Guide to Checking Underpayment

You worked the full shift, covered that weekend when someone called in sick, stayed late because the team needed help, and perhaps you even came in earlier than usual; then payday arrives. You check your bank account expecting your usual salary, but something does not look right; the amount is lower than you expected, and you start wondering whether you calculated your hours incorrectly or whether payroll made a mistake.

If this has happened to you, do not simply shrug and move on. Payroll mistakes can happen, but repeated underpayment should not become something you quietly accept. Whether you are paid hourly, weekly, or monthly, your payslip and employment records give you an important way to check whether you have received what you are owed, and if you are a migrant who is still getting used to the UK workplace, understanding your pay is part of understanding your fundamental employment rights.

Start by Checking Your Payslip Line by Line

Your payslip is more than a document you glance at before payday; it records how your employer calculated your pay. UK employees and workers are generally entitled to receive a payslip on or before payday, showing your gross pay, deductions such as tax and National Insurance, and your net pay. If your pay varies according to the amount of time you work, your payslip should also clearly show the number of hours worked.

Compare the hours shown on your payslip with the hours you actually worked, checking your basic rate of pay, overtime, weekend or night rates if applicable, holiday pay, and any other payments you were expecting. Then look closely at the deductions. Tax and National Insurance are normal deductions, but you may also see pension contributions, student loan repayments, salary sacrifice arrangements, or other deductions permitted by law or your employment agreement. The aim isn’t to assume every deduction is wrong; it is to understand exactly why your pay differs from what you expected.

Know Which Pay Deductions Your Employer Can Make

This is where knowing your rights becomes particularly important, as an employer generally cannot simply decide to take money from your wages because they feel like it. Under UK employment law, deductions normally need to be required by law, authorised by your contract, agreed by you in writing beforehand, or fall within certain other legally recognised circumstances, such as recovering an earlier overpayment or complying with a court order.

There are also specific rules around deductions that could take your pay below the National Minimum Wage, with certain narrow exceptions. This is why you should not immediately conclude that an employer has acted unlawfully just because your take-home pay is lower than expected. First, identify what the deduction is and check your contract or written employment terms. For example, perhaps you forgot about a workplace pension contribution, agreed to a salary sacrifice arrangement, or received an earlier overpayment that your employer is now recovering. But if you cannot identify the reason for a deduction, that is when you should start asking questions.

Match Your Timesheets Against Your Actual Shifts

Sometimes the problem is not a deduction at all; your employer may simply have recorded fewer hours than you actually worked. This can happen surprisingly easily, particularly in workplaces where rotas change frequently, or workers pick up additional shifts.

Perhaps your manager asked you to cover Saturday, stayed two extra hours on Tuesday because a colleague did not show up, or called you in on your day off with a promise that the additional hours would be included in your next pay. Do not rely solely on memory; go back through your rota, timesheets, clock-in records, and messages from your manager or colleagues. If you have WhatsApp messages confirming that you were asked to cover a shift, keep them; if your workplace uses an electronic clock-in system, check those records where you have access.

Keep copies of your employment contract, rotas, payslips, timesheets, and relevant messages somewhere safe. Your records become particularly useful if the underpayment issue happens repeatedly.

Then calculate the exact difference; for example, if you were paid for 150 hours but your records show that you worked 158 hours, you now have a specific figure to discuss with payroll, which is much stronger than simply saying your salary looks wrong.

Raise the Underpayment Before It Becomes a Bigger Problem

Once you have checked the figures, speak to your employer, as there is nothing wrong with starting informally. In fact, Acas recommends raising unexpected deductions with your employer first, allowing them to explain or correct a mistake. You could contact payroll, HR, or your manager and explain exactly what you have found, showing them the calculation rather than approaching the conversation with accusations.

Something as simple as: “I have compared my payslip with my timesheet, and I believe eight hours from the weekend shift are missing; could you please check this?” gives them something concrete to investigate. However, do not keep everything verbal: if you have discussed the matter in person, follow up with an email confirming what was discussed, keeping the response you receive and any subsequent correspondence. If the issue is not resolved, you may be able to raise a formal grievance through your employer’s grievance procedure, and Acas recommends keeping written records throughout.

Do Not Miss the Acas and Employment Tribunal Deadlines

If your employer refuses to correct an underpayment or you cannot resolve the dispute internally, you may have legal options through Acas and, where appropriate, an employment tribunal.

For many unlawful deduction from wages claims, the usual tribunal deadline is 3 months minus 1 day from the date of the deduction, though where there have been multiple linked deductions, the rules can allow a claim relating to earlier deductions under specific conditions. This is critical because having an ongoing internal grievance does not automatically stop the tribunal clock, and Acas specifically advises that you should notify Acas within the relevant time limit even if you are still going through an internal grievance process.

Acas Early Conciliation can help you and your employer try to resolve the dispute before a tribunal claim, and if you eventually need to make a tribunal claim, you will usually need an Early Conciliation certificate first. Because employment disputes can become complicated, particularly where your contract, minimum wage, immigration status, or termination of employment is involved, consider getting appropriate employment advice rather than relying on social media explanations.

Being a Migrant Does Not Mean You Should Accept Underpayment

There can be an uncomfortable feeling that comes with being new to the UK: you may be thinking about your visa, grateful to have found a job, or worried that complaining about your pay will make your employer see you as difficult or put your position at risk. But being a migrant does not mean you should stop paying attention to your employment rights, as all workers have protection against unlawful deductions from wages and are entitled to the National Minimum Wage.

Your immigration situation may affect other aspects of your employment, so you should always make sure you understand the conditions attached to your particular visa, but that should not stop you from checking whether your employer has paid you correctly. Do not let the phrase “it is only £50” convince you that it is not worth checking, because while one missing payment might be a genuine payroll error, repeated missing payments are a different matter that can add up to hundreds of pounds over several months.

Your payslip deserves the same attention you give your bank statement: compare your hours, check your rate, understand your deductions, keep your records, ask questions when something does not add up, and put important conversations in writing. If you discover an underpayment, deal with it promptly rather than hoping it will correct itself next month. You worked for that money, and you are fully entitled to understand where it went and ask for what you are owed, so do not ignore the numbers.