Personal Income Tax & TIN for Foreigners

Section 41 of the Revenue Code treats a person who stays in Thailand for a total of 180 days or more in a calendar year as resident for that tax year. The days do not need to be consecutive, and the test is applied to each calendar year separately. Nationality and visa type do not by themselves decide residence; a retiree, a Destination Thailand Visa holder and an employee are all assessed on the same day count.

Every person, resident or not, is taxable on income from employment or business carried on in Thailand, or from property located in Thailand. The difference for residents is the treatment of foreign-sourced income brought into the country. A person who stays fewer than 180 days in a year is generally not taxed in Thailand on foreign income, even if some of it is remitted.

Because the count depends on actual presence, we start every engagement with the immigration travel record or passport stamps. Clients are often surprised to find they crossed the threshold in one year and not in another, which changes the treatment of remittances made in each year.

Revenue Department instruction Paw. 161/2566 provides that, from 1 January 2024, foreign-sourced income received by a tax resident and brought into Thailand is assessable in the year it is brought in, whether or not it was earned in the same year. Instruction Paw. 162/2566 clarifies that income earned before 1 January 2024 is not assessable when remitted later. In practice, the source of each transfer and the date the money was earned become the key questions.

Bringing money into Thailand can take several forms: bank transfers, card spending from foreign accounts, cash carried in, or payments made abroad on the resident's behalf. Not every movement of money is income — the return of capital, a loan or a gift may be treated differently — but the taxpayer should be able to explain and evidence the nature of each amount if asked.

Thailand has double taxation agreements with many countries. Depending on the treaty and the type of income, foreign tax already paid may be credited against Thai tax, or certain income, such as some government pensions, may be taxable only in the paying country. Some long-term resident visa categories also benefit from specific exemptions under royal decree; we check the current conditions for each client rather than assuming they apply.

Foreigners without a Thai identity number apply to the Revenue Department for a 13-digit Tax Identification Number, usually at the area revenue office for their address, with a passport, evidence of address and, where relevant, evidence of income. Foreigners who already hold a pink identity card for foreigners may use that number. Employers withhold tax on Thai salary monthly and issue a withholding certificate at the end of the year.

The annual personal income tax return is filed on form P.N.D. 90, or P.N.D. 91 for those whose only income is employment income, normally by the end of March of the following year, with additional time often allowed for online filing. Allowances and deductions, such as personal and spouse allowances or certain insurance premiums, depend on conditions set by the Revenue Department each year.

Late filing or underpayment can lead to surcharges and penalties under the Revenue Code. A filed return and tax receipt can also help with other matters: some immigration and work-permit processes, bank account reviews and visa applications in other countries ask for evidence of Thai tax compliance.

The simplest protection is to keep pre-2024 savings in a separate foreign account from income earned since 1 January 2024, and to keep statements that show balances at the end of 2023. When money is transferred to Thailand, a short note of its source and the year it was earned, kept with the bank record, makes any later explanation far easier.

Retirees should keep pension statements and any foreign tax certificates; remote workers should keep contracts and invoices showing where services were performed and who paid; investors should keep records of the purchase cost of shares or property sold, because tax may arise only on the gain. These records are also useful in the home country, where tax obligations may continue.

Couples should also consider each spouse's position separately. Thai tax residence is personal, so one spouse may be resident while the other is not in the same year, and a joint bank account used for remittances can make it harder to show whose income was brought in. Using separate accounts, or at least recording which spouse each transfer belongs to, keeps the position clear for both.

Those leaving Thailand permanently should not forget the tax side of departure. A final return may still be due for the year of departure, Thai bank accounts may need to be closed or kept for refunds, and some foreign authorities ask for evidence of Thai tax residence or non-residence when the person settles elsewhere. Planning these steps a few months ahead avoids having to deal with them from abroad.

Tax rules and Revenue Department practice change, and each client's facts differ. We give a written outline of the position for your year, prepared with qualified tax advisers where computation is needed, and we do not promise any particular tax outcome. A Free Preliminary Eligibility Review helps confirm whether you are likely to be resident and whether a filing may be required before you Request a Formal Quotation.