Thailand Tax Filing Guide

the tax filing requirements and the deadlines in Thailand for 2026. The guide covers: the annual PIT return (PND 90/91) — filed between January 1 and March 31 each year; the corporate CIT half-year return — filed within 2 months of the end of the first half of the accounting period (by August); the VAT monthly return (P.P.30) — filed by the 15th of the following month; the e-filing system via the RD Smart Tax Application; and the withholding tax returns (PND 3/53).

Annual PIT Return (PND 90/91) — แบบแสดงรายการภาษีเงินได้บุคคลธรรมดา

Filing period — January 1 to March 31: The personal income tax (PIT) return for the preceding tax year (the calendar year) must be filed between January 1 and March 31 of the following year. For the 2025 tax year (the income earned in 2025), the return must be filed by March 31, 2026.
PND 90 vs PND 91: The PND 90 (แบบ ภ.ง.ด. 90) is used by the taxpayers with the income from the employment and the other sources (the business, the rent, the professional fees, the capital gains, etc.). The PND 91 (แบบ ภ.ง.ด. 91) is used by the taxpayers with only the employment income (the salary, the wages, the bonuses) where the employer has deducted the withholding tax at source.
Tax payable: The tax payable is calculated at the progressive rates of 0% to 35% after the deductions and the allowances. The excess tax withheld by the employer is refundable. The tax must be paid by the filing deadline (March 31).

Corporate CIT Half-Year Return (PND 50) — ภาษีเงินได้นิติบุคคลครึ่งปี

Filing deadline — within 2 months of the half-year end (August): The company must file the half-year corporate income tax (CIT) return (แบบ ภ.ง.ด. 50) within 2 months of the end of the first half of the accounting period. For the company with the January-December accounting period, the half-year return must be filed by the end of August.
Tax payment: The half-year CIT is paid based on the estimated profit for the full year (the "tax on the estimated net profit"). The company may pay 50% of the estimated full-year tax or pay based on the actual profit for the first half. The overpayment is credited against the annual CIT.
Annual CIT return (PND 50): The annual CIT return must be filed within 150 days of the fiscal year-end. The CIT rate is 20% of the net profit. The small companies (the paid-up capital not exceeding THB 5 million and the revenue not exceeding THB 30 million) pay at the progressive rates of 15% to 20%.

VAT Monthly Return (P.P.30) — ภาษีมูลค่าเพิ่ม

Filing deadline — 15th of the following month: The VAT-registered business must file the monthly VAT return (แบบ ภ.พ. 30) by the 15th day of the following month. For example, the VAT return for January must be filed by February 15.
VAT rate — 7%: The standard VAT rate in Thailand is 7% (the temporary rate, extended annually). The output VAT (the VAT charged to the customers) minus the input VAT (the VAT paid on the purchases) = the net VAT payable or refundable.
Zero-rated and exempt supplies: The exports and the international services are zero-rated (0% VAT). The certain supplies (the basic food, the medical services, the education, the financial services) are exempt from the VAT.

E-Filing — RD Smart Tax Application

The Revenue Department provides the RD Smart Tax application and the online portal (the "e-Filing" system at https://efiling.rd.go.th) for the electronic filing of the PIT, the CIT, the VAT, and the WHT returns. The e-filing is mandatory for the juristic persons (the companies) and is available for the individuals. The e-filing deadline for the PIT is extended to April 8 if the taxpayer files electronically and pays via the e-payment system (the "e-Payment" extension).

Withholding Tax Returns (PND 3/53)

PND 3 (แบบ ภ.ง.ด. 3): The monthly withholding tax return for the withholding tax deducted from the employment income (the "WHT on the salary"). The employer must file PND 3 by the 7th of the following month and remit the tax withheld.
PND 53 (แบบ ภ.ง.ด. 53): The monthly withholding tax return for the withholding tax deducted from the payments to the juristic persons (the companies) — the dividends, the interest, the royalties, the rent, the service fees. The payer must file PND 53 by the 7th of the following month.
Annual summary (PND 1 Kor / PND 2 Kor): The employer must also file the annual summary of the withholding tax (PND 1 Kor — the "WHT certificate") to the employee by February of the following year, and the summary to the Revenue Department (PND 2 Kor) by March 31.

FAQs

Can I file the PIT return online?

Yes. The RD Smart Tax application and the e-Filing portal allow the online filing of the PIT return (PND 90/91). The online filing is available from January 1 to April 8 (extended from March 31) if the taxpayer pays the tax via the e-payment method.

What are the penalties for the late filing?

The late filing incurs the penalty of 1.5% per month (or fraction thereof) on the tax payable, up to the maximum of 40% of the tax. The additional surcharge (the "เงินเพิ่ม") is charged at 1.5% per month. The criminal penalties (the fine and/or the imprisonment) may apply in the case of the wilful evasion.