Thailand income tax regime is administered under the Revenue Code B.E. 2481 (1938) and enforced by the Revenue Department under the Ministry of Finance. The system is structured around global taxation for residents and source-based taxation for non-residents, with distinct provisions for individuals, companies, partnerships, and international entities.
Recent changes, including the implementation of the remittance rule reform in 2024, the evolving interpretation of tax residency, and integration with global anti-tax evasion frameworks (e.g., CRS and BEPS), have made Thai income taxation an increasingly nuanced and compliance-driven area.
This article offers an in-depth analysis of Thailand’s income tax system, focusing on legal definitions, residency determination, types of taxable income, filing requirements, international tax implications, and administrative procedures.
An individual is considered a Thai tax resident if:
A non-resident is anyone present in Thailand for less than 180 days in the same year.
⚖️ Tax liability depends not just on source, but also on timing of remittance for foreign income.
The Revenue Code classifies income into eight categories, each with specific rules:
| Section 40 Type | Description |
|---|---|
| 40(1) | Employment income (salaries, wages, bonuses) |
| 40(2) | Hire of work (independent contracts) |
| 40(3) | Royalties and intellectual property |
| 40(4) | Dividends, interest, capital returns |
| 40(5) | Rental of property (land, buildings, vehicles) |
| 40(6) | Professional services (law, engineering, etc.) |
| 40(7) | Business, commerce, agriculture, transportation |
| 40(8) | Other income not falling into the above categories |
Each category is taxed differently, with some allowing deductions or standard expense rates.
| Net Taxable Income (THB/year) | 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% |
Taxable income = Total income minus deductions, allowances, and exemptions
As of January 1, 2024, Thai tax residents are subject to tax on foreign-source income if remitted into Thailand in the same calendar year it is earned.
This reform replaced the old rule (tax only when remitted, regardless of when earned), effectively limiting deferral strategies.
Thailand operates a withholding tax system in parallel with personal income tax:
| Income Type | Withholding Rate |
|---|---|
| Salaries (resident) | 0–35% (sliding scale) |
| Dividends | 10% |
| Interest | 15% |
| Royalties | 15% (with treaty relief) |
| Rent | 5% |
| Professional fees | 3–5% |
Thailand has over 60 DTAs, which govern:
| Offense | Penalty |
|---|---|
| Late filing | Fine up to THB 2,000 |
| Failure to file | Surcharge of 1.5% per month (up to full tax) |
| Understatement of tax | 100–200% surcharge |
| Tax evasion (fraud) | Criminal prosecution (imprisonment + fine) |
Thailand’s income tax system is legally structured, economically significant, and increasingly robust due to international transparency commitments and domestic enforcement reforms. While the framework remains favorable to some types of foreign income and investment, residents—especially foreign nationals—must now pay close attention to remittance timing, source definitions, and cross-border compliance obligations.
As Thai tax law evolves alongside global standards, individual and corporate taxpayers alike must treat income tax not merely as an administrative formality, but as a strategic and legal obligation with wide-ranging consequences.