Thai tax residency and foreign income.
The 180-day test is only the first step. For foreign income, the critical questions are when it arose, whether you were resident in Thailand in that earning year, whether it was remitted, and whether an exemption or double-tax agreement changes the result.
Key checks
- First establish
- Aggregate days in Thailand for the calendar year and residence in the year the income arose.
- Then classify
- Income source, earning year, remittance timing and the evidence connecting each transfer to that income.
- Before concluding
- Check exemptions, the applicable DTA, foreign tax actually paid, credit limits and current filing guidance.
A visa does not determine domestic tax residence. Some LTR categories have specific relief, but the category and income type must match the law.
Read this before anything else
This page is general information, not tax advice
Thai tax treatment depends on the source and type of income, the year it arose, your residence status in that year, the year and amount remitted, exemptions, and the relevant double-tax agreement. This page is general information, not individual tax, legal or financial advice. Keep evidence for earning dates, source, foreign tax paid and transfers, and obtain qualified Thai and home-country advice before a material remittance or filing decision.
Tax residency starts at 180 days
Under Section 41, a person staying in Thailand for an aggregate of 180 days or more in a calendar year is treated as resident for that tax year. The days need not be consecutive. Residence is tested year by year and is separate from immigration status: a visa controls permission to stay, not the tax calculation.
Thai-source income is a separate branch. Revenue Department guidance states that income from work, business or property in Thailand can be taxable whether it is paid inside or outside Thailand. The foreign-income sequence below must not be used to decide the treatment of Thai-source work.
The earning year comes before the remittance year
Revenue Department guidance describes foreign-source income as subject to Thai personal income tax when both core conditions are met: it arose from 1 January 2024 onward while the individual was resident in Thailand in that earning year, and some or all of that income was later remitted to Thailand. The assessable amount is included in the return for the year of remittance.
That means residence in the remittance year alone is not the complete test. The official examples also state that income earned before 1 January 2024, or income earned while the individual was not resident in Thailand, is not brought into charge merely because it is remitted later. The source and earning year must be evidenced rather than inferred from the transfer date.
- Identify the sourceThai-source and foreign-source income follow different Section 41 branches.
- Record the earning yearIncome earned before 1 January 2024 is treated differently under current Revenue Department guidance.
- Test residence in that earning yearCount aggregate days in Thailand for the calendar year in which the foreign income arose.
- Trace the remittanceRecord how much of that income entered Thailand and in which tax year.
- Check reliefReview domestic exemptions, the applicable DTA and documented foreign tax paid before calculating a filing position.
The LTR visa and Royal Decree 743
Section 5 of Royal Decree No. 743 provides foreign-income relief for three named LTR categories: Wealthy Global Citizen, Wealthy Pensioner and Work-from-Thailand Professional. It does not create one blanket exemption for every LTR holder or every receipt.
The Highly Skilled Professional category has a separate tax treatment described by BOI, including a 17% personal-income-tax regime for qualifying employment income. Do not transfer the Section 5 foreign-income statement to that category. Confirm the category, income type and current conditions before relying on any LTR tax benefit; the visa comparison is a route overview, not a tax ruling.
Who should file, and how treaties help
Filing. Whether a return is required depends on the assessable-income categories and filing thresholds that apply to the facts. Filing and owing tax are not the same. Use the Revenue Department's current filing calendar and forms for the relevant tax year rather than assuming one deadline or form covers every case.
Double-tax agreements. The Revenue Department's 2025 foreign-tax-credit manual says Thailand has DTAs with 61 jurisdictions and that treaty residence, income type, taxing rights and credit limits must be checked country by country. A credit requires evidence of eligible foreign income tax actually paid and cannot exceed the Thai tax attributable to that income. Keep tax returns, withholding certificates, official receipts and transfer evidence.
// Build the evidence in sequence
Start with presence; finish with the applicable rule.
Build the calendar-year record, preserve the earning-year and remittance evidence, and verify the current rule against the Revenue Department and qualified advice before taking a filing position.
What to prepare before asking for advice
Build a year-by-year record. For each income stream, retain the source country, income type, date and year earned, days in Thailand in that earning year, amount remitted, transfer date and foreign tax evidence.
Separate income from capital. A bank transfer label does not prove whether funds represent salary, pension, dividends, asset-sale proceeds, savings or another category. Ask an adviser what evidence establishes the character and earning year.
Check the actual treaty. Do not assume a DTA makes all foreign income tax-free. Treaty residence, the income article, source-country taxing rights and the relief method can differ.
Next steps. Use the day counter for one calendar year, compare immigration routes in the visa guide, and verify the final position with the Revenue Department or a qualified adviser.
Thai-tax questions, answered
When do I become a Thai tax resident?
Under the domestic Section 41 test, when your presence in Thailand totals 180 days or more in a calendar year. The test is annual and separate from your visa.
Does residence in the remittance year make old foreign income taxable?
Not by itself. Current Revenue Department guidance first tests whether the income arose from 1 January 2024 onward while you were resident in Thailand in that earning year, then whether it was remitted. Income earned before 2024 and income earned while non-resident are treated differently.
Does every LTR category have the same foreign-income exemption?
No. Section 5 of Royal Decree No. 743 names Wealthy Global Citizen, Wealthy Pensioner and Work-from-Thailand Professional. Highly Skilled Professional has separate treatment. Category, income type and conditions must be checked.
Does a DTA guarantee that I owe no Thai tax?
No. The applicable treaty, treaty residence, income article, foreign tax actually paid and credit limit all matter. The Revenue Department recommends retaining official tax-payment and remittance evidence.
Primary-source register
Read the tax sequence at its source.
Official sources accessed 23 August 2026. Later Revenue Department orders, filing calendars or treaty guidance may change the procedure.
- Revenue Department · Section 41 explainerThai-source income and the earning-year, residence and remittance conditions for foreign-source income.Open PDF ↗
- Revenue Department · foreign tax credit manualNovember 2025 decision sequence, DTA checks, credit limits and supporting evidence.Open PDF ↗
- Revenue Code · Sections 38–64English-language statutory text including residence and assessable-income provisions.Open source ↗
- Revenue Department · DTA directoryCountry agreements must be checked by jurisdiction and income type.Open directory ↗
- Royal Decree No. 743Category-specific LTR exemptions; Section 5 names three categories.Open PDF ↗