Thai Bonus Withholding Tax Calculator

Calculate the withholding tax in the month you receive a bonus using the Revenue Department method, from your salary, bonus and the allowances notified to your employer, plus the bonus left after tax.

Under the PND 1 instructions, the employer annualises salary (× 12), deducts the 50% expense allowance up to THB 100,000 and the notified allowances, and applies the progressive rates; yearly tax ÷ 12 is the monthly withholding. For a bonus, the bonus × times paid per year is added to yearly salary, tax is recalculated, and the salary-only tax is subtracted to give the bonus tax. That plus the month's salary tax is withheld in the bonus month.

Revenue Department example: THB 70,000 salary, THB 200,000 bonus and THB 370,000 allowances. Yearly pay with bonus is THB 1,040,000; after the THB 100,000 expense deduction and allowances, THB 570,000 is taxed at THB 38,000. Salary alone is taxed THB 14,500, so the bonus tax is THB 23,500; adding that month's THB 1,208.33 gives THB 24,708.33 withheld.

Withholding is a prepayment. Your real tax is settled in the annual return from actual yearly income and allowances; overpayments are refunded and shortfalls paid. Provident fund exemptions above THB 10,000, income from other payers and mid-year salary changes are not modelled.