A detailed guide on pensions, dividends, interest, and foreign income tax credits under Thai tax law.

With the strict enforcement of Thailand’s foreign income remittance rules under Revenue Department Order Por. 161/2566, the primary mechanism protecting expats from double taxation is Thailand’s extensive network of Double Tax Agreements (DTAs), currently spanning over 60 countries (including the US, UK, Australia, Canada, Germany, France, and Japan).

1. The Two Primary Mechanisms of DTAs

DTAs operate primarily in two ways to ensure taxpayers do not pay full tax twice on the exact same income stream:

• Mechanism A: Primary / Exclusive Taxing Rights

  Certain types of income are designated as taxable only in the source country or only in the country of tax residence. For instance, public government pensions are almost universally taxed exclusively by the paying government.

• Mechanism B: Foreign Tax Credit (FTC) Relief

  If both countries hold taxing rights, the tax resident pays tax in the residence country (Thailand) but receives a credit for tax legally paid to the source country, up to the amount of Thai tax due on that same income.

2. Treatment of Key Income Types Under Common DTAs

Income Source	Standard DTA Treatment	Practical Outcome in Thailand
US Social Security	Taxable exclusively by the US under Article 19(2) of US-TH DTA.	Exempt from Thai PIT even when remitted to Thailand.
Government / Civil Service Pensions	Taxable exclusively by the paying country (e.g., UK Crown Pensions).	Exempt from Thai PIT in almost all bilateral treaties.
Private & Occupational Pensions	Generally taxable in the residence country (Thailand) upon remittance.	Subject to Thai PIT; foreign tax credits apply if tax was withheld at source.
Foreign Investment Dividends & Interest	Source country levies withholding tax (often capped at 10–15%).	Remitted amount is taxable in Thailand, but foreign tax paid is credited.
Capital Gains (Real Estate)	Taxable where the real estate is physically located.	Tax paid abroad acts as a tax credit against Thai liability.

3. Step-by-Step: How to Claim DTA Relief in Thailand

1. Establish Tax Residency: Obtain a Certificate of Tax Residence (RO 22) from your local Thai Revenue Department office if requested by foreign authorities.

2. Collect Foreign Proof of Payment: Secure official tax assessment notices or foreign tax return certificates showing the exact amount of tax paid on the remitted income in your home country.

3. File Annual Return (P.N.D. 90): Declare the remitted assessable income during the annual tax filing period (Jan–Mar following the tax year) and submit foreign tax paid proof to claim tax credit offsets.

Important Note on Documentation: All foreign tax documents, statements, and withholding receipts must be clearly legible and translated into Thai if requested by the local tax officer during the annual assessment.

On 8/4/2026 at 8:09 AM, CharlieH said:

Mechanism B: Foreign Tax Credit (FTC) Relief

If both countries hold taxing rights, the tax resident pays tax in the residence country (Thailand) but receives a credit for tax legally paid to the source country, up to the amount of Thai tax due on that same income.

That's an incomplete answer. For example, under the US-Thai DTA, Thailand has "primary/exclusive taxation rights" on private pensions -- but under the "saving clause" of the DTA, the US has secondary taxation rights and thus can also tax this income, but must absorb a tax credit for the taxes paid to Thailand. Thus the "saving clause" effectively eliminates the "exclusive" taxation right of Thailand.

And, because of the "saving clause," which says the US has taxation rights regardless of what the DTA says -- the US always at least has secondary taxation rights in situations where it doesn't have "primary/exclusive" taxation rights. The example above, re private pensions, is such a case. So to say Thailand has to absorb a tax credit, when the DTA says they have "primary/exclusive" taxation rights -- is false.

Another situation under the DTA, where both countries have taxation rights, is rental income. Here, for property held in the US, a Yank living in Thailand, but receiving rental remittances from his property in the US -- has a primary taxation requirement to the US. But Thailand has secondary taxation rights. So in this situation, you'd declare your rental remittance income to Thailand -- but would take a tax credit against this with those taxes paid to the US.

So, rule of thumb when both countries can tax -- primary country keeps all the taxes; secondary country has to absorb a tax credit. Now, if Thailand wants to absorb a tax credit for US taxes paid on private pensions -- that's their prerogative. But why they would want to do this -- is beyond me.