Tax in Bangkok: the day count that decides it resets every 1 January

Thailand taxes foreign money when you bring it in — but only if you were here long enough in the year the money was earned. Those are two different years, the day count between them starts again every New Year, and getting the order wrong is how people arrive at completely confident, completely inverted answers about their own position.

Compiled by the Town Wire News desk · Last verified October 2026 · How we made this

The sentence everybody repeats, and the word it leaves out

Ask around Bangkok and you will be told, with total confidence and in almost identical words, that if you spend more than 180 days in Thailand you are a tax resident, and that as a tax resident you pay Thai tax on money you bring into the country. Both halves of that are close enough to true to be repeated forever, and the gap between them is where the actual rule lives.

The rule is one sentence of the Revenue Code and it has been sitting there, in this shape, since 1959. Paragraph two of section 41 says that a resident of Thailand who in the previous tax year had assessable income under section 40 from employment or a business carried on abroad, or from property situated abroad, must pay income tax under this Part when that assessable income is brought into Thailand.

Read it slowly and you will notice that it contains two separate moments. There is a year in which the person was a resident and the income arose. There is a later act of bringing the money in. The section does not say they are the same year, and for a very long time nobody needed to ask, because the settled practice was that money remitted in a later year escaped entirely. Wait until January and the problem went away.

That is what changed. On 15 September 2023 the Revenue Department issued Departmental Instruction Por. 161/2566, which tells its own officers how to read the paragraph, and the reading it gives is that a resident who has foreign-source income in a tax year and brings it into Thailand in whatever tax year must include it in the computation for the year the money entered. Two months later Por. 162/2566 added a single sentence excluding income that arose before 1 January 2024. Both apply to money brought in from 1 January 2024 onwards.

So the deferral is gone, and it is gone in a specific way: not by making the remittance itself taxable, but by removing the requirement that the two moments fall in the same year. The two moments are still two moments. Everything difficult about this rule comes from people collapsing them.

The count is a calendar-year count, and it starts again

Take the day count first, because it is the part people think they already understand.

Paragraph three of section 41 reads: any person who is in Thailand for one period or several periods, aggregating to 180 days in any tax year, shall be deemed a resident of Thailand. The Thai verb is thueng, reaching. Day 180 is inside. The department’s Legal Bureau states the test the same way, as 180 days and above, and adds that nationality and race are irrelevant to it — the rule catches Thai citizens exactly as it catches everybody else.

We will note in passing that the department’s own English-language summary page on personal income tax describes a resident as someone in Thailand for periods aggregating to more than 180 days, which puts day 180 on the other side of the line. That is a translation looser than the statute, and the statute and the Legal Bureau agree with each other. If your year lands exactly on 180, take yourself to be resident.

The part that surprises people is what “in any tax year” does to a long stay. The Thai tax year is the calendar year. The count is per calendar year, and the department’s worked example makes the consequence explicit: a person in Thailand for 250 consecutive days, of which 100 fall in one year and 150 in the next, is not a resident in either of them, because in each individual year the total did not reach 180.

Two hundred and fifty days is eight months. It is more than long enough to sign a lease, get a phone number, learn where the good market is and feel entirely settled. And split the wrong way around a New Year, it produces two non-resident years in a row. The counter is not a rolling window and it does not remember December.

The mirror image is the trap in the other direction, and it is the one that catches people who arrive in the first half of the year. Land in February, stay through to the end of the year, and you cross 180 comfortably — in your very first, partial year. Nothing about the arrangement felt permanent. The count does not care.

Which year the residence test actually looks at

Now the part that inverts most of what circulates.

Everyone assumes the test is applied at the moment of transfer: if you are a Thai tax resident when the money lands, you are taxed. That is not what the department says, and it says the opposite in a published worked example rather than by implication.

The example: in the tax year 2567, Mr Ko was in Thailand for a total of 65 days. In that year he had assessable income from renting out property abroad. In the same year he transferred that rent into a Thai bank account. Does he pay Thai personal income tax on it? No — and the reason given is that he was not a resident of Thailand at the time the assessable income arose.

He remitted it. He remitted it in the very same year. It made no difference, because the first condition was never satisfied, and the two conditions are joined by an “and”. The department sets them out in exactly that shape: first, the person has foreign-source assessable income from 1 January 2024 onwards in a tax year in which they were in Thailand 180 days or more; second, the person brought that income into Thailand in that tax year or in any later one. Meet both and it is taxable in the year of arrival. Fail the first and there is nothing to fail the second against.

