Employer costs and payroll basics in the UK
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The salary in a job advert is not the total cost of employing someone. An employer may also owe employer National Insurance, workplace pension contributions and other costs. Payroll calculates what the employee receives, reports the deductions to HMRC and accounts for employer liabilities.
This guide is an overview of costs and process, not a substitute for employer payroll software or compliance advice. Rates and thresholds for 2026/27 are published in official employer guidance and should be checked before preparing a real payroll.
Distinguish employee and employer amounts
Employee gross salary is the starting point for the worker’s payslip. PAYE Income Tax, employee National Insurance and relevant pension or student loan deductions affect net pay. Employer National Insurance is normally on top of gross pay; it is not a second employee deduction. A worker’s tax code, NI category and the employer’s eligibility for relief can all affect the figures. A budgeting exercise should document these assumptions so someone checking the numbers later knows what was included. The same gross salary can therefore correspond to a higher employment cost for the business.
The applicable employer NI category and rate depend on the worker and circumstances. Reliefs such as the Employment Allowance have eligibility rules and cannot be assumed for every employer. A budget that applies the headline rate indiscriminately can overstate or understate cost. Use the employer-cost view of the payroll calculator and verify the current official rules.
Account for workplace pensions
Automatic enrolment may require an employer to enrol eligible staff into a qualifying workplace pension and contribute. Eligibility depends on age, earnings and employment status, and workers can have rights to opt in even when not automatically enrolled. The minimum contribution basis may use qualifying earnings rather than every pound of gross salary.
Employee and employer contributions are separate cash flows. A pension contribution from the employer is an employer cost; a contribution withheld from the employee reduces the employee’s cash pay according to its particular tax treatment. Salary sacrifice is another arrangement with its own contractual implications. Check the pension scheme documentation before interpreting a payslip line.
Run and report payroll
An employer needs the worker’s details, tax code, NI category and pay information for the period. PAYE calculates withholding; the employer gives a payslip and reports pay and deductions to HMRC through Real Time Information in the required manner. A starter or leaver can change the data used in the calculation.
A payslip normally records gross pay, deductions and net pay. Year-to-date figures make later corrections visible. If a tax code is wrong, changing the employee’s salary in a spreadsheet is not the remedy; follow official payroll and tax-code processes. Keep payroll records for the required period and pay liabilities by the applicable deadline.
Build a realistic budget
Employer NI and pensions are not the only additional costs. Paid leave, sick pay, training, recruitment, equipment and benefits may matter. Not every cost is a statutory payroll charge, and some depend on the contract and the nature of the role. A calculator estimates the amounts included in its inputs, not every expense of hiring.
When comparing a contractor’s invoice with an employee salary, consider employment status and the different obligations, rather than just subtracting one headline number from the other. Ask your payroll provider or adviser to confirm which costs apply to your organisation. A careful estimate keeps employee net pay separate from the total employer budget.
Worked example: two perspectives on pay
Assume an employee earns £3,000 gross in a month. In a hypothetical payroll, the employee has £450 of combined tax and employee NI plus £100 of cash pension deduction, so net pay is £2,450. Suppose separately that the employer owes £300 of employer NI and makes a £90 pension contribution.
On these illustrative figures, the employer’s salary-plus-these-two-costs budget is £3,000 + £300 + £90 = £3,390, before other costs. The £300 and £90 are example amounts, not published 2026/27 charges. Employee net pay of £2,450 and employer budget of £3,390 answer different questions.
Frequently asked questions
Is employer NI deducted from employees?
No. It is generally an additional liability of the employer.
Does every employee have the same pension contribution basis?
No. Scheme rules and qualifying earnings can differ; check the scheme and automatic-enrolment guidance.
Does payroll software replace checking tax codes?
No. Employers still need accurate starter information and to apply updates through the correct process.
Official sources
Check the linked official guidance for the latest figures before making a decision.
Related calculators
UK Calculators is independent and not affiliated with or endorsed by HMRC or any UK government body. These examples are illustrative, not personal tax, financial or legal advice.
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