← Guides / Thailand

Thailand Investment Income Guide

Thailand taxes investment income through a combination of withholding at source and annual IIT reporting. Dividends from SET-listed companies are subject to 10% WHT — the taxpayer may accept this as final or elect to include dividends in IIT and claim a 10% tax credit. Interest income from bank deposits and corporate bonds is subject to 15% WHT. Interest on government bonds is exempt. SLM (Superior Longevity Mutual) funds offer tax-advantaged savings. The Stock Exchange of Thailand (SET) is the primary market. All amounts in THB.

Thailand's treatment of investment income depends on the type of income and the taxpayer's residency status. The Revenue Department (กรมสรรพากร) administers the system through withholding agents (brokers, banks, companies). For related guidance, see our Personal Tax Guide →, Capital Gains Guide →, and Corporate Tax Guide →.

Dividends — 10% WHT (or IIT Inclusion with Credit)

  • Withholding tax: Dividends paid by companies listed on the SET/MAI are subject to 10% withholding tax at source. The taxpayer has two options:
  • Option A — Final tax (10% WHT): Accept the 10% withholding as a final tax. The dividends are not included in the annual IIT return, and no further tax is due. This is simple and benefits high-income taxpayers whose marginal rate exceeds 10%.
  • Option B — IIT inclusion with 10% credit: Include the gross dividend (before WHT) in assessable income on the annual IIT return. A 10% tax credit (representing the corporate tax underlying the dividend) is then available to offset the IIT liability. If the credit exceeds the tax due, it is not refundable but can reduce other tax. This option benefits low-income taxpayers with a marginal rate below 10%.
  • Unlisted company dividends: Dividends from unlisted Thai companies are also subject to 10% WHT. The same two options apply.
  • Non-residents: Dividends paid to non-resident individuals are subject to 10% WHT (final tax, may be reduced under a Double Tax Agreement).
  • Corporate shareholders: Dividends received by Thai companies from other Thai companies are generally exempt from CIT (if the recipient holds at least 25% of the payer or the dividend is from SET-listed shares and the payer has not claimed a tax deduction for the dividend).

Interest Income — 15% WHT (Banks, Bonds)

  • Bank deposits: Interest on savings accounts, fixed deposits, and other bank deposits is subject to 15% withholding tax at source. This is generally a final tax for individuals — the interest is not included in the annual IIT return.
  • Corporate bonds and debentures: Interest payments on corporate bonds and debentures issued by Thai companies are also subject to 15% WHT (final for individuals).
  • IIT inclusion option: Taxpayers whose marginal rate is below 15% may include interest income in their IIT return and claim the 15% WHT as a credit to obtain a refund of the excess withholding.
  • Non-residents: Interest paid to non-residents is generally subject to 15% WHT (may be reduced under DTA).

Government Bonds — Exempt

  • Interest on government bonds (พันธบัตรรัฐบาล) and Bank of Thailand bonds is exempt from personal income tax (including withholding tax). This exemption encourages individual investment in government debt.
  • State enterprise bonds: Interest on bonds issued by state enterprises (e.g., EGAT, PTT) may also be exempt if designated by the Ministry of Finance.
  • Savings bonds: Government savings bonds (ออมทรัพย์รัฐบาล) issued under specific programmes are fully tax-exempt for individuals.

SLM Funds and Thai Market Overview

  • SLM (Superior Longevity Mutual) Funds: Introduced as part of Thailand's retirement savings framework, SLM funds allow tax-deductible contributions of up to THB 200,000 per year (combined with other retirement savings under the THB 500,000 cap). The funds invest in a mix of domestic and international assets and have a 10-year holding period.
  • SET (Stock Exchange of Thailand): Thailand's primary stock exchange, the SET, lists over 800 companies with a total market capitalisation exceeding THB 20 trillion. Key indices include the SET Index, SET50 (large-cap), SET100, and the mai Index (for small and medium enterprises).
  • Deductible fund contributions: Contributions to RMF, SSF, SLM, provident funds, and NPS are deductible (see Personal Tax Guide for limits).
  • Mutual fund distributions: Capital gains distributed by Thai mutual funds to individual investors are generally tax-exempt for SET-listed securities held by the fund. Dividend distributions from Thai mutual funds follow the same 10% WHT treatment as corporate dividends.

Foreign Investment Income

  • Foreign dividends and interest: Thai tax residents must include foreign-sourced investment income in their IIT return (subject to the remittance basis — tax is due if the income is brought into Thailand in the same year). Foreign tax credits are available for tax paid abroad.
  • New remittance rule (2024): As of 2024, Thai tax residents are required to report all foreign-sourced income (including investment income) on the annual return, regardless of remittance. Tax is assessed on the portion remitted to Thailand. Foreign investment income brought into Thailand in a subsequent year is not subject to Thai tax (if it was earned before the new rules for certain categories).
  • Double Tax Agreements: Thailand has DTAs with over 60 countries, reducing withholding rates on cross-border dividends (typically 10–15%), interest (10–15%), and royalties (5–15%).