DriveHubCountry guide · Thailand
A Thai sole trader cannot claim 4 baht a kilometre — the figure needs a payer
The short answer
You cannot. The 4 baht per kilometre for a private car is real, but it is a ceiling for travel money that an employer or other income-payer pays you. A sole trader filing under ม.40(8) has no per-kilometre figure anywhere in the Revenue Code or its decrees. A ม.40(8) sole trader takes either the flat percentage under Royal Decree No. 11 s. 8, or their actual costs.
Where the 4 baht comes from
The Ministry of Finance letter กค 0409.6/ว 42 (26 July 2007) sets what the Government pays its own officials: (๑) รถยนต์ส่วนบุคคล — กิโลเมตรละ ๔ บาท; (๒) รถจักรยานยนต์ส่วนบุคคล — กิโลเมตรละ ๒ บาท (private car, 4 baht per km; private motorcycle, 2 baht per km). The 2 baht is the motorcycle figure; neither is a sole trader's rate.
Revenue Code s. 42(2) exempts transport expenses at the rates prescribed by the Government for its own officials. The Revenue Department ruling กค 0702/1831 (2 March 2018) reads those rates across to the private sector. A flat vehicle allowance is exempt where it does not exceed "อัตราค่าสูงสุดที่ทางราชการกำหนดจ่ายให้แก่ข้าราชการ" — the maximum rate the Government pays its officials.
Why it needs a payer
Two texts close the door, and both start from a payer.
- Ruling กค 0702/1831 applies to sums paid "ให้แก่พนักงานของบริษัทฯ" (to the company's employees), and the receipt is "เงินได้พึงประเมินตามมาตรา 40 (1)" — employment income. A ม.40(8) trading business is not that category.
- The Director-General's construction of s. 42(1), ป.59/2538 ข้อ 2, says the travel must have evidence of approval to travel for work outside the office from a นายจ้างหรือผู้จ่ายเงินได้ — an employer or income-payer.
The dividing line is whether somebody pays you travel money. A trader on their own account has nobody to pay the allowance and nobody to sign the approval.
Employees reimbursed by an employer are in a different position, and for them the distance is the short and direct Highways route that can be travelled conveniently and safely, not the road you drove — see Thailand's claimable distance.
Why you cannot set the figure yourself
Paying yourself 4 baht a kilometre does not work around this. ม.65 ตรี (9) disallows "รายจ่ายซึ่งกำหนดขึ้นเองโดยไม่มีการจ่ายจริง" — an expense the taxpayer fixes for themselves, with no actual payment behind it.
Royal Decree No. 11 ss. 8 and 8 ทวิ bring ม.65 ตรี into both sole-trader routes. A self-assigned 4 baht multiplied by your kilometres is exactly an expense of that kind.
What you can use instead
Two routes remain for a sole trader:
- The flat percentage under Royal Decree No. 11 s. 8.
- Actual costs. You deduct what you really paid and can show.
The flat percentage is the one Royal Decree No. 11 s. 8 sets. Which route suits you depends on your income and costs; ask your accountant. Neither route multiplies kilometres by a rate.
A ruling about a company that tried it
Ruling กค 0702/88 is the closest case. A company built a per-kilometre model with odometer logs and receipts. The Revenue Department disallowed the excess over actual spend under ม.65 ตรี (3), and the ruling is still reproduced in the Department's June 2024 audit manual.
A neat log did not rescue a rate that was not an actual cost. Related ruling กค 0702/1121 holds that a formula-derived monthly vehicle allowance is "ไม่อยู่ในความหมายของมาตรา 42(1)" — not within the meaning of s. 42(1).
Why a dated log still matters
On the actual-cost route you deduct what was really paid. A dated record of each drive, with business and private kilometres kept apart, is practical evidence of how much of the driving was for the business. No provision prescribes a mileage log as such.
The Revenue Code also obliges an individual to make a daily record and to produce documents on a summons. The summons limit in s. 19 is two years from filing, which the Director-General may extend to five on suspicion of evasion (no limit under s. 23 if you never filed); see how long to keep mileage records in Thailand. An assessment after an ignored summons may not be appealed (s. 21).
How DriveHub helps a Thai sole trader
DriveHub gives a sole trader no per-kilometre rate in Thailand. What it does is the record. With location access set to Always, DriveHub records every drive in the background — and if it ever misses one, it tells you. It files most trips as Business or Personal by your places, past routes and working hours, and asks you about the rest. That gives you dated business and private kilometres to bring to an accountant.
The country page is at /help/th, and the set-up steps are in setting up automatic tracking. DriveHub is on the App Store.
More for Thailand
This page states what the Revenue Code, the Ministry of Finance letter, the Revenue Department rulings, the Director-General's order ป.59/2538 and Royal Decree No. 11 say, and cites them so you can check. It is not tax advice. It can't account for your circumstances — and which route a sole trader takes is a question for your accountant.
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The full rule for Thailand, with the instruments it comes from: mileage log requirements in Thailand.