Understanding Personal Income Tax in Thailand: Are You a Tax Resident?

Tax season is here, and as we finalize tax reports for 2024—including those for both Thai and non-Thai staff—I realized that many people may be unsure about their tax obligations in Thailand. Some of our team members are filing their taxes for the first time, so we consulted the Chiang Mai Revenue Office to clarify the requirements. Their guidance was extremely helpful, and I wanted to share some key takeaways.

Determining Your Tax Residency Status

Your tax obligations in Thailand depend on how many days you spend in the country:

• More than 180 days in a tax year → You are considered a Thai tax resident and must pay tax on your worldwide income (both Thai and foreign earnings).
• Less than 180 days in a tax year → You are classified as a non-resident and only need to pay tax on income sourced in Thailand.

💡 Important: Your tax residency status is not linked to your visa type.

Short Stays & Tax Obligations

Even if you stay in Thailand for less than 180 days, you are still required to pay tax on any income derived from Thai sources—including salary, rental income, or service fees paid from Thailand.

For example, if you travel for business and spend less than half the year in Thailand but receive a Thai-paid salary, you are still liable for Thai income tax.

Proving You Stayed Less Than 180 Days

If you need to confirm that your stay in Thailand was under 180 days (for tax or immigration purposes), you will typically need to provide:

1. Explanation Letter
   • A formal letter explaining why your stay in Thailand did not exceed 180 days.
   • Include your entry and exit dates for the tax year.
2. Copy of Passport
   • Personal information page
   • Visa page and all entry/exit stamps for Thailand

💡 In some cases, additional documents may be requested. If so, the Revenue Office will notify you accordingly.

Additional Tax Considerations

Everyone’s tax situation is different. Here are some factors to keep in mind:

• If you’re over 60 years old, you may qualify for special tax deductions.
• If you’ve contributed to healthcare for 10 years, you may be able to deduct up to 100,000 THB.
• If you’re American, you may also need to file taxes in the U.S., but Thailand and the U.S. have a tax treaty—so consult a tax expert.

Final Advice: Speak to a Tax Accountant

To ensure your taxes are handled properly:

✅ Consult a tax accountant to confirm your obligations and deductions.
✅ Verify that your employer is making WHT (Withholding Tax) payments on your behalf—ask for the certificates.
✅ If your company is handling your tax returns, review the data they submit to avoid mistakes. At the end of the day, you are responsible for your own tax filings.

🔹 Trust is great, but mistakes happen—always double-check to avoid surprises.