Rate of record
Am I being paid the minimum wage?
The diagnostic compares your effective hourly rate after deductions to the applicable NMW band, then totals the 6-year back-pay liability. Arrears recover at the current rate, not the historic rate.
Verdict
Which deductions count against NMW
A deduction reduces pay for NMW purposes if it is for the employer's own use or benefit: uniform, tools, training, till shortages, security checks, employer-provided accommodation above the daily offset cap. A deduction for the worker's own benefit (pension, union dues, season-ticket loan) does not reduce NMW pay. Tips and service charge do not count toward NMW pay at all and never have.
The six-year window and the current-rate quirk
HMRC can recover arrears for any pay reference period in the last six years. The arrears are calculated at the rate in force today, not the rate in force when the worker was underpaid. That can roughly double the cash recovery vs a naive historic-rate calculation. The diagnostic above applies the current rate to the historic weekly underpayment.
Report this to HMRC