Minimum Wage Arrears Calculator
If your employer has underpaid you, enter your age band, what you were actually paid, your weekly hours, and how many weeks — the calculator works out exactly what they owe you.
Arrears Calculator
Calculate how much backpay you are owed if you were underpaid. Covers 2017 to 2026 historical rates.
HMRC can reclaim up to 6 years of arrears. Contact HMRC or ACAS if you believe you have been underpaid.
What happens next?
If the calculator shows you are owed money, you can report the underpayment to the Fair Work Agency confidentially via gov.uk. The Agency can require your employer to repay 200% of the arrears as a penalty. You can also bring a claim at an Employment Tribunal within 3 months of the last underpayment. See our NMW Violation Guide.
Important note on older underpayments
The calculator above uses the current April 2026 rate. If you were underpaid in a previous year, the minimum rate for that period was lower. The Fair Work Agency applies the rate that was in force at the time of underpayment. This calculator is a guide — for older cases use the historical rates table.