Underpayment of wages

Getting the facts straight first

Before treating this as a legal wrong, work out exactly what has gone wrong and why. The two problems you describe are different in law:

Being paid for the wrong number of hours usually means you have not received wages you were entitled to. If you worked the hours and your contract or agreed rate covers them, the shortfall is money owed to you.

Being paid at the wrong hourly rate could mean either that you were paid less than the rate you agreed with the employer, or that you were paid less than the legal minimum. These attract different remedies.

Many payroll errors are just that, errors, rather than deliberate wrongdoing. A missed shift on a timesheet, a rota not being submitted, a rate not updated after a birthday or an anniversary, or a delay in a rate change taking effect are common and innocent explanations. That matters because the sensible first step is almost always to raise it and give the employer the chance to correct it, not to assume bad faith.

Your minimum legal rights on pay

If you are a worker or employee, you are legally entitled to at least the National Minimum Wage or National Living Wage for every hour you work. The rate depends on your age (and whether you are an apprentice). From April 2025 the rates are broadly 12.21 pounds per hour for those aged 21 and over, 10.00 pounds for 18 to 20 year olds, and 7.55 pounds for those under 18 and apprentices. Even if you agreed a lower rate, that agreement cannot lawfully undercut the minimum wage. Student status does not remove this right; there is no special lower minimum wage just because you are a student.

Separately, whatever rate you agreed with your employer (if higher than the minimum) is a contractual entitlement. Failing to pay it, or paying for fewer hours than you worked, is normally an unlawful deduction from wages under Part II of the Employment Rights Act 1996, and can also be a breach of contract.

Gather your evidence

Before raising it formally, collect what shows what you were actually owed. Useful items include:

1. Your contract or written statement of terms, which should set out your rate of pay.
2. Your payslips, which by law you are entitled to receive.
3. Any record of the hours you worked, such as rota screenshots, clock-in records, timesheets, or your own diary or messages arranging shifts.
4. Any messages confirming your agreed hourly rate or a rate increase.

Then work out the difference between what you were paid and what you should have been paid, hour by hour if necessary.

Raise it informally first

The quickest and least stressful route is usually to point the error out to your manager or payroll. Explain clearly which pay period is affected, how many hours you worked, the rate you should have been paid, and the shortfall. Ask for it to be corrected in the next pay run or by a supplementary payment. Keep it in writing (email or message) so there is a record. Most genuine errors are fixed at this stage.

If that does not work, raise a formal grievance

If informal contact does not resolve it, put in a written grievance following any grievance procedure in your contract or staff handbook. Set out the facts, attach your evidence, state the amount you are owed, and ask for payment by a specific date.

Escalation routes if you are still not paid

There are two main external routes, and they are not mutually exclusive.

For a National Minimum Wage underpayment, you can report your employer to HMRC, which enforces the minimum wage. You can complain online through GOV.UK or via the Acas helpline. HMRC can investigate, order the employer to pay arrears, and impose penalties. This route is free and does not require you to bring a tribunal claim yourself.

For any shortfall in wages you were entitled to (whether below the minimum wage or simply below your agreed rate, or for unpaid hours), you can bring a claim to an employment tribunal for unlawful deduction from wages. If you have left the job, you may also be able to claim breach of contract.

Before making a tribunal claim you must first notify Acas and go through Early Conciliation, which is a free process where Acas tries to help you and the employer reach agreement without a hearing. You start this through the Acas website or helpline.

Time limits, which matter a great deal

The time limits are strict. For an unlawful deduction from wages claim you normally have three months minus one day from the date of the deduction, meaning from the date you should have been paid the correct amount. If there have been several underpayments, the clock runs from the most recent one, and you can generally claim back up to two years of linked deductions where there is less than three months between them or they arise from the same error.

Starting Acas Early Conciliation pauses this clock, so if you are approaching the deadline, contact Acas promptly rather than waiting. Do not let the three month period slip, because tribunals only rarely extend it.

Cost, risk and practical strategy

Employment tribunal claims do not have a fee, but they take time and effort. For a modest pay shortfall, the informal route and, if needed, the HMRC minimum wage route are usually more proportionate than litigation. Keep everything in writing, be precise about the figures, and be reasonable in tone, because a clear and accurate account of hours and rates is your strongest asset and often prompts a swift correction.

What would change the answer

Some facts could affect your position. If you are genuinely self-employed rather than a worker, the unlawful deduction rules do not apply and you would be looking at a contractual debt claim instead, though most casual student staff are workers or employees. If part of the shortfall reflects a lawful deduction, for example tax, National Insurance, or a deduction your contract clearly authorises, that is not unlawful. And if the dispute is really about whether you actually worked the hours you claim, the tribunal would focus on the evidence of hours worked, which is why good records matter.

If you tell me your age, your agreed hourly rate, how many hours are in dispute, and whether you are still employed there, I can be more specific about the amounts and the best route for your situation.