This has a consequence that matters far more to people moving to Bangkok than any of the discussion about deferral. Money you earned before you got here — in years when you were living somewhere else, working somewhere else, and nowhere near 180 days in Thailand — does not become taxable because you have now become a resident and have now moved it. The department puts that in a worked example too: a Thai national who lived in China from 2550, decided in 2567 to come home permanently, and brought the whole accumulated proceeds of her Chinese business with her, owes nothing, because the money came from income arising in years when she was not a resident of Thailand.

Read those two examples together and the architecture is clear. The rule is not a tax on transfers into Thailand. It is a tax on income that was earned while Thailand had a claim on you, collected at the point where the money finally arrives.

What “bringing it in” actually covers

Having established which income is in scope, the second condition is deliberately broad. The department defines bringing assessable income into Thailand as doing anything, by any method, to bring it in — and then names three: transferring it through a bank account, transferring it through an online system, and carrying it into the country on your person.

There is no reading available in which this is a rule about wire transfers. Cash in a bag is named. What the definition does not do is convert every inbound payment into income; it only fixes the moment at which income that already exists, and already passed the first test, becomes taxable here.

Which is why the next question is the one that does most of the work in practice.

Capital, gains, and the part that is simply yours

Money is not income. The department says so three separate ways, and they are worth having individually because mixed transfers are the normal case.

First, round trips. Transfer 200,000 baht out to an investment account abroad, close the account later, bring the 200,000 back: not assessable income, and no tax on bringing it in. Your own capital returning to you is not a gain.

Second, principal and interest travelling together. Put money on deposit abroad and bring back both parts, and the principal is untaxed while the interest is assessable, being interest income under section 40(4)(a) of the Code. The remittance is split, not treated as a lump.

Third, gains are computed on the transaction, not on the balance. Assessable income is only the part in excess of what was invested: sale price less cost at acquisition, transaction by transaction, with any generally accepted accounting method for recording cost that suits the asset. And the department is explicit that where a client invests more each year and brings part of it back along the way, it is the taxpayer who assesses, on the actual facts, how much of the amount remitted is income and how much is capital.

That last sentence is doing something quietly significant. It puts the characterisation of your own remittance on you. Nobody at the bank is deciding whether that transfer was principal or profit; the position you take is your position, and it is the position you would have to be able to show.

Then there is the timing of gains, which introduces the third clock. An unrealised gain is not assessable income at all. The department’s worked example runs across three years: shares bought abroad in March 2567 at 1,000 baht each stand at 1,100 on 31 December, and that increase is not income because nothing has been sold. Eighty of the hundred shares are sold on 1 June 2568 at 1,200, producing realised income in 2568 under section 40(4)(ch); the twenty unsold shares still produce nothing. The gain from that June sale is brought into Thailand in 2569, and it goes into the personal income tax computation for 2569.

One holding, three different years doing three different jobs. The year you bought it does nothing. The year you sold it decides that income exists and how much. The year the money arrived decides which return it goes on.

The exchange rate, and the quiet way it moves the number

One line in the department’s answers settles a question that most guides do not raise at all: which exchange rate is used to compute the assessable income? The rate on the day the income is brought into Thailand.

Not the rate on the day you earned it. Not an average for the year. The day it lands.

So the baht figure your Thai tax is calculated on is a function of when you chose to move the money, and it can differ from the baht value of the same income on the day it was earned in either direction. That is not a loophole and it is not a penalty — it is just a rule, and it is one of the very few places in this subject where an ordinary decision about timing has a direct arithmetical effect that you can actually see.

What stays exempt, and what a treaty does

The rule reaches assessable income under section 40, categories (1) to (8). But income that the Revenue Code exempts stays exempt when it arrives from abroad. The department names two examples: inheritance, and maintenance or gifts received from ascendants, descendants or a spouse, up to 20 million baht in the tax year. Money that was never assessable does not become assessable by crossing a border.

The double-taxation question gets a clear answer with a condition attached. Where income brought into Thailand has already been taxed abroad, the department says there is no double taxation, because a Thai tax resident may credit the foreign tax against the Thai tax due in the tax year the income is brought in — and the credit is available under the provisions of the double taxation agreement between Thailand and that country.

Two things follow. The credit rides on a treaty, so which country the income came from is a live question, not a formality. And the credit is claimed in the year of remittance, which may be a different year from the one in which the foreign tax was paid.

Thailand has a substantial treaty network and the Revenue Department publishes the list. We could not read it: the table on that page is loaded by script and the page we received contained only its column headings. We are not going to print a count we did not see, and if your position turns on a particular country you will want the table itself rather than anybody’s summary of it.

Filing starts long before paying does

Here is the part that catches people who have correctly worked out that they owe nothing.

Section 56 of the Revenue Code puts the duty to file on every person — excepting minors and those the court has found incompetent — who in the previous tax year had assessable income above a threshold, and the thresholds are these: without a spouse, more than 60,000 baht; without a spouse but with employment income under section 40(1) alone, more than 120,000 baht; with a spouse, more than 120,000 baht; with a spouse and employment income alone, more than 220,000 baht. The return goes in within March.

