Why Does My Take-Home Pay Change?

Your take-home pay is calculated each pay period based on your earnings in that specific period. This means that changes to your income, deductions, or tax situation can cause your net pay to vary.

Common reasons your take-home pay changes

Bonuses or commission

When you receive a bonus or commission payment, it's added to your regular salary in that pay period. Bonuses are taxed at your marginal rate (the highest rate of tax you pay), which can make your tax appear higher that month. This is normal – the bonus is taxed at the rate that applies to your total income for the year.

Overtime hours

If you work overtime, your gross pay increases for that period. Overtime is subject to income tax and National Insurance just like your regular salary. If the overtime pushes you into a higher tax band, you'll pay tax at that higher rate on the overtime portion, which can affect your take-home pay for that month.

Tax code changes

If your tax code changes, your take-home pay will adjust. This can happen if HMRC updates your code due to changes in your circumstances, benefits in kind, or to collect underpaid tax from previous years. You should receive a notice from HMRC explaining any tax code changes.

Pension contribution adjustments

If you change your pension contribution percentage, or if your employer adjusts pension deductions, this will affect your take-home pay. Increasing your pension contributions reduces your taxable income, which can actually increase your take-home pay in some cases (especially with salary sacrifice arrangements).

Student loan repayments

If you have a student loan and your earnings cross the repayment threshold mid-year, you'll start seeing student loan deductions in your pay. This reduces your take-home pay, but it's a normal deduction if you have a student loan.

Number of pay periods

If you're paid weekly or fortnightly, the number of pay periods in a calendar month can vary. Some months have five pay days instead of four, which can make your monthly take-home pay appear higher or lower depending on how the dates fall.

Seasonal work patterns

If your hours vary seasonally (for example, more hours in summer, fewer in winter), your take-home pay will reflect these changes. More hours mean more gross pay, but also potentially more tax if it pushes you into a higher band.

What you can do

If your take-home pay changes unexpectedly, check your payslip to see what's different. Look at your gross pay, each deduction, and compare it to previous payslips. Most changes are normal and expected based on your earnings and circumstances.

Use our salary calculator to estimate what your take-home pay should be based on your current income and deductions. This helps you understand whether the changes you're seeing are normal or if something needs to be corrected.

If you're concerned about a specific change, check your tax code first – an incorrect code can cause unexpected variations. You can check your tax code on your payslip or through your personal tax account on GOV.UK.

Related guides

For more information about UK tax and how take-home pay is calculated, see our UK Tax Guide. If your take-home pay seems lower than expected, read our guide on why your take-home pay might be so low.