You open your payslip and find that your take-home pay is lower than expected. Among the lines is a deduction you do not recognise, or one that looks larger than it should be. Before you assume the worst, work through it in order. Some deductions are required by law, some are agreed with you, and some are not allowed at all. This guide shows how to tell the difference and what to do next.

Start with what is required by law

Certain deductions are compulsory: PAYE, NSSF, SHIF and the Housing Levy. Check them first. The PAYE calculator, the SHIF calculator, the housing levy calculator and the NSSF calculator show what each should be for your salary. If your payslip differs, it may be a payroll error. Read your payslip line by line explains what every line means, and how to spot mistakes on your payslip lists the usual errors.

Next, deductions you agreed to

Some deductions come from agreements you signed: a loan or salary advance repayment, a sacco contribution, a union fee or a voluntary pension contribution. Look at the papers you signed. The amount and the duration should match. A salary advance should end when it is repaid; see employer loans and salary advances: tax treatment. If a deduction carries on after the debt is cleared, ask for it to stop and for a refund.

Deductions that are not allowed

An employer cannot deduct whatever it likes. Deductions for uniforms, breakages, shortages or fines are restricted, and generally need to be provided for in the law or agreed in a lawful way. Deducting pay as a penalty or taking a large share of pay for a mistake can be unlawful. If a deduction falls in this category, you can challenge it. Check your contract, which should say what may be deducted; see what to check in an employment contract before you sign.

Check that the arithmetic works

Compare your gross pay, the deductions and the net pay. Add up the deductions yourself. If your gross pay changed, for example because of overtime or an allowance, the statutory deductions will also change. The net to gross salary calculator works backwards from your take-home pay to the gross pay it implies, which helps you confirm whether the numbers are consistent.

Ask for an explanation in writing

If you cannot explain a deduction, ask payroll or HR in writing. Quote the month, the line on the payslip and the amount, and ask three things: what the deduction is for, what the legal or contractual basis is and when it will end. A written request creates a record, and a calm tone gets better results than an angry one. Give a reasonable time to reply, for example five working days.

Keep your evidence

Save the payslips for the months in question, your contract and any messages. Compare several months to see when the deduction began. Keep a simple note of dates. Tax records checklist and document log is a handy way to keep everything together. If the matter reaches a labour officer, a clean file will help.

If the deduction was an error

Payroll mistakes happen. Ask for the amount to be refunded in the next payroll, with the correction shown on the payslip. Check afterwards that the refund arrived, and that the statutory contributions were also adjusted, since a wrong gross pay affects them as well.

If the employer will not explain or refund

Escalate to a senior manager in writing, and then to the labour office in your county if there is no resolution. A trade union or legal aid clinic can also help. Do not stop work or take the money back yourself; follow the process, because actions outside it can weaken your position.

Check the other side too

Tax deductions should be paid over to KRA. If you suspect PAYE is deducted but not remitted, read when your employer does not remit your PAYE, and compare your P9 with iTax. Also confirm your NSSF, SHIF and Housing Levy are being paid with how to check your NSSF, SHIF and Housing Levy are being paid.

Prevent surprises

Review each payslip when it arrives, not months later. A quick look at gross pay, deductions and net pay takes two minutes. The earlier a mistake is found, the easier it is to fix.