Thai Personal Income Tax: A Simple Overview

Welcome back to “Tax in 10 Minutes.” This episode introduces Thai personal income tax, how it is calculated, and ways to plan. Tax rules, deduction amounts, and eligibility may change. The figures below are translated from the source lesson and must be checked against the Revenue Department’s current guidance before use.

What is personal income tax?

Personal income tax is tax paid to the government on income received during a tax year, including salary, wages, and other income. The source notes that tax revenue contributes to government services and national development.

Tax refunds and additional payments

A refund or additional payment reflects the difference between the tax calculated for the year and tax already withheld. If the final amount is lower than the amount withheld, a refund may be due; if it is higher, additional tax may be payable. A refund does not by itself mean that total tax was low, and an additional payment does not by itself mean it was high. The final liability is based on taxable income and applicable rules.

Withholding tax

Withholding tax is deducted by an employer or payer from income during the year and remitted to the Revenue Department in advance, so the full amount is not necessarily paid at year-end.

Two calculation approaches described in the lesson

1. Calculate tax on net taxable income

1. Add assessable income received during the tax year, such as salary, wages, bonuses, and interest.
2. Subtract expenses allowed for each income category, such as expenses under Section 40(1) for salary.
3. Subtract eligible allowances, which may include personal, child, parent, and insurance allowances.
4. The remaining amount is net taxable income.
5. Apply the progressive tax rates that apply to the relevant tax year.

What is net taxable income?

It is assessable income after the expenses and allowances allowed by law have been deducted.

Progressive tax example in the source

The lesson lists these example brackets: THB 0–150,000, exempt; THB 150,001–300,000, 5%; and THB 300,001–500,000, 10%, followed by an ellipsis. These are not a complete or current tax table.

For an example net taxable income of THB 400,000, the source calculates THB 0 tax on the first THB 150,000, THB 7,500 on the next THB 150,000 at 5%, and THB 10,000 on the remaining THB 100,000 at 10%, for a total of THB 17,500. This example reproduces the lesson and has not been revalidated against current law.

2. Alternative calculation at 0.5% in some cases

The lesson describes a second method that multiplies total assessable income by 0.5% under certain legal conditions. Its example refers to employment income only and assessable income not exceeding THB 120,000. Eligibility and thresholds are date-sensitive; confirm them with current official guidance before calculating tax.

Tax planning topics

Eight categories of income

The lesson refers to eight income categories under Section 40 of Thailand’s Revenue Code:

1. Income from employment, including salary and wages.
2. Income from duties, positions, or services, including fees and commissions.
3. Goodwill, copyright royalties, or other rights.
4. Interest and dividends.
5. Income from renting property.
6. Income from independent professions.
7. Contract income where the contractor invests in materials or equipment.
8. Other income, including online sales as described by the source.

The tax treatment and allowable expenses differ by category. Confirm the classification of your income under current rules.

Expenses and allowances

Allowable expenses vary by income type. The source gives salary expenses of 50%, capped at THB 100,000. It also lists these example allowances: personal allowance THB 60,000; spouse allowance THB 60,000 when the spouse has no income; child allowance THB 30,000 per legally recognized child; parent allowance THB 30,000 per parent aged 60 or older who meets an income condition; life and health insurance premiums; home-loan interest; donations; and purchases of mutual fund units such as RMF or SSF. Amounts, fund rules, and eligibility are subject to change.

Donations

The lesson says donations may generally be deductible up to the amount paid, subject to a limit of 10% of income after expenses and other allowances. Check which donation and calculation rules apply to the relevant year.

Planning for employees

• Check which personal, child, or parent allowances may apply.
• Review eligible deductions for your circumstances. The lesson mentions life or health insurance and mutual funds; do not buy a product solely for a tax benefit.
• Plan saving and investing with long-term goals in mind. The lesson mentions RMF and SSF funds as tax-related examples, but their rules can change.

Planning for a child

• Check eligibility for child allowances.
• Keep education-expense records if they are relevant under current rules.
• Plan for future education costs.

This article is a translation of a general lesson, not current tax advice. Verify all rates, thresholds, deductions, and filing conditions with Thailand’s Revenue Department or a qualified tax professional.