Thai Tax Deductions to Know Before You File

Automatic Expense Deduction & Personal Allowance

Employment income (Section 40(1)) qualifies for a 50% expense deduction, capped at ฿100,000, and every taxpayer automatically gets a further ฿60,000 personal allowance. Taxolase applies both of these automatically — you never need to enter them yourself.

Example: with ฿600,000 of salary and nothing else claimed, the expense deduction is ฿100,000 (50% would be ฿300,000, but the cap applies) and the personal allowance is ฿60,000. Taxable income is ฿440,000 and tax is ฿21,500, which puts you in the 10% bracket.

Family-Related Allowances

A spouse with no income of their own qualifies for a ฿60,000 allowance. Each child qualifies for ฿30,000 (the 2nd child onward, born in 2018 or later, qualifies for ฿60,000). Supporting a parent aged 60 or above adds a further ฿30,000 per parent.

Insurance & Retirement Funds

Life insurance premiums are deductible up to ฿100,000, and health insurance up to ฿25,000 (combined with life insurance, capped at ฿100,000). Provident fund and RMF contributions combined are deductible up to ฿500,000, capped at 30% of income — this is the single largest lever for anyone in a high tax bracket. Thai ESG funds have a separate ฿300,000 limit for purchases through the end of 2026.

Example: take the same ฿600,000 salary and add ฿100,000 of life insurance and ฿100,000 into an RMF. Deductions become ฿100,000 + ฿60,000 + ฿100,000 + ฿100,000 = ฿360,000, taxable income falls to ฿240,000, and tax falls from ฿21,500 to ฿4,500 — a saving of ฿17,000 for ฿200,000 spent on things you may have wanted anyway.

One change to know about: SSF purchases stopped qualifying for a deduction from 1 January 2025, so a new SSF purchase no longer lowers your tax.

Limits that catch people out

Most mistakes come from limits that apply on top of each deduction's own amount:

• The 30%-of-income rule: RMF, provident fund and Thai ESG are each also limited to 30% of your income, so a lower earner cannot use the full ฿500,000 or ฿300,000.
• Life and health insurance share one limit: health insurance is capped at ฿25,000 and the two together at ฿100,000.
• Provident fund contributions count toward the same limit as RMF, so add up everything before buying.
• Deductions cannot create a loss: if your deductions exceed your income, taxable income is zero, not negative, so an extra deduction has no value once you owe no tax.

Taxolase caps each deduction at its own limit and applies the 30% rule, but it does not enforce the combined insurance limit or the donation ceiling, so enter only the amounts you are entitled to.

Charitable Donations

General donations are deductible up to 10% of income after other deductions and allowances. Some categories of donation may qualify for a larger deduction, subject to conditions set by the Revenue Department, so check the current rules for the specific recipient before you give.

Working out your own tax

Enter your income, then your deductions in Step 2, and the calculator shows your taxable income, tax and marginal rate. On the Advisory step it estimates how much more an RMF or Thai ESG purchase would save at your income. For filing dates and forms, check the Revenue Department, since deadlines can change from year to year.