Inheritance and Estate Tax in Thailand

Thailand introduced a formal inheritance tax with the Inheritance Tax Act B.E. 2558, gazetted on 5 August 2015 and effective from 1 February 2016. Before that date, Thailand levied no dedicated estate or inheritance tax, and wealthier families routinely transferred assets during their lifetimes to avoid succession-related levies. Parliament paired the Inheritance Tax Act with amendments to the Revenue Code (Revenue Code Amendment Act No. 40 B.E. 2558) to introduce a companion gift tax on lifetime transfers, closing the most obvious avoidance route. Both pieces of legislation remain in force as of 2026 with no announced rate or threshold changes. Authoritative current-rate confirmation comes from PricewaterhouseCoopers' Thailand individual tax summary, last reviewed February 2026 (taxsummaries.pwc.com), and the Revenue Department's own published English translation of the Inheritance Tax Act (rd.go.th).

Who is subject to Thai inheritance tax?

Liability under the Inheritance Tax Act is determined by the heir's relationship to Thailand, not the decedent's. Four categories of taxpayer are liable:

1. Thai nationals, regardless of where they reside, for assets situated inside or outside Thailand.
2. Non-Thai nationals who are resident in Thailand under the Immigration Act, for assets inside or outside Thailand.
3. Non-Thai nationals who are not resident in Thailand, but only in respect of assets situated within Thailand (Thai-situs assets).
4. Juristic persons registered in Thailand or companies with more than 50% Thai shareholding, for assets inside or outside Thailand.

The practical consequence for expatriates and foreign property owners is significant: a foreign national who has never set foot in Thailand but inherits a Thai condominium, securities account, or registered vehicle with a value exceeding THB 100 million is squarely within scope. The tax attaches to the asset's location, not the heir's passport. Corporate heirs are equally caught where Thai-ownership thresholds are met. Confirmed by Mahanakorn Partners Group (mahanakornpartners.com) and PDLegal Thailand (pdlegal.co.th).

What are the tax rates and the THB 100 million threshold?

The Act imposes a flat-rate tax on the portion of an inheritance that exceeds THB 100 million received from any single testator. The threshold is applied per benefactor, not per estate: if a beneficiary inherits from two separate deceased individuals, each THB 100 million exemption applies independently. Only the excess above the threshold is taxable.

Two rates apply depending on the heir's relationship to the decedent:

Assets within scope include immovable property (land and buildings), listed and unlisted securities, bank deposit accounts and financial instruments, registered vehicles (motor vehicles, vessels, aircraft), and other financial assets prescribed by Royal Decree. Assets explicitly outside scope include life-insurance proceeds paid directly to a named beneficiary, employment entitlements such as provident-fund payouts, and digital assets, which sit in a separate regulatory category. Charitable foundations, educational institutions, religious organisations, government agencies, and entities with United Nations status are wholly exempt on inherited assets, as are legacies from decedents who died before 1 February 2016. Confirmed by PwC (taxsummaries.pwc.com) and Aphiwat Bualoi Law Office (aphiwatlaw.com).

How and when must the inheritance tax return be filed?

A beneficiary whose inheritance from a single testator exceeds THB 100 million must file an inheritance tax return and pay the tax within 150 days of the date on which the inheritance is received. The Revenue Department's Supreme Court Decision No. 2656/2567 clarified that the date of receipt is deemed to be the date of the decedent's death -- not the date funds are later withdrawn from a bank account or a property transfer is registered at the Land Department. Valuation, and the clock, both start from the death date.

The return form is available on the Revenue Department's English-language website (rd.go.th) and is submitted at the Revenue Department branch office covering the area where the inherited property is located or the heir is domiciled. Payment and filing occur simultaneously; there is no separate payment extension mechanism.

Penalties for late filing are prescribed by the Act itself. Where a return is filed and tax paid after the 150-day deadline, a surcharge equal to twice the amount of tax payable applies automatically, plus an additional monthly charge of 1.5% of the outstanding tax calculated from the date the filing deadline expired. Separate criminal fines of up to THB 500,000 may apply in cases of deliberate non-compliance. There is no voluntary disclosure mechanism equivalent to some other jurisdictions' streamlined programmes.

What is the companion gift tax and how does it work?

Revenue Code Amendment Act No. 40 B.E. 2558, effective 1 February 2016 simultaneously with the Inheritance Tax Act, subjects certain lifetime gifts to personal income tax (PIT) under the Revenue Code. The mechanism is not a standalone gift-tax statute but rather an extension of the PIT framework that grants a capped exemption and caps the marginal rate at 5% for qualifying transfers. PwC's Thailand individual income-determination summary, reviewed February 2026, confirms the current thresholds (taxsummaries.pwc.com).

Three exemption tiers apply annually, measured per recipient per tax year:

• THB 20 million: Gifts from parents to legitimate children (immovable property only) or gifts for maintenance/patronage from ascendants, descendants, or spouses. Amounts above THB 20 million per year are subject to PIT, but the recipient may elect a flat 5% rate on the excess rather than applying progressive PIT rates of up to 35%.
• THB 20 million: Gifts made under a moral obligation from ascendants, descendants, or spouses (maintenance-type transfers for movable property). Same 5% election available on excess.
• THB 10 million: Ceremonial or customary gifts made on occasions in accordance with established custom from persons who are not ascendants, descendants, or spouses. Any amount above THB 10 million per year is taxable at 5% flat (by election) or at progressive rates.

The gift-tax rules apply to Thai tax residents. For foreign-source gifts, a Thai resident is only taxable on amounts remitted into Thailand in the relevant tax year (subject to the updated remittance rules under Departmental Instruction Por 161/2566 from 1 January 2024 for future transfers). Sherrings Chartered Accountants (sherrings.com) and PDLegal Thailand (pdlegal.co.th) confirm the exemption tiers and the 5% election.

How does the spouse exemption work in practice?

The spousal exemption under the Inheritance Tax Act is unconditional and has no monetary cap. A legally married spouse who inherits any amount from the deceased partner pays zero inheritance tax, regardless of the estate's size. The exemption applies only to lawfully married spouses, not to common-law or de facto partners. Thailand does not currently recognise same-sex marriage for inheritance-tax purposes, meaning only opposite-sex married couples benefit from the full exemption at present.

The gift-tax framework extends a parallel benefit: transfers between spouses during their lifetimes fall within the THB 20 million annual maintenance-and-patronage exemption. Transfers above that figure in a given tax year are taxable, but the 5% election rate applies to the excess. Given the interplay between the inheritance and gift-tax rules, married couples with substantial Thai-situs assets often structure inter-vivos transfers carefully -- a matter for qualified local counsel.

Thailand's inheritance and gift-tax framework touches far fewer estates than the headline figures might suggest: Revenue Department data shows annual collections of only THB 0.4 to 1.5 billion, reflecting how few estates clear the THB 100 million threshold. For individuals and families with cross-border holdings, however, the territorial reach of the law -- particularly its application to non-resident foreign heirs inheriting Thai property -- creates exposure that is easy to overlook. The Thailand country overview sets this within the broader Thai tax environment. The interaction of inheritance, gift, and personal income tax rules, combined with treaty positions and local property-registration requirements, makes this an area where working with a qualified tax professional who understands both Thai Revenue Department practice and cross-border succession law is the appropriate starting point.