Personal Income Tax for Foreigners in Thailand: Who Pays, Tax Residency, Rates, Deductions & the PND.91 Return

First: who owes personal income tax in Thailand

• Thai-source income can be taxable: income from employment, services or business earned in Thailand is in principle taxable there, whether or not you're a tax resident
• Residency is by day count: staying 183 days in a tax year (calendar year) makes you a tax resident
• Foreign income: residents may also be taxed on foreign income remitted into Thailand, with rules tightening recently — see tax residency and foreign income
• Work compliantly first: working in Thailand needs a work permit — see the work permit guide

How rates and common deductions work

• Progressive 0%–35%: taxable income is banded, higher income means a higher marginal rate, with a tax-free/low band at the bottom
• Deduct first, then tax: taxable income is total income minus expense deductions, the personal allowance and various deductions (self/spouse/children, parental support, social security, certain insurance and provident funds, home-loan interest, etc., per rules)
• Employers withhold monthly: employees' wages are withheld monthly by the employer (PND.1), reconciled in the annual return
• Figures change: exact bands, allowances and deduction limits follow the Revenue Department's rules for the year — don't use old numbers

How to file, and which form

• PND.91: individuals with employment income only commonly file the annual PND.91
• PND.90: those with other income types (business, rent, investment) use PND.90
• Filing window: personal tax is usually filed early the next year through March (online may extend slightly) — don't be late
• A Thai TIN: you need a taxpayer identification number before filing
• Rent and other income: landlord rental income filing is in the landlord guide; crypto gains in the crypto tax guide

Can I get a refund? How

• Yes, refunds happen: if tax withheld/prepaid over the year exceeds your liability, you can claim a refund after the annual return
• Common cases: mid-year resignation, deductions not fully reflected in withholding, or income below the withholding estimate
• Claim your deductions honestly: listing all eligible deductions in the return is the legitimate way to lower tax and recover overpayments
• How this differs from shopping VAT refunds is in the tax refund guide; overall filing in the tax filing guide

Frequently asked questions

Do foreigners working in Thailand pay personal income tax?

Yes. If you have Thai-source income — from employment, services or business earned in Thailand — it's in principle taxable there, regardless of tax residency. If employed, your employer usually withholds monthly from wages (PND.1), and you also file an annual return (employment income only commonly uses PND.91) to reconcile. Separately, if you stay 183 days in a tax year and become a tax resident, foreign income remitted into Thailand may also be taxable. To stay compliant, get a TIN, file honestly and use all lawful deductions; exact rates and rules follow current Revenue Department regulations.

How long until I'm a tax resident, and what does it change?

Staying a cumulative 183 days in a tax year (calendar Jan–Dec) makes you a tax resident. Two main effects: Thai-source income is taxable in Thailand either way; and as a resident, foreign income you remit into Thailand may also be taxed — an area that has tightened recently, so how "remittance" is assessed and any exemptions follow the year's rules. Residency doesn't change that "Thai income is taxable," but it affects the treatment of foreign income. Anyone planning a long stay with overseas income should plan ahead, subject to current Revenue Department rules; consult an accountant.

Can I get overpaid tax back, and how?

Yes. If the tax withheld by your employer or prepaid over the year exceeds your actual liability, the annual return computes the overpayment and you can claim a refund. Common refundable cases include mid-year resignation, allowances and deductions not fully counted in withholding, or actual income below the withholding estimate. The key is to list all eligible deductions honestly and completely in the return (self/spouse/children, social security, qualifying insurance/provident funds, home-loan interest, etc.) — this both lawfully lowers tax and recovers overpayments. Refund timing follows the Revenue Department; if unsure about documents, get an accountant's help.

Need help?

Taihubang advises on and assists with personal income tax in Thailand: assessing your liability and tax-residency status, mapping available deductions, obtaining a TIN, filing the annual PND.91/90, claiming overpayment refunds, and handling foreign-income issues. We don't arrange false filings; everything follows current Revenue Department rules, verified with licensed accountants. See our accounting & tax service or submit an enquiry; an adviser replies within 24 hours.