Situation guide
Expat Personal Income Tax Guide in Thailand: 180-Day Rule, P.N.D.90/91 & Foreign Remittance Orders
Foreign executives, digital nomads, expatriates and retirees with overseas income.
Quick answer
Foreign nationals whose aggregate presence reaches 180 days within a calendar tax year are Thai tax residents. Thai employment income is taxed at progressive rates of 0–35%, filed on P.N.D.91 (salary only) or P.N.D.90 by 31 March, or about 8 April online. A resident's foreign income brought into Thailand is taxable under Order Paw.161/2566, except income earned before 2024 (Paw.162/2566), treaty relief, or qualifying LTR status, where highly skilled professionals may elect 17% on employment income.
The PDF button opens a print-ready sheet — choose “Save as PDF” in the browser dialog. It contains the key facts, the document checklist and the timeline.
Detailed guidance
1. Count days before computing tax
Tax residence under section 41 is based on aggregate days physically present in Thailand during the calendar year, not visa type or home ownership. Reaching 180 days makes the person resident for that whole year. Frequent travellers should keep a day count from passport stamps and travel records, because crossing the threshold unnoticed brings foreign income remitted that year into Thai tax.
Non-residents remain taxable on income from work performed in Thailand wherever it is paid. The day count therefore mainly governs foreign-source income; it does not exempt salary for Thai work. An executive paid by an overseas parent for duties performed in Thailand still has Thai-source assessable income.
2. Foreign income under Paw.161 and Paw.162
From tax year 2024, Order Paw.161/2566 treats a resident's foreign-source income as assessable for whichever year the money enters Thailand, even if earned earlier. Paw.162/2566 excludes income arising before 1 January 2024, so the year income arose must be proved with statements, sale documents or accounts separating principal from returns. Bringing in pre-2024 savings principal is not new income when it can be evidenced separately.
Gains on foreign shares or funds brought into Thailand are assessable under section 40(8) or (4). Where the source country already taxed them, a DTA may give a credit capped at the Thai tax on that income. Certain LTR categories have a conditional exemption for remitted foreign income under Royal Decree 743, so confirm the exact LTR category before relying on it.
3. Deductions, allowances and which form
Employment income takes a 50% expense deduction, capped at THB 100,000 for combined section 40(1) and (2) income, not 50% of total salary. Personal allowance, social security, qualifying life and health insurance premiums and provident fund contributions follow. Premiums paid to foreign insurers not licensed in Thailand are often not deductible. Salary-only filers use P.N.D.91; those with other income, including remitted foreign income, use P.N.D.90.
The Thai employer withholds monthly and issues a 50 Tawi withholding certificate at year end. The employee reconciles full-year income, including bonuses, taxable benefits such as employer-paid housing, and any tax borne by the employer, which is itself additional income, before filing online through the Revenue Department system.
4. Leaving Thailand and tax certificates
Anyone leaving mid-year should complete filings before departure or appoint a representative, and collect all withholding certificates. The Revenue Department still operates a tax clearance procedure for certain foreigners, such as those with business income or income not fully withheld, so check with the local revenue office before departure, bringing the passport, work permit and 50 Tawi certificates.
A team with an extensive track record in expatriate personal tax can build the day count, separate principal from income and prepare the return. Contact staff for a quotation with income sources and countries involved. This guide is source-based editorial guidance, not an individual tax assessment.
Key facts
| Residency threshold | 180 days or more in the tax year, aggregated |
|---|---|
| Progressive rates | 0% to 35% of net income |
| Annual deadline | 31 March (paper) / about 8 April (online under the extension notice) |
| Employment expense deduction | 50% capped at THB 100,000 |
| LTR highly skilled | Optional 17% on qualifying employment income only |
Practical summary
If you only read one block, start with these five lines and return to the detail afterwards.
- 1.Monthly — Thai employer withholds salary tax.
- 2.January-March — Compute annual tax and gather documents.
- 3.Before the statutory cutoff — File online and pay any balance.
- 4.Form 50 Tawi withholding certificates
- 5.Passport with immigration stamps
Document checklist
Form 50 Tawi withholding certificates
Credits tax already withheld by employers.
Passport with immigration stamps
Proves days present in Thailand.
Foreign inward remittance records (SWIFT/credit advice)
Shows the year and source of funds brought in.
Social security and health insurance proofs
Supports the allowances claimed.
Timeline
Monthly
Thai employer withholds salary tax.
January-March
Compute annual tax and gather documents.
Before the statutory cutoff
File online and pay any balance.
Common mistakes
- Not tracking days in Thailand and becoming resident unexpectedly.
- Ignoring tax on foreign capital gains brought into Thailand.
- Misreading the 50% employment deduction, which is capped at THB 100,000.
Repeat questions
Under Paw.162/2566, income arising before 1 January 2024 is not included when remitted in later years, provided the year it arose is evidenced, for example by earlier account statements.
Contact the responsible local revenue office with your passport, work permit, 50 Tawi certificates and filing evidence; officers check for outstanding tax. Confirm the current document list first, as the procedure applies only in certain cases.
Verifiable sources
These original sources address the issues described under each reference; they do not certify every statement or a service outcome. Check amendments and the conditions applicable to the entity's actual circumstances.
1. Guidance
Revenue Department: PND.90 instructions for tax year 2025, who must fileThe Revenue Department
For income beyond Section 40(1) alone: single filers above THB 60,000, married filers combined above THB 120,000.
2. Guidance
Revenue Department: PND.91 instructions for tax year 2020, who must fileThe Revenue Department
Salary-only Section 40(1) income: single filers above THB 120,000, married filers combined above THB 220,000 (tax-year 2020 edition; check the current year's rule).
3. Guidance
Revenue Department: personal income tax filing deadlinesThe Revenue Department
PND.90 and 91 are filed January to March of the following year, online if preferred; with no tax due the system confirms receipt with a reference number.
4. Notification
Revenue Department Order Por.161/2566: tax under section 41, paragraph 2The Revenue Department
Foreign-source income remitted from 1 January 2024, with the carve-out for income earned before that date under the amending order.
5. Notification
RD Order Por.162/2566: income arising before 2024The Revenue Department
Carves out pre-2024 income, not later returns simply because an account was opened earlier.
6. Guidance
Revenue Department Q&A on Orders Por.161 and Por.162 (foreign-source income)The Revenue Department
Explains the two conditions, 180 days or more in Thailand and remittance in that or a later year, with an example.
7. Act
Royal Decree No.743: LTR income-tax treatmentThe Revenue Department
Sections 3–4 address eligible employment income at 17%; section 5 addresses specified overseas income for three categories. BOI-hosted translation.
8. Guidance
Revenue Department: personal income tax (residents)The Revenue Department
Defines residence as 180 days in a calendar tax year and the tax on foreign-source income brought into Thailand.
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