Tax on Commission: How It Works, With Calculator

Employment commission is taxable pay, like salary. There is no separate flat commission Income Tax rate: the amount you pay depends on your total taxable income and the tax bands that apply to you. A commission payment can push part of your income into a higher band without changing your tax code.

The deduction on one commission payslip can look higher because of when the payment arrives and whether PAYE is cumulative or uses W1/M1 treatment. The annual example below separates the extra Income Tax from NI, pension and student-loan deductions. Use the take-home pay calculator to compare annual salary with and without commission; it does not reconstruct a one-off payroll deduction.

1. Enter your gross annual salary in the take-home pay calculator. Select your tax year, region, pension and student-loan settings.
2. Note the annual Income Tax and take-home pay, then add the gross commission you expect to receive in that tax year to your salary. Keep the other settings the same.
3. Subtract the first Income Tax result from the second to estimate the extra annual Income Tax. Compare annual take-home results separately to see the estimated effect of the other deductions.

Try the example: calculate £40,000 salary only, then calculate £40,000 salary plus £15,000 commission. These are editable annual estimates, not the exact deduction on a one-off commission payslip. NI and student-loan deductions depend on pay-period earnings; spreading a lump sum across an annual estimate can give a different result.

This is an annual Income Tax comparison for 2026/27, not a prediction of a particular month’s payslip. Assume England, Wales or Northern Ireland, the standard £12,570 Personal Allowance, one job, and no pension deductions, other income or tax reliefs.

The first £10,270 of that commission uses the remaining basic-rate band at 20% (£2,054). The other £4,730 is taxed at 40% (£1,892). So the whole commission is not taxed at 40%.

NI, student loans and pensions are separate deductions. The payment date, tax code and previous pay affect the actual commission payslip. Scottish employment-income bands are different.

Compare the £40,000 baseline with the £55,000 annual estimate, or personalise the £55,000 calculation.

First compare the code on both payslips. Moving into a higher tax band does not require a different tax code. Payroll can deduct more tax using the same code when your taxable pay increases.

If the code did change, sign in to HMRC’s Check your Income Tax service and read the explanation. An income change may affect your allowances or an adjustment to collect tax, but the timing alone does not tell you why HMRC changed it.

A one-off commission also does not, by itself, establish a second job or require an emergency code. If it was paid separately, ask payroll how the payments and tax were combined for the pay period.

With a cumulative code, payroll uses your actual taxable pay so far in the tax year, the tax-free pay and tax bands available up to that pay period, and the tax already deducted. The result determines the tax to deduct or repay now.

It does not simply calculate tax on a predicted full-year salary and multiply that bill by the fraction of the year elapsed. A large commission can make this month’s deduction unusually high; later periods can adjust the total as more allowances and bands become available.

With W1, M1, X or NONCUM, payroll instead calculates tax for the current pay period without using earlier pay and tax to reconcile it. See cumulative vs M1/W1 tax for the difference, or the commission emergency-tax checklist for what to check next.

Estimate your taxable pay for the whole tax year, 6 April to 5 April: pay already received plus the remaining salary and commission you reasonably expect. Do not multiply an unusually high commission month by 12, and do not omit commission you have already received.

Compare that with the estimate in your HMRC account. Check previous employments, pensions and company benefits too. Update inaccurate details rather than assuming every code change after commission is caused by the commission.

If an adjustment collects tax you owe, read which year and amount it relates to. A reduced allowance can have several causes; it does not automatically mean an underpayment. HMRC’s coding explanation is the place to check.

The Personal Allowance falls by £1 for every £2 of adjusted net income above £100,000, reaching zero at £125,140. Commission can take you into this range.

For example, £105,000 adjusted net income leaves a £10,070 allowance. In England, Wales and Northern Ireland, the £5,000 above £100,000 creates £2,000 of higher-rate tax plus £1,000 from the lost allowance: £3,000 extra Income Tax. That is an effective marginal rate of 60% on that slice, not a statutory tax band. Scottish rates differ; NI and student loans are additional.

Adjusted net income includes more than salary and can be reduced by qualifying pension contributions and Gift Aid. A personal pension contribution and salary sacrifice are different arrangements; do not use a salary-sacrifice result as an exact SIPP calculation. See the tax cliffs map and HMRC’s adjusted-net-income guidance below.

• Payroll: commission amount, taxable pay, pay period, previous pay and tax carried forward, or whether the issued code was applied.
• HMRC: the code itself, estimated income, allowances and employment records. Use the tax-code correction service.

Have your latest two payslips, tax-code notice and any P45 ready. Ask payroll to explain the tax using the period number and year-to-date totals. Our payslip checker can help you review deductions, but a steady-pay estimate cannot establish the exact refund due on an irregular commission payment.

After HMRC issues a new code, check that it appears on a subsequent payslip. A refund depends on the tax actually overpaid and your circumstances; it is not guaranteed just because one deduction was large.