Thailand Income Tax. Thailand income taxation system is governed primarily by the Revenue Code B.E. 2481 (1938), and is administered by the Revenue Department under the Ministry of Finance. The tax regime applies both to resident and non-resident individuals, as well as juristic persons (companies) operating in Thailand or deriving income from Thai sources.
Taxation is source-based for non-residents and global income–based for residents (under limited remittance rules). The system is composed of personal income tax (PIT), corporate income tax (CIT), and a number of withholding tax (WHT) mechanisms. This article analyzes the legal structure, taxpayer classifications, filing requirements, and key interpretations relevant under Thai tax law.
II. Legal Foundation and Administrative Structure
A. Governing Laws and Regulations
-
Revenue Code B.E. 2481 – primary tax legislation, covering PIT, CIT, and VAT
-
Royal Decrees and Ministerial Regulations – frequently used to adjust rates and rules
-
Double Tax Agreements (DTAs) – Thailand is party to over 60 treaties
-
Transfer Pricing Law (2019) – governs related-party transactions
B. Tax Authority
The Thai Revenue Department is responsible for:
-
Collection of income and indirect taxes
-
Issuance of rulings and interpretations
-
Audits and tax assessments
-
Enforcement of penalties for non-compliance
III. Personal Income Tax (PIT)
A. Taxpayer Classification
-
Resident Taxpayers
-
Defined as individuals residing in Thailand for 180 days or more in a tax year
-
Subject to tax on worldwide income, but only if remitted to Thailand within the same year
-
-
Non-Resident Taxpayers
-
Taxed only on income derived from or in Thailand
-
No remittance rule applies—immediate liability
-
B. Taxable Income Categories (Section 40 RC)
Thailand categorizes income into eight types:
-
Employment income (salary, wages, bonuses)
-
Service fees and contract work
-
Royalties
-
Dividends and interest
-
Rental income
-
Professional income (law, medicine, engineering)
-
Business income (sole proprietorship)
-
Capital gains (unless exempted, e.g., on Thai stock exchange)
Each category has specific deduction rules, and tax is imposed after allowances and exemptions.
C. PIT Rates (Progressive Scale)
| Taxable Income (THB) | Tax Rate |
|---|---|
| 0 – 150,000 | Exempt |
| 150,001 – 300,000 | 5% |
| 300,001 – 500,000 | 10% |
| 500,001 – 750,000 | 15% |
| 750,001 – 1,000,000 | 20% |
| 1,000,001 – 2,000,000 | 25% |
| 2,000,001 – 5,000,000 | 30% |
| Over 5,000,000 | 35% |
D. Deductions and Allowances
-
Standard Deduction: 50% of employment income (capped at THB 100,000)
-
Personal allowance: THB 60,000 per taxpayer
-
Dependent allowance: THB 30,000–60,000 per child or parent
-
Insurance premiums, pension contributions, and charitable donations: subject to thresholds
IV. Corporate Income Tax (CIT)
A. Taxable Entities
Under Section 66 RC, the following are liable:
-
Companies and partnerships incorporated in Thailand
-
Foreign companies doing business in Thailand
-
Foreign companies receiving income from Thailand (via WHT)
B. CIT Rates
| Entity Type | Rate |
|---|---|
| Standard companies | 20% |
| SMEs (profits < THB 3M; capital < THB 5M) | 15% on first THB 300,000; 20% thereafter |
| BOI-promoted entities | Exempt or reduced rates (by promotion) |
| Foreign company (on Thai income) | 15%–20% via WHT or deemed profit basis |
Note: Foreign companies not operating in Thailand but receiving income may be taxed on a deemed profit basis (Section 70 RC), generally presumed to be 50% of gross income.
V. Withholding Tax (WHT)
Thailand uses a robust WHT regime for both residents and non-residents.
| Income Type | Resident WHT Rate | Non-Resident WHT Rate |
|---|---|---|
| Dividends | 10% | 10% |
| Interest | 1% | 15% |
| Royalties | 3% | 15% |
| Service fees | 3% | 5%–15% |
| Rents | 5% | 15% |
WHT may be creditable against final tax or final tax depending on the nature of the income and whether the recipient is a Thai resident.
Double tax treaties may reduce or eliminate WHT obligations; however, DTA relief must be claimed via form submission (Form PND.54) with certificate of residence.
VI. Special Regimes and Exemptions
A. Board of Investment (BOI) Promotion
BOI-promoted projects may receive:
-
CIT exemptions (up to 13 years)
-
Exemption from import duties
-
Permission to own land and employ foreigners
B. Long-Term Resident Visa (LTR) Regime
Qualifying foreigners under the LTR scheme may enjoy:
-
Flat 17% personal income tax rate (for professionals in targeted industries)
-
Possible exemption on foreign-source income if not remitted in the same year
C. Offshore Remittance Rule for Residents
Thai residents are liable for tax on offshore income only if remitted into Thailand in the same calendar year. As per Revenue Department Order No. Por.161/2566 (2023), from 2024 onward:
“All offshore-sourced income is taxable in the year it is brought into Thailand, regardless of when it was earned.”
This closes a prior deferral loophole.
VII. Filing, Assessment, and Penalties
A. Personal Income Tax
-
Tax year: Calendar year
-
Filing deadline: March 31 (manual) / April 8 (electronic)
-
Installment payment allowed for large sums (Section 63 RC)
B. Corporate Income Tax
-
Accounting period: Generally follows calendar or fiscal year
-
Interim return (PND 51) due after 6 months
-
Final return (PND 50) due 150 days after year-end
C. Penalties and Surcharges
| Offense | Penalty |
|---|---|
| Late filing | THB 2,000–5,000 fine |
| Late payment | 1.5% monthly surcharge (up to 100%) |
| Failure to withhold tax | Up to twice the tax due + 1.5% monthly surcharge |
| False declarations | Criminal liability (Section 37 RC) |
Voluntary disclosure may mitigate penalties.
VIII. Dispute Resolution and Tax Appeals
A. Tax Assessment Review
Taxpayers may dispute assessments within 30 days by:
-
Filing with the Appeals Committee under Section 71 RC
-
Submitting supporting documents and evidence
B. Court Proceedings
If unsatisfied, the taxpayer may appeal to:
-
Tax Court (established under the Act on Establishment of Tax Court B.E. 2528)
-
Further appeals may be lodged to the Supreme Court (Dika Court) in limited cases
IX. Conclusion
Thailand’s income tax regime is structured, statute-driven, and enforced through robust procedural mechanisms. Both individuals and entities must navigate complex rules related to source of income, residence status, exemptions, and filing obligations.
Given recent reforms—especially in offshore remittance taxation and international information exchange (AEOI/CRS)—residents, expatriates, and multinational entities should ensure comprehensive compliance and transaction-level planning to mitigate risk and avoid disputes.
