Two answers for one bonus: how much your employer withholds in the payout month under TER, and how much tax the bonus genuinely adds once the year is recalculated.
Indonesia does not have a separate bonus tax rate. A bonus is simply part of your annual taxable income, so it is taxed at your marginal Pasal 17 rate — 5%, 15%, 25%, 30% or 35% depending on where it lands.
What confuses people is the payslip. Under the TER system the bonus is added to that month's salary and the whole month is taxed at the TER rate for the combined total. A Rp40 million bonus on a Rp20 million salary puts the month at about Rp60.6 million gross, which uses a TER rate of 20% on everything — so the withholding looks enormous. December then recalculates the year and gives back the excess by withholding less.
TK/0 employee, Rp20,000,000 monthly wage, Rp40,000,000 bonus in March, THR of Rp20,000,000 in another month:
Run your own numbers in the calculator — the split between brackets depends on your salary and status.
Because the year is always settled in December, the month a bonus is paid makes no difference to your annual tax. It only changes cash flow. What does matter is the tax year: a bonus paid in January 2027 for 2026 performance is 2027 income.
Assumes you work for the same employer all year. Changing jobs mid-year means each employer withholds separately and the true-up happens on your annual SPT. Verify with DJP.