Every one of those numbers is a gross assessable income figure. None of them is a figure for tax owed. Deductions and personal allowances lift the point at which tax actually begins well above 60,000 baht, which means there is a wide band — and for a lot of people it is the band they are actually in — where the duty to file exists and the liability is zero.

Remitted foreign income that passed both conditions is assessable income and counts towards the threshold. So a resident who brings in a modest amount of post-2024 foreign earnings can land inside the filing duty while owing nothing at all.

The identification number is a separate machine again. The Revenue Code itself does not set a deadline for getting one: section 3 Undecim simply empowers the Director-General, with the Minister’s approval, to require taxpayers and payers of income to obtain and use a Tax Identification Number in accordance with rules the Director-General prescribes, and section 3 Duodecim attaches a fine not exceeding 2,000 baht to breaching an announcement made under it. The 60-day window that everybody quotes lives in that announcement rather than in the Code, and we did not read the announcement. Treat the 60 days as the settled common account, and the 2,000 baht as the figure we did read.

The relief that is not law

Since 2025 there has been a great deal of writing about a measure that would exempt foreign income remitted into Thailand in the same calendar year it was earned, or in the immediately following year. Income earned in 2025 and brought in during 2025 or 2026 would be free; anything remitted later would stay taxable on the ordinary progressive scale. It has been approved in principle, reported in detail, and explained by every professional firm with a Bangkok office.

It has not, as at our last check, been published in the Royal Gazette. A royal decree or a ministerial regulation still has to be made and published, and the legislative machinery around it was paused across the February 2026 election and the formation of a government. Everything we have on it is secondary — professional-firm commentary, not an instrument.

We are stating that plainly because the failure mode here is expensive and asymmetric. A remittance made now on the strength of a draft is assessed under the law that exists now. If the final text lands with a different effective date, or a narrower scope, the transfer has already happened and the liability was always there. There is no version of this where waiting for the Gazette costs you more than not waiting for it.

What this looks like from a Bangkok flat

Strip the machinery out and a handful of practical shapes remain.

If you arrived this year and your savings were built up before you came, those savings are outside the rule and always will be, however much later you move them. Nothing you do in Thailand changes the year they arose in.

If you are living here and earning abroad now, the first condition is meeting itself every year you stay past 180 days, and the only remaining question is when the money crosses. The old strategy of parking a year’s income and moving it in January no longer does anything: Por. 161 removed exactly that.

If you hold investments abroad, the year of sale is the year that creates income, and the year of arrival is the year it is assessed. A holding sold in a year when you were resident produces income even if the proceeds sit abroad for years afterwards — and it will be assessed whenever they arrive.

If you split your year between two countries, the arithmetic of the calendar boundary is worth doing deliberately rather than discovering afterwards. The difference between 179 and 180 days is a whole regime, and it is decided by dates you can see in your own passport.

And if you bank in Thailand at all, it is worth knowing that this and the anti-money-laundering machinery are separate systems with separate logics. The tax rule cares about the year income arose; your bank’s customer due diligence cares about where you live now. We wrote about the second one in opening a Thai bank account, where the word that decides everything is residence, and it is not the same test as this one.

Questions people actually ask

I have been here nine months but they were split across two years. Am I resident?

Probably not, in either year. The department’s worked example is precisely this: 250 consecutive days, 100 in one year and 150 in the next, gives a non-resident year twice. Count each calendar year separately.

I was not resident when I earned it but I am resident now. Does bringing it in trigger tax?

No. The residence test is applied to the year the income arose. The department’s 65-day example remitted in the same year and still owed nothing.

Does the rule apply to me if I am not Thai?

It applies without reference to nationality or race — the Legal Bureau says so in terms. It catches Thai citizens returning from abroad on exactly the same basis.

I brought in a mixed transfer of savings and profit. How is it split?

You assess it yourself on the actual facts, and only the part in excess of what you invested is income. The department states both halves of that.

My shares went up but I have not sold. Is that income?

No. An unrealised gain is not assessable income. It becomes income in the year you sell, and is assessed in the year the money arrives.

I already paid tax on it abroad. Do I pay again?

You may credit the foreign tax against the Thai tax in the year of remittance, where the double taxation agreement between Thailand and that country provides for it. Which country it came from matters.

Do I need to file if I owe nothing?

Possibly. The section 56 duty is triggered by gross assessable income at 60,000 baht for a single person, well below where tax starts.

Is it true that the tax has been scrapped for money brought in the same year?

A measure to that effect has been drafted and widely reported. It was not in the Royal Gazette when we last checked, which means it is not in force.

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