How to Use the Bonus & Overtime Tax Calculator

This free 2026/27 calculator shows the true cost of extra PAYE earnings in the UK — a bonus, overtime, or simply the next £1 of salary. It splits Income Tax, employee National Insurance, student loan repayments and (optionally) the High Income Child Benefit Charge, for England, Wales, Northern Ireland and Scotland.

Step-by-Step Guide

1. Set your tax position

Tax nation: choose Scotland if you are a Scottish taxpayer (tax code usually starts with S). Everyone else uses the rest-of-UK bands.
Pay frequency: enter current pay as annual, monthly, four-weekly, fortnightly or weekly. The calculator annualises it for the tax year.
Tax code: 1257L is the 2026/27 default (£12,570 allowance). S1257L is the Scottish default. BR, D0, D1, 0T, NT and K codes are also read.
Current gross pay: expected earnings this tax year before the extra bonus or overtime you are testing.

2. Add the extra earnings

One-off: a bonus or a single overtime payment in 2026/27.
Recurring: overtime you expect every pay period; it is multiplied by your pay frequency to get an annual figure.

3. Layer pension, loans and Child Benefit

Salary sacrifice: extra pay is reduced before Income Tax, employee NI and student loan.
Relief at source: pension reduces Income Tax (and adjusted net income) only; NI and student loan still use cash pay.
Student loans: Plan 1, 2, 4 or 5 at 9%, plus an optional postgraduate loan at 6%. Both can apply at once.
Children: if you claim Child Benefit, set the number of children to include the HICBC taper from £60,000 to £80,000.
State Pension age: tick this to turn employee NI off.

4. Read the results

Results update as you type. The highlighted figure is how many pence of the next £1 you keep. The table applies the same rules to your extra lump, including any band crossings (for example a bonus that pushes you through £50,270 or into the £100,000 personal-allowance taper).

Formula: kept = extra − Δtax − ΔNI − Δloan − ΔHICBC

Common Scenarios & Examples

Scenario: £1,000 bonus on a £45,000 salary

Goal: see the next-pound rate and how much of a modest bonus survives PAYE in England.

Nation: England, Wales & NI. Tax code 1257L. Annual pay £45,000.
One-off extra £1,000. No pension, no student loan, no Child Benefit.

What you should see

Next £1: 20p Income Tax + 8p NI = 28p deducted, 72p kept
£1,000 bonus: about £200 tax + £80 NI = £720 kept

Both the current salary and the bonus sit inside the basic-rate band and the main NI band.

Scenario: Overtime that crosses £50,270

Goal: see a mixed rate when extra pay straddles the higher-rate / upper-earnings-limit threshold.

Annual pay £48,000, one-off extra £5,000, rest of UK, no loan.
The first £2,270 of the extra is still basic rate + 8% NI; the remainder is higher rate + 2% NI.

Approximate result

You keep about £3,218 of the £5,000 (roughly 36% deducted). The “next £1” figure at £48,000 stays 28% because that pound is still in the basic band.

Scenario: The 60% trap plus student loans

Goal: see why a bonus above £100,000 can feel far more expensive than 40%.

Annual pay £100,000, extra £2,000, rest of UK, Plan 2 + postgraduate loan.
Between £100,000 and £125,140 the personal allowance is withdrawn (£1 lost per £2 earned), adding 20 percentage points of Income Tax.

Next £1 at £100,000

Income Tax 60p + NI 2p + Plan 2 9p + postgraduate 6p = 77p deducted, 23p kept.

In Scotland the same taper sits on the 45% advanced rate, so Income Tax alone is 67.5p before NI and loans.

2026/27 rates used

Rest of UK: 20% to £50,270, 40% to £125,140, 45% above. Personal allowance £12,570, tapered from £100,000.
Scotland: 19% / 20% / 21% / 42% / 45% / 48% with published 2026/27 thresholds (starter to £16,537, basic to £29,526, intermediate to £43,662, higher to £75,000, advanced to £125,140).
Employee NI: 8% between £12,570 and £50,270, then 2%. Nil over State Pension age.
Student loans: Plan 1 £26,900, Plan 2 £29,385, Plan 4 £33,795, Plan 5 £25,000 (all 9%); postgraduate £21,000 at 6%.
Child Benefit / HICBC: £27.05 a week for the first child and £17.90 for each other child; 1% of the annual benefit clawed back per £200 of adjusted net income from £60,000 to £80,000.

Disclaimer & Limitations

Not professional advice: this is an educational estimate for the 2026/27 tax year (6 April 2026 to 5 April 2027). It is not tax, payroll or financial advice. Confirm figures with a qualified adviser or your payroll team before making decisions.

Assumptions: standard Category A employee NI; extra amounts treated as PAYE earnings of the same tax year; pension percentage applies to current pay plus extra; salary sacrifice reduces the Income Tax, NI and student-loan bases; relief at source reduces Income Tax and adjusted net income only. Tax codes BR, D0, D1, 0T, NT and K are supported in simplified form. W1/M1 (non-cumulative) suffixes are ignored — the engine uses an annual year-end view, not a single bonus-month PAYE estimate.

Not modelled: employer NI, Marriage Allowance beyond M/N letters already in the code, Blind Person’s Allowance, benefits in kind, tax-free childcare, Scottish/UK savings and dividend rates, self-employment, or mid-year tax-code changes. A large bonus paid in one month can look harsher on that payslip than the annual figures here; PAYE usually unwinds over the rest of the year.

Bug Reports and Suggested Improvements

Please email suggestions and bug reports to: bonusovertimetaxcalc@personalfinances.me, thank you.

Bonus & Overtime Tax Calculator UK 2026/27

📋 Your pay this tax year

📊 Results

📈 Marginal rate by income

📅 Breakdown