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Thailand MST number guide

Thailand Tax Identification Number (TIN) format​

The Tax ID number (TIN) is a 13 digit number issued by the Revenue department.

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Frequently Asked Questions​

As a foreigner in Thailand, do I use my national ID as a TIN or must I apply separately?​

Thai nationals use their 13-digit national ID card number (บัตรประชาชน) as their personal TIN — no separate application is needed. Foreign nationals, however, receive a different 13-digit TIN issued directly by a local Revenue Department office. You must visit the office in person with your passport and proof of address (such as a lease agreement or letter from your employer). There is no fee. The 60-day application deadline runs from the date you first earn Thai-assessable income or, if already a tax resident (180+ days), from when you remit foreign income into Thailand. Failure to register on time carries a fine of up to THB 2,000. [1] [2]

Since January 2024, is foreign income I bring into Thailand always taxable?​

Yes — under Revenue Department Instructions Por. 161/2566 and Por. 162/2566, any foreign-sourced income earned on or after 1 January 2024 and remitted to Thailand becomes assessable income in the year of remittance, taxed at progressive personal income tax rates (5%–35%). Income earned before 1 January 2024 remains protected under the prior rules regardless of when it is remitted. Tax treaties (double taxation agreements) with over 60 countries may reduce or eliminate the Thai tax on specific income types, so you must check treaty provisions for your country of residence before filing. [1] [2]

My Thai business client withholds tax from my service invoice — which rate applies?​

The rate depends on whether you carry on business in Thailand. Thai companies paying a domestic supplier for services (hire of work) must withhold 3% at source. Payments to a foreign company that has no permanent establishment in Thailand — such as an offshore SaaS provider or overseas contractor — are subject to a final withholding tax of 15% on service fees, royalties, and interest (10% on dividends). If a double tax treaty applies, the treaty rate overrides the domestic rate, potentially reducing it to 5%–10%. The Thai payer must file form PND.54 and remit the withheld amount to the Revenue Department within 7 days of the following month. [1] [2]

Does a foreign digital service company need a Thai TIN if it only sells to Thai consumers online?​

Yes. Under the VAT on Electronic Services (e-Service) law effective 1 September 2021, any non-resident business providing digital services — apps, streaming, cloud software, online advertising — to non-VAT-registered Thai customers must register for VAT through the Revenue Department's VES portal (eservice.rd.go.th) once annual Thai revenue exceeds THB 1.8 million (approximately USD 50,000). Registration must occur within 30 days of crossing the threshold. The registered provider pays 7% VAT monthly but cannot issue a Thai tax invoice or claim input VAT credits — it is a pay-only obligation. Non-registration attracts a penalty of twice the tax due per month or THB 1,000 per month, whichever is greater. [1] [2]

Can a highly skilled foreign professional in Thailand pay a flat 17% income tax instead of progressive rates?​

Yes, but only through the Long-Term Resident (LTR) visa issued by the Board of Investment. The "Highly Skilled Professional" LTR category grants a flat 17% personal income tax rate on Thai-sourced employment income in lieu of the standard 5%–35% progressive brackets. To qualify, the applicant must earn at least USD 80,000 per year (or USD 40,000 with a master's degree or above in a target industry), be employed by a company in a BOI-designated sector, and hold health insurance covering at least USD 50,000. The 17% rate does not automatically apply — the employer must process a notification through the BOI. Other LTR categories (Wealthy Global Citizen, Wealthy Pensioner, Work-from-Thailand) receive a 0% Thai rate on foreign-sourced income but do not qualify for the 17% flat rate. [1] [2]

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