Why it looks like more tax
Weekly and monthly payroll treat each period as a fraction of the year. A busy week pushes more pay into the basic band for that week, and NI is charged per period. Over a full tax year, cumulative coding generally evens this out.
Example
Jake earns £28,000 and does 10 extra hours a week at time and a half on a £14.36 rate. That's £215 a week, or about £11,200 a year extra. He keeps around 72p in every pound, roughly £8,060.
Compare the reward with the hours
Extra gross pay is not the full cash reward for extra work. Compare the additional net amount and the time required, keeping ordinary contracted pay separate from the extra shift.
Try it with your own numbers
Calculate how much of your overtime pay you keep after tax and NI.
Frequently asked questions
Does overtime count towards my pension?
It depends on your scheme. Many auto-enrolment schemes use 'qualifying earnings', which includes overtime.
Check it on GOV.UK: Tax on your private pension (opens GOV.UK in a new tab)
Sources
Tax year 2026/27. Check these official sources for current rules and deadlines.
Related calculators
- Overtime Tax Calculator — Calculate how much of your overtime pay you keep after tax and NI.
Related guides
- How Bonuses Are Taxed — How UK bonuses are taxed through PAYE, why the payslip looks heavy, and how sacrificing a bonus into a pension works.
- How PAYE Tax Works — A plain-English explanation of PAYE: how employers deduct tax, what cumulative coding means, and why your payslip changes month to month.