Thailand's 180-Day Rule: When Foreign Income Gets Taxed

If you split your year between Thailand and somewhere else, one number quietly decides whether Thailand can tax your overseas salary, pension, dividends or crypto gains: 180. Cross that line and you're a Thai tax resident — often without meaning to, and often without anyone telling you.

The part that catches people out isn't the residency itself. It's that residency plus a bank transfer can turn money you earned abroad into taxable income in Thailand. Since a rule change that took effect in 2024, and with a further reform still hanging in draft in 2026, a lot of long-stay expats, digital nomads and retirees are unsure where they actually stand.

This guide walks through exactly how the Thailand tax residency 180 days foreign income rules work right now: what counts as a day, when overseas money becomes taxable, what stays exempt, and what the proposed 2026 change would (and wouldn't) fix. It's general information, not personal tax advice — your treaty situation and income mix matter, and the authority with the final word is the Revenue Department of Thailand (กรมสรรพากร).

What makes you a Thai tax resident?

A Thai tax resident is anyone physically present in Thailand for 180 days or more during a single calendar year (1 January to 31 December).

That threshold comes from Section 41 of the Thai Revenue Code. Three things about it trip people up:

• The days don't need to be consecutive. Thailand adds up every day you spend in the country across the whole year. Three separate two-month stays count exactly the same as one six-month stay.
• It resets every year. Thailand counts on a calendar-year basis, not a rolling 12 months. Each year is judged entirely on its own — hitting 180 days one year has no bearing on the next.
• It's about presence, not visa type. Your visa category (tourist, education, retirement, Long-Term Resident, Elite/Privilege) doesn't change the day count. What matters is where your body physically is.

How do I count the days?

Count every day any part of which you were in Thailand. The safest evidence is your passport entry and exit stamps plus airline records. If you're anywhere near the line — say 170–185 days — keep a simple log of arrival and departure dates. When residency is contested, the burden of showing where you were falls on you, not the tax office.

A quick self-check:

1. Add up all days spent in Thailand this calendar year, arrival and departure days included.
2. If the total reaches 180 or more, you are a tax resident for that year.
3. If you stayed 179 or fewer, you are a non-resident for that year — Thailand can only tax income sourced inside Thailand.

When does my foreign income actually get taxed?

This is where residency turns into a real bill — or doesn't. Being a resident does not automatically mean Thailand taxes your worldwide income. Two conditions have to line up:

1. You are a Thai tax resident (180+ days) in the year the income is earned, and
2. You remit that income into Thailand — i.e. money physically enters the country, for example a transfer to a Thai bank account or spending brought in.

Definition: "remittance" means bringing the money into Thailand. Income that stays in an overseas account is not taxed by Thailand under the current rules, however large it is. The tax is triggered by the transfer, not by the earning.

This is a change from how Thailand operated for years. Historically, foreign income was only taxed if you brought it in during the same year you earned it — so parking money for a year washed it clean. That loophole was closed by Departmental Instruction Por.161/2566, with Por.162/2566 confirming the new interpretation applies only to income earned from 1 January 2024 onward.

What kinds of foreign income count?

If it's remitted by a resident and was earned from 2024 on, assessable foreign income typically includes:

• Salary and employment income earned abroad
• Pensions and annuities paid from overseas
• Dividends and interest from foreign investments
• Rental income from property abroad
• Capital gains, including gains on shares and crypto sold overseas

What foreign money is NOT taxed?

• Anything earned before 1 January 2024. This protection is permanent — pre-2024 savings and income remain exempt whenever you remit them, provided you can document that they were earned before that date.
• Income you never bring into Thailand. Under the current remittance system, money kept offshore isn't assessable.
• Income in a year you're a non-resident. If you stayed under 180 days in the year the income was earned, remitting it later generally doesn't make it Thai-taxable.

Because pre-2024 money is treated so differently, keeping dated evidence — account statements showing balances as of 31 December 2023, sale contracts, payslips — is the single most useful thing you can do to protect yourself.

How much tax would I pay on remitted foreign income?

Remitted foreign income is added to your other Thai assessable income and taxed at the standard progressive personal income tax rates, which run from 0% to 35%. The first slice of net income is tax-free, and rates climb in eight bands (figures from the Revenue Department):

Before the rate is applied you can reduce the taxable base with allowances — including a personal allowance of THB 60,000 and various deductions for spouse, children, insurance and the like. The exact allowances change from time to time, so confirm the current figures on the Revenue Department's site when you file.

Will I be taxed twice?

Often not. Thailand has double tax agreements (DTAs) with more than 60 countries. Where the same income has already been taxed abroad, a DTA usually lets you claim a foreign tax credit against your Thai liability. The catch: you must produce clear evidence of the foreign tax paid — foreign tax certificates or filings — and the credit applies to the same income taxed in both places. Treaty relief is not automatic; you claim it, and you prove it.

How and when do I file?

Thailand runs on self-assessment. Nobody withholds tax on the money you wire in — it's on you to declare it.

• Get a Thai Tax Identification Number (TIN) if you have assessable income to report. Residents with foreign income to declare need one to file.
• File form PND 90 (the return used for income beyond simple employment income) for the previous calendar year.
• The paper filing deadline is 31 March. Online filing through the Revenue Department's e-filing portal typically runs a little later, but treat 31 March as your anchor date.
• Keep your records — remittance dates and amounts, proof of when income was earned, and any foreign tax paid.

Filing late or under-declaring can trigger surcharges and penalties, so if your situation is at all complex (multiple income types, treaty claims, large one-off remittances), it's worth a session with a Thai-licensed tax adviser before the deadline.

What is the proposed 2026 change — and can I rely on it?

Thailand's Revenue Department has floated a relief measure aimed at encouraging people to bring money in. Under the draft, foreign-sourced income earned from 2024 onward would be exempt if remitted in the same calendar year it's earned, or in the immediately following year. Money left offshore longer and then brought in would fall back into the taxable net.

In plain terms: income earned in 2025 and remitted in 2025 or 2026 would be exempt; the same income sat on until 2027 would be taxable.

The crucial caveat: as of mid-2026 this is a proposal, not enacted law. The draft still needs to clear Cabinet and be reviewed by the Council of State before it becomes a binding ministerial regulation. Several practical details remain unsettled. A separate, more far-reaching idea — taxing residents on worldwide income regardless of whether it's remitted — has also been discussed but not adopted.

So plan around the rules that are actually in force today, and watch the Revenue Department's announcements rather than the headlines.

Conclusion

The rule to internalise is simple: 180 days in a calendar year makes you a Thai tax resident, and once you're resident, foreign income earned from 2024 onward becomes taxable when you remit it into Thailand — while pre-2024 money and money kept offshore stay outside the net for now. The most valuable move you can make today is to track your days and keep dated records of when your foreign income was earned, so you can prove your position if the Revenue Department ever asks. If your income mix or treaty situation is complicated, confirm the current allowances and the status of the 2026 reform directly with the Revenue Department of Thailand, or a Thai-licensed tax professional, before you file.