Bonus tax calculator 2026/27
Estimate the extra Income Tax, employee National Insurance and student-loan deductions created by adding a cash bonus to your annual salary.
What the estimate is comparing
Income Tax is the annual difference between salary alone and salary plus bonus. Employee NI and student-loan amounts are the extra deductions created when the whole bonus is added to one selected pay period. The remainder is labelled an estimated eventual after-tax value.
This is not a bonus-payslip forecast. Exact PAYE needs the tax code, payment date, cumulative taxable pay, tax already deducted and any week-1/month-1 operation. A large one-off payment can therefore look different on the payment date even when the annual tax position later settles.
Why the percentage kept can change
A bonus sits on top of other income. It can cross an Income Tax band, enter a student-loan threshold or push adjusted net income above £100,000, where the Personal Allowance starts to taper. NI also changes from 8% to 2% above the upper earnings limit.
Questions people ask
Is a bonus taxed at a special rate?
No separate Income Tax rate applies merely because pay is called a bonus. It is employment income added to other taxable pay, although payroll timing can make the payslip deduction look unusual.
Does a bonus trigger student-loan deductions?
It can. Payroll tests earnings against the threshold for that pay period, so a bonus can create or increase a deduction in the month or week it is paid.
Can salary sacrifice change the result?
Potentially. If an employer permits bonus sacrifice before entitlement arises, pension treatment may change taxable and NI-able pay. Scheme rules and timing matter; use the salary sacrifice calculator only as a separate planning scenario.
Official sources
- GOV.UK: Income Tax rates and allowances
- HMRC: employer rates and thresholds for 2026/27
- HMRC: further guide to PAYE and National Insurance
For a fuller explanation of payroll timing, read how bonuses are taxed in the UK.