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calcthai.com · Thailand Corporate Income Tax Calculator
Money & tax
Thailand Corporate Income Tax Calculator
Calculate Thai corporate income tax on net profit, check whether your company qualifies for the reduced SME rates, and see why the 10% figure still quoted online expired after the 2016 accounting period.
Corporate income tax rates in force for the current accounting period
| Net profit | Qualifying SME | General company |
|---|---|---|
| Up to 300,000 baht | Exempt | 20% |
| Over 300,000 up to 3,000,000 baht | 15% | 20% |
| Over 3,000,000 baht | 20% | 20% |
Tax comparison — qualifying SME versus general rate
| Net profit | SME | General 20% | Difference |
|---|---|---|---|
| 300,000 | 0 | 60,000 | 60,000 |
| 500,000 | 30,000 | 100,000 | 70,000 |
| 1,000,000 | 105,000 | 200,000 | 95,000 |
| 2,000,000 | 255,000 | 400,000 | 145,000 |
| 3,000,000 | 405,000 | 600,000 | 195,000 |
| 5,000,000 | 805,000 | 1,000,000 | 195,000 |
| 10,000,000 | 1,805,000 | 2,000,000 | 195,000 |
Ask about this page
The AI assistant answers only questions about the calculator on this page.
Companies and juristic partnerships in Thailand pay corporate income tax on net profit, normally at 20%. Smaller companies that meet the conditions get reduced, banded rates instead, which cut the bill substantially at lower profit levels. This page works out both at once and tells you whether your company qualifies.
The thing to watch is out-of-date figures. Many accounting blogs still state 10% for the middle band. That was correct only for the 2015 and 2016 accounting periods. Royal Decree No. 603 (2016) changed it to 15% for accounting periods beginning on or after 1 January 2017. Anyone calculating with 10% understates the tax by a third.
How it works
Qualifying for the reduced rates requires both conditions: paid-up capital on the last day of the accounting period of no more than 5 million baht, and sales and service revenue for the period of no more than 30 million baht. Note the wording — "sales and service revenue", not total revenue — and that the conditions must be met continuously from the accounting period beginning on or after 1 January 2012.
The reduced SME rates are banded and cumulative, like personal income tax: the first 300,000 baht of net profit is exempt, the portion above 300,000 up to 3,000,000 is taxed at 15%, and anything above 3,000,000 at 20%.
The general rate is 20% on the whole net profit, with no exempt portion and no bands. It sits in the rate schedule attached to the Revenue Code, amended to 20% by Act No. 42 (2016), so it is no longer a temporary reduction needing renewal.
Taxable net profit is usually not accounting profit, because the Revenue Code disallows certain expenses and requires other adjustments. Enter the adjusted figure.
Filing. The annual PND 50 is due within 150 days of the end of the accounting period; the half-year PND 51 within 2 months of the end of the first six months. A common trap: under-estimating net profit on PND 51 by more than 25% without reasonable cause brings a 20% surcharge on the shortfall.
Frequently asked questions
Is the SME rate 10% or 15%?
It is 15% for accounting periods beginning on or after 1 January 2017. The 10% rate applied only to the 2015 and 2016 periods. Royal Decree No. 603 (2016) sets them out in separate sub-paragraphs: the 10% one is tied to those specific years, while the 15% and 20% bands carry no end date.
Registered capital or paid-up capital — which counts?
Paid-up capital on the last day of the accounting period, not registered capital. A company registered at 10 million but with only 3 million actually paid up is assessed on the 3 million, which is within the 5 million limit.
Does the 30 million include interest and other income?
The law says revenue from the sale of goods and the provision of services, which is narrower than total revenue. Other categories such as interest received or gains on disposing of assets are not within that wording. For complex cases, take advice from your accountant or ask the Revenue Department directly.
Revenue exceeded 30 million this year but will drop next year — do the reduced rates come back?
No. Section 8 of Royal Decree No. 530 requires the conditions to be met continuously from the accounting period beginning on or after 1 January 2012. Once breached in any period, the company does not re-qualify.
Does a loss-making company still have to file?
Yes. The filing obligation does not depend on whether tax is payable. A company with a loss or no income at all must still file PND 50 on time. Net losses can be carried forward against profits for up to five subsequent accounting periods, subject to the rules.
What if the PND 51 estimate is too low?
If the estimated net profit falls short of the actual figure by more than 25% without reasonable cause, a surcharge of 20% of the underpaid tax applies. Businesses whose profits accelerate in the second half often get caught by this, so estimate carefully.
Sources
- Royal Decree No. 603 (2016) — the SME rates in force
- Revenue Code Amendment Act No. 42 (2016) — the 20% general rate
- Royal Decree No. 530 (2011) — the 5 million and 30 million conditions
- Revenue Department — PND 51 filing instructions, 2026 periods
Rates last verified 6 Sep 2026