Thailand Corporate Tax Guide

Thailand's Corporate Income Tax (CIT) rate is a standard 20% of net profits for most companies. Small and medium enterprises (SMEs) benefit from a progressive sliding scale of 0–15% on the first tranches of taxable profit. BOI-promoted industries can receive CIT exemptions (0%) or 50% reductions for 3–8 years. Half-year CIT filing is required. Dividends from SET-listed companies are exempt from withholding tax. All amounts in THB.

Thailand's Corporate Income Tax (CIT / ภาษีเงินได้นิติบุคคล) is governed by the Revenue Code and administered by the Revenue Department (กรมสรรพากร). The standard 20% rate applies to both Thai-incorporated and foreign companies operating in Thailand. For related guidance, see our Personal Tax Guide →, VAT Guide →, and Investment Income Guide →.

Corporate Income Tax Rate — 20%

Standard rate: A flat 20% on net taxable profits for all incorporated companies, including both Thai and foreign companies operating in Thailand.
Taxable income: Worldwide income for Thai-incorporated companies; Thai-sourced income only for foreign companies (unless a permanent establishment exists in Thailand, in which case worldwide income attributable to the PE is taxable).
Accounting period: Generally the calendar year or a 12-month period approved by the Revenue Department. Most companies use the calendar year (January–December).

SME Tax Rates — 0–15% Sliding Scale

Small and medium enterprises (SMEs) with paid-up capital not exceeding THB 5 million and annual revenue not exceeding THB 30 million may qualify for preferential rates on the first tranches of taxable profit:
0% — on net profit up to THB 300,000 (exempt)
15% — on net profit from THB 300,001 to THB 3,000,000
20% — on net profit exceeding THB 3,000,000 (standard rate)
SMEs that are newly registered juristic partnerships may enjoy additional reductions in the first 3–5 years of operation.
These reduced rates are subject to annual renewal by Royal Decree and may vary slightly from year to year.

BOI Promoted Industries — 0–10% Incentives

The Board of Investment (BOI / สำนักงานคณะกรรมการส่งเสริมการลงทุน) offers tax incentives for industries deemed strategic or beneficial to Thailand's economic development.
CIT exemption (0%): BOI-promoted projects may receive a full exemption from CIT for 3–8 years (depending on the industry category and project merits). The exemption applies to net profits from the promoted activity.
CIT reduction (50%): After the exemption period, a 50% reduction of the standard 20% rate (i.e., effective 10%) for an additional 3–5 years.
Priority industries: Targeted sectors include advanced manufacturing, electric vehicles (EV), renewable energy, digital/software, biotechnology, medical devices, and smart electronics.
Non-tax incentives: BOI-promoted companies also receive land ownership rights, work permit facilitation, and import duty exemptions on machinery and raw materials.
IEAT: Companies in Industrial Estate Authority of Thailand (IEAT) zones may receive additional incentives, including reduced tax rates on remitted profits.

Half-Year CIT Filing and Payment

Half-year return: Companies must file a half-year corporate income tax return within 2 months of the end of the first 6-month period of the accounting year (by August for calendar-year companies).
Payment: The half-year payment is estimated at 50% of the estimated annual CIT. If actual results differ, an adjustment is made with the annual return. No penalty applies if the half-year estimate is at least 50% of the actual annual tax.
Annual return: The full-year CIT return (PP.30) must be filed within 150 days of the end of the accounting period (by 30 May for calendar-year companies). Any balance due is payable with the return.
Withholding tax credits: CIT paid via withholding on revenue (e.g., 3% WHT on service income from government, 1% on subcontractor payments, 0.5–1% on certain services from companies) is creditable against the annual CIT liability.

Dividends and Withholding Tax

No WHT on dividends from listed companies: Dividends paid by companies listed on the Stock Exchange of Thailand (SET) or the Market for Alternative Investment (MAI) to other Thai-incorporated companies are exempt from withholding tax (if the recipient company holds at least 25% of shares and the payer has not claimed a deduction for the dividend).
WHT on unlisted company dividends: 10% withholding tax applies to dividends paid by unlisted companies to Thai corporate shareholders (exempt if the recipient holds 25%+ and certain conditions are met).
WHT on dividends to individuals: 10% withholding (see Investment Income Guide).
WHT on dividends to non-residents: 10% standard rate (may be reduced under an applicable Double Tax Agreement).

Loss Carryforward

Net operating losses can be carried forward for up to 5 years from the year the loss was incurred (extended to 8 years for companies that continued operations during the COVID-19 period under temporary measures).
Loss carryback is not permitted in Thailand.
Losses from a business that is not BOI-promoted cannot offset profits from a BOI-promoted business (separate accounting required).