There's no separate "overtime tax rate"
Overtime pay isn't taxed differently just because it's overtime. It's added to your other earnings for the period and taxed the same way as the rest of your pay, through the normal Income Tax and National Insurance rules.
Why overtime can still change how much is deducted
Overtime increases your total earnings for the period, and UK Income Tax is charged in bands. Each extra pound is taxed at the rate for the band it falls into. For the 2026/27 tax year, income above the Personal Allowance up to £50,270.00 is taxed at 20%, with the 40% higher rate applying above that. If overtime pushes part of your pay into a higher band, that portion, not your whole pay, is taxed at the higher rate.
National Insurance works in a similar band-based way on its own separate thresholds, so extra overtime pay can also mean extra National Insurance for that period.
A one-off high-earning period isn't the same as a pay rise
If overtime makes one payslip unusually high, PAYE may deduct more tax in that specific period than in a typical month or week. This is a feature of how PAYE spreads your Personal Allowance and tax bands across the year, not a penalty for working overtime. It can even out over the rest of the tax year depending on your later earnings. Whether that overtime counts towards a pension contribution depends on your employer's own scheme — this calculator treats overtime as not pensionable. See why your payslip can differ from a salary calculator if an overtime payslip looks different from an annual estimate.
See the effect on your own take-home pay
Because the actual effect depends on your existing salary, tax region, pension contributions and any student loan, there's no single figure that applies to everyone. The Overtime Calculator compares your take-home pay with and without a specific amount of overtime, using the same shared tax engine as WageOra's other calculators. See How WageOra Works for how it's calculated. This is an estimate, not personalised tax advice.