Thailand Income Tax

Thailand Income Tax. Thailand taxes individuals and juristic persons on a calendar-year basis. Tax residency for individuals is determined by physical presence: a person who resides in Thailand for an aggregate 180 days or more in a tax year is a Thai tax resident and is subject to Thai tax rules for that year. Non-residents are taxed only on Thai-source income.

A major recent change affects foreign-sourced income: under Revenue Department guidance issued in late 2023 (effective 1 January 2024), foreign-sourced income brought into Thailand by a Thai tax resident can be taxable. The Revenue Department has issued further clarifications and draft measures proposing reliefs (for example transitional/exemption windows), so the treatment of remitted overseas income is now an active policy area — residents and returning expatriates must watch the Revenue Department’s updates closely.

1. Personal Income Tax (PIT) — rates & who pays

Thailand’s PIT system is progressive. For individuals the net taxable income bands and rates (typical current structure) are:

• 0 – 150,000 THB: 0%

• 150,001 – 300,000 THB: 5%

• 300,001 – 500,000 THB: 10%

• 500,001 – 750,000 THB: 15%

• 750,001 – 1,000,000 THB: 20%

• 1,000,001 – 2,000,000 THB: 25%

• 2,000,001 – 5,000,000 THB: 30%

• 5,000,000 THB: 35%.

Taxable “net” income is computed after allowable deductions and allowances described below.

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2. Key personal deductions & allowances

Thailand offers a range of standard allowances and specific deductions that materially affect tax liability:

• Personal allowance: 60,000 THB for the taxpayer (plus 60,000 THB for a non-earning spouse).

• Child allowance: 30,000 THB per child (special additional rules for children born after 2018).

• Parental care: 30,000 THB per dependent parent (with income limits for the parent).

• Standard employment expense deduction: often 50% of employment income up to a ceiling (typically 100,000 THB).

• Life/health insurance, pension and retirement savings: a variety of caps apply (e.g., life insurance deductions up to certain limits, provident/retirement fund deductions subject to ceilings).

• Mortgage interest and some special investments (e.g., approved ESG or pension products) may qualify for deductions or extra incentives under temporary measures.

Always confirm current ceilings and new temporary incentives (some measures introduced 2024–2025 are time-limited).

3. Corporate Income Tax (CIT) & special rules

Thailand’s headline corporate tax picture is:

• Small/SME progressive bands and thresholds apply for very small profits, but for many companies the normal CIT rate has been 20%; recent policy changes and incentives mean effective rates can be lower for eligible firms. Some guidance for 2024–25 shows reduced rates for small profits (e.g., 0% on the first ~THB300k, 15% on the next band, 20% thereafter), and Thailand implemented OECD-aligned global minimum top-up rules for large multinationals (15% minimum) from 2025. Check the Revenue Department or major tax firms for the exact bands applicable to your fiscal year.

The Board of Investment (BOI) and other incentive programs can give long tax holidays or exemptions for promoted activities — but those are conditional and require strict compliance.

4. Withholding taxes (WHT) and common rates

Thailand operates a widespread withholding tax regime on payments to residents and non-residents (employment, services, royalties, dividends, interest, rents). Common statutory rates include (subject to treaty relief and temporary measures):

• Employment remuneration: withheld on a sliding scale (employer withholds according to employee tables).

• Service/professional fees (to resident persons): generally 3% statutory WHT on fee payments; for non-resident service providers a final WHT is commonly 15% (rates depend on type of payment and DTA).

• Dividends: typically 10% WHT (resident dividend credit rules apply).

• Interest & royalties: often 10–15% for non-residents (treaty relief can reduce this).

From 2023 to 31 December 2025 some WHT rates have been temporarily reduced if taxes are remitted via the e-withholding tax system — check the Revenue Department and your tax adviser for the exact temporary rates that may apply to specific payments.

5. Filing & payment timing — what to watch

Key calendar items:

• Personal income tax (annual): individuals file annual returns (Forms PND90/91). Paper and e-filing deadlines vary by year; Revenue Department guidance and tax calendars (published annually) set the exact dates (generally return and payment deadlines fall in March/April depending on e-filing rules). Employers must withhold monthly and submit withholding forms on fixed schedules.

• Corporate tax: corporate income tax returns and monthly/quarterly instalments (advance payments and final return) follow statutory schedules; late payments and under-payments trigger interest and penalties.

Because deadlines, forms and e-filing windows are updated annually, always confirm the current tax calendar published by the Revenue Department or major accounting firms.

6. Enforcement, audits and cross-border traps

Thai tax authorities have sharpened focus on (a) remitted foreign income, (b) proper reporting of withholding and (c) transfer pricing for related-party transactions. Audits can result in reassessments, penalties and interest; in serious cases criminal tax investigations are possible. Keep complete source documentation for foreign income remittances, agent confirmations for withholding, and contemporaneous transfer-pricing documentation for inter-company transactions.

7. Practical checklist (what to do now)

1. Confirm your residency status (180-day test).

2. If you are a resident, identify any foreign income and track when it is remitted into Thailand; consult a tax adviser about the current remit-and-tax rules and any transitional relief.

3. Gather allowances/deductions documents (insurance, pension, mortgage, dependent evidence).

4. Ensure payroll withholding and WHT compliance (rates, remittance channels, e-withholding).

5. If you run a company, review whether BOI or other incentives apply and the impact of the global minimum tax if you are part of a large multinational.

Conclusion

Thailand’s income tax system mixes standard progressive PIT, detailed allowances, a regime of withholding taxes and targeted corporate incentives. Recent policy changes — most notably the treatment of foreign-sourced income remitted into Thailand and the implementation of the global minimum tax for large multinationals — mean taxpayers (individuals and companies) should get up-to-date advice before remitting funds or structuring cross-border arrangements. For any material or cross-border case, consult a reputable Thai tax adviser or the Revenue Department directly (forms and annual guidance are published on the RD website).