Foreign Income and the Thai Tax Return: What Expat and Remote-Worker Clients Need to Know About the Remittance Rule

Foreign founders and remote workers who move to Thailand arrive with a tax question that is usually asked late, often after the first money has already crossed the border: is the income I earn abroad taxable here? The answer used to be a comfortable “not if you leave it abroad until next year.” For income earned from 2024 onward, that answer no longer holds.

The foreign-founder opportunity described earlier in this series, the setup, the BOI application, the visa questions, is incomplete without a tax plan for the individual behind the company. A firm that raises the remittance rule early prevents an expensive surprise. A firm that learns it mid-conversation, or repeats an outdated rule, gives advice that costs the client money.

This article explains the framework, the point on which sources have been confused, and the records that decide the outcome. As with other regulatory topics in this series, the specifics come from secondary law-firm and advisory summaries, so a firm should confirm the position that applies to a given tax year with the Revenue Department before advising.

Residency Comes First

Thai personal income tax reaches different income depending on whether the individual is a tax resident. The commonly cited test is presence in Thailand for 180 days or more in a calendar year. A person who meets it is a resident for that year and is taxed on Thai-sourced income and on certain foreign-sourced income. A non-resident is generally taxed only on Thai-sourced income.

This makes counting days the first practical task, and it is a task founders often get wrong. Days spent on short trips, days spent across year-end, and the date of arrival all matter. A client who has been splitting time between countries cannot assume they are non-resident because they think of themselves as a visitor. The count is made from travel records, not from intention.

The Remittance Rule

For a resident, the key question is when foreign-sourced income is treated as assessable. Two Revenue Department rulings, Por. 161/2566 and Por. 162/2566, set the current position according to the sources reviewed.

Por. 161/2566, effective from 1 January 2024, reportedly treats foreign income that a resident brings into Thailand as assessable in the year it is remitted, regardless of the year in which it was earned. The older practice, under which income earned abroad in one year and remitted in a later year escaped Thai tax, no longer applies to income earned from 2024.

Por. 162/2566 is reported to clarify that this treatment does not reach foreign income derived before 1 January 2024. Money earned before that date is generally treated differently.

The practical consequence is that timing no longer works as a shelter. Earning income abroad and leaving it there until a later year does not take it outside Thai tax once it is brought in. A founder who draws a salary or dividends from an overseas entity, a freelancer paid by foreign clients, or a remote worker paid by a foreign employer may all have assessable income when it reaches a Thai account.

The Proposal That Is Not Law

Much of the confusion comes from a proposed relaxation. The idea, discussed since mid-2025, would exempt foreign income that is remitted in the year it is earned or the following year. Several advisers’ articles have described it in language that makes it sound imminent or in force.

According to the most recent sources reviewed, which report checks as late as October 2026, the proposed exemption has not been published in the Royal Gazette and therefore has no legal effect. One source describes the process as stalled after the dissolution of the House ahead of elections, and sources differ on the form the instrument might take and on the exact window it would create.

The honest message for clients is plain. The stricter rule is the one that applies today. A relaxation may come, but planning on the assumption that it will is a gamble, and a firm should not describe it as available. If the position changes, it will be announced formally, and the firm’s job is to check before each filing season.

The distinction to keep clear is between two different things: the 2024 rulings, which are in force, and the proposed exemption, which is not.

What Records Decide the Outcome

The remittance rule makes two facts critical: when and where each amount of income was earned, and when it was brought into Thailand. A client who cannot show these is poorly placed under any version of the rule.

For each remittance, the firm should be able to establish the date it arrived in Thailand, the amount, the account it came from, and the nature of the money: current-year income, earlier income, savings, a gift, a loan, or a return of capital. The distinction matters because not all money entering Thailand is assessable income. A founder who transfers savings accumulated before 2024 is in a different position from one who transfers this year’s earnings.

This is a records exercise first and a tax exercise second. Foreign bank statements, transfer confirmations, payslips from overseas employers, and dividend notices all form part of the evidence. A client who has mixed everything in one account, with salary, savings, and gifts commingled, has made the analysis harder and sometimes impossible.

Separate Rules for Some Visa Holders

Sources report that holders of certain Long-Term Resident visa categories enjoy a separate exemption on foreign-sourced income under a royal decree, distinct from the remittance-timing rules. Which categories qualify and on what conditions should be confirmed with the Board of Investment, as the visa article in this series explained that categories differ in other ways too.

For a client on one of those visas, the answer to the remittance question may be different, which is another reason the firm should ask early which visa the client holds. For a client who is not, the 2024 rulings apply.

Double Taxation and Treaties

A client taxed on the same income in two countries will want to know whether relief is available. Thailand has double taxation agreements with many countries, and credits or exemptions may apply depending on the treaty and the type of income. The detail varies by country pair and by income category, so this is an area where a firm should work from the specific treaty and, where the position is complex, bring in a specialist. The firm’s contribution at the early stage is to identify that the question exists, not to answer it from memory.

Making the Conversation Early

The intake questions are short and they pay for themselves. How many days does the client expect to spend in Thailand this year and next? Where do they earn income, and into which accounts is it paid? What do they plan to bring into Thailand, and when? Which visa do they hold? Do they hold savings or assets abroad that predate their move?

From those answers, the firm can advise on whether the client will be resident, which income is likely to be assessable, and how to keep records so that the position can be demonstrated. It can also flag when to bring in a specialist, such as for treaty relief or for a client with complex overseas holdings.

The conversation is also part of the foreign-founder relationship. A founder who is told early that the tax picture includes their personal income, and is given a clear plan, will see the firm as an adviser to them, not just to their company.

FirmFlow and the Remittance Record

The remittance question turns on dates, sources, and amounts scattered across foreign bank statements and transfer records. FirmFlow’s Document Analyser and matter record organise those into one chronological file per client, so the answer to which remittances were taxable can be built from evidence, not recalled from memory.

The rule is stricter than many clients assume and the relief that has been discussed is not law. A firm that tells clients so plainly, and keeps the records that let them demonstrate their position, is giving the kind of advice that foreign founders remember when their first Thai filing arrives.