Bulk bonuses and bonus tax
Bulk bonus creates a bonus for many employees at once, calculated from a wage basis rather than typed in per person. It is how 13th month, performance bonuses and any company-wide payment get made without a spreadsheet.
Where: Payroll › the payroll run › Bulk bonus You need: payroll rights for that batch cycle
Before You Start
Decide the wage basis. This is the whole decision. The same "one month's pay" bonus produces materially different amounts depending on which wage it is a month of.
Decide who is in scope, including part-year employees. Proration and any minimum-service rule apply here.
Warn people about the tax. Bonus income lifts annual tax, and because KAMI withholds annually, that lands across the remaining periods of the year — not only in the bonus month.
The wage basis decides the amount
| Wage basis | Bonus calculated from |
|---|---|
| Basic Salary | The contractual basic salary |
| Basic Monthly Wage | The derived basic monthly wage |
| Fixed Monthly Wage | Basic plus fixed recurring allowances |
| Gross Monthly Wage | Basic plus other payments in the gross basis |
| Average Total Wage | An average of actual total wage |
| Fixed Amount | A flat figure, the same for everyone selected |
⚠️ For an employee with significant allowances, a gross basis can be substantially more than a basic one. This is a policy and compliance decision — confirm it against contracts and local rules before running it, and record what you decided and why.
Average Total Wage behaves differently from the rest: it reflects what people actually earned, so employees with heavy overtime receive more. That is either exactly what you want or a surprise, depending on the bonus's purpose.
How to create a bulk bonus
- Open the payroll run and go to Bulk bonus.
- Choose the wage basis and the multiplier or amount.
- Select the employees. Check the list rather than accepting the default scope.
- Create the bonus.
- Recalculate the affected payslips — the bonus is applied at calculation.
- Review a sample of resulting payslips, including a high earner and a part-year employee, before verifying.
Bonus tax
Bonus amounts are taxed on the bonus basis, which is a different treatment from regular income. Combined with annual withholding, this produces the effect people query most:
A bonus raises tax for the rest of the year, not just the month it is paid. The bonus increases estimated annual income, the annual tax rises, and each remaining period carries a share of the increase.
If your company reconciles tax across the year, later periods will also absorb any over- or under-withholding that the bonus introduced. See Payslip tax details explained.
What Happens Next
- The bonus appears on the payslip as an other payment with bonus tax treatment.
- Withholding changes for the remaining periods of the year.
- The bonus is included in that period's statutory and year-end reporting.
- Removing a bonus after calculation requires a recalculation to take effect.
Tips
- Run it against a handful of employees first, on a real run, and read the payslips. A wage-basis mistake applied to everyone is a very public error.
- Check the extremes. Look at your highest earner, your lowest, and someone who joined this year. If those three are right, the middle usually is.
- Send a note before payday explaining that withholding will rise for the rest of the year. It costs one message and prevents a queue of questions.
- Do not fix a bonus with a manual tax adjustment. If the tax looks wrong, understand why before overriding it — the annual mechanism is usually behaving correctly.
- Record the decision. Which basis, which multiplier, who was in scope, and who approved it. You will be asked next year.
Troubleshooting / FAQ
Q: The bonus is not on the payslips. Recalculate them. Bonuses apply at calculation.
Q: Two employees on the same salary got different bonuses. Check the wage basis. Anything other than basic salary picks up allowances or actual earnings, which differ between people.
Q: An employee's take-home fell in the month after the bonus. Withholding rose because annual estimated income rose. It is not a deduction from the bonus; it is the rest of the year adjusting.
Q: A part-year employee received less than expected. Proration, and possibly a minimum-service rule — see 13th month pay.
Q: Can we pay a bonus outside a payroll run? No. It attaches to a payslip, which is what makes it taxed and reported correctly.
Screenshots
These screenshots came from our previous help centre and may show an earlier version of the interface.
