Tax for Expats in Phuket: The 180-Day Rule, Foreign Income and Double Tax

The 180-day test

You are a Thai tax resident for a calendar year if you are in Thailand for 180 days or more in that year, counting all days and not only consecutive ones. At 179 days or fewer you are a non-resident for that year. Tax residence is separate from your visa, and having a long-stay visa does not make you a tax resident by itself, just as a short visa does not stop it.

A resident is taxed on Thai-source income and also on foreign income that is brought into Thailand. A non-resident is taxed only on Thai-source income. If you travel a lot, keep a record of your days using your passport stamps and flight bookings, because the count decides everything else.

What changed on 1 January 2024

Before 2024, many residents avoided Thai tax on overseas income by bringing it in during a later year than the one in which it was earned. The Revenue Department changed its position in Departmental Instruction Por. 161/2566, effective for income brought into Thailand from 1 January 2024. A follow-up instruction, Por. 162/2566, confirmed that income earned before 1 January 2024 is not affected.

In practice, for a tax resident, foreign income earned from 2024 onward that is brought into Thailand is assessable in the year it arrives, whenever it was earned. Income earned before 2024 and brought in later is generally not taxed, so keep proof of when savings were earned or held. Proposals to soften the remittance rule have been discussed, but sources I found in autumn 2026 say they had not been enacted, so check the current position before you rely on one.

What counts as foreign income

Employment or business income earned abroad, rental income from property abroad, pensions, interest and dividends can all be assessable when remitted by a resident. Whether a particular pension is taxed in Thailand also depends on the tax treaty between Thailand and the paying country, and some treaties give the exclusive right to tax certain government or public-service pensions to the paying country.

Money that is a gift, an inheritance or a return of your own savings is generally not income. How the money is labelled by the bank can matter, so keep records showing what each transfer is.

Double tax treaties and tax credits

Thailand has double tax agreements with many countries. A treaty does not make income tax-free. It decides which country has the main right to tax each type of income and normally allows a credit for tax already paid in the other country, so you pay the higher of the two rates and not both. The credit usually has to be claimed on the return, with proof of the foreign tax paid, and it is not applied automatically.

Americans and some other nationalities are taxed on worldwide income by their home country too, so they have a second return to think about, and the credit works in both directions. Ask an adviser who knows both systems.

Rates, filing and deadlines

Thai personal income tax is progressive, from 0 percent up to 35 percent, after allowances and deductions. The tax year is the calendar year. The annual return for an individual with income other than salary alone is form PND 90, and the paper deadline is 31 March of the following year. Online filing has recently run about a week longer, to 8 April for the 2025 tax year, but check the date each year.

You need a Thai tax identification number to file, which you can obtain at a Revenue Department office, and the process is in Thai, so many expats use an accountant. One specialist firm states that a single person with less than 120,000 baht of assessable income in a year, or a married person with less than 220,000 baht, does not need to file. Check the current thresholds before you rely on this, and remember that tax can still be due on higher amounts.

Planning questions to ask an adviser

• How many days will I be in Thailand this year, and can I stay under 180?
• Which of my income is assessable when I bring it in, and when was it earned?
• What does the treaty with my home country say about my pension?
• Can I claim a tax credit, and what proof do I need?
• Do I need to file, and what is the deadline this year?

Thai tax authorities can ask questions about large transfers, so keep records of where your money comes from, as the money and banking guide explains.