they have not changed since. The Secretariat of the Prime Minister's manual on official travel expenses quotes both figures on page 12 and cites that letter, and it is the source the app links to.

Two things about the figure are worth noticing. It is old: nineteen years without a change, against a petrol price that has roughly doubled. And it is flat, with no threshold and no annual ceiling, which makes the arithmetic simple. Drive 100 km on official business in your own car and the state owes you 400 baht.

What it is not

The Thai rate is government compensation for its own officials. It is not a rate a private employer is obliged to pay, and it is not an amount a private employee can claim as tax relief. The Revenue Department's rulings on mileage paid by companies make the distinction clear: in one, a company pays its staff 9 baht a kilometre for a car and 5 for a motorcycle, and the ruling discusses whether the payment is taxable income, deducting the 4 baht official rate in its worked example. The company's rates are examples of what one employer pays, not national figures.

The tax treatment of what a private employer pays depends on conditions: that the travel was a necessary expense of assigned work, that the employer approved it with the work and the period identified, and that there is evidence of the expense. A mileage log supports all of that. It does not, on its own, make a payment tax free.

So the app treats the figure as a benchmark. The scheme screen calls it the government travel reimbursement rate, the onboarding and the claim caption say that private employers set their own rate, and the PDF footer says the figures do not establish a tax exemption. If your employer pays something else, type it into the employer rate field and the comparison is shown against the benchmark, without calling the difference tax relief.

Both vehicles, one scheme

Thailand is the first scheme the app shipped with two rates, and it is why 1.2.0 gave every vehicle a type. A Thai driver with a car and a motorcycle logs both under one scheme and each trip is priced at its vehicle's rate, 4 baht or 2. The claim PDF names the vehicle on each line.

Thai, the language

The language is a separate choice from the rates, as it is for every language in the app. A Thai speaker driving in Britain reads Thai and claims HMRC rates; a British expat in Bangkok reads English and claims 4 baht. Thai dates use Thai month and weekday names with Gregorian years, which is what the claim year, the CSV and a Thai accountant expect, rather than the Buddhist Era years a phone's calendar sometimes shows.

The Thai translation was done this autumn and has been checked for structure and terminology, not yet read by a native speaker in every corner of the app. If you find a sentence that reads wrongly, tell us: it is the kind of thing that only a Thai reader can catch.

Claim figures are estimates to help you keep a record. They are not tax advice, in Thailand or anywhere else.

Sources

• คู่มือการให้บริการ การเบิกจ่ายค่าใช้จ่ายในการเดินทางไปราชการ, Secretariat of the Prime Minister, April 2020. Page 12 gives 4 baht a kilometre for a private car and 2 for a motorcycle, citing Ministry of Finance letter 0409.6/Wor 42 of 26 July 2007.
• Revenue Department ruling 0702/1831, Revenue Department of Thailand. How mileage paid by a private company is treated, with the 4 baht official rate deducted in the worked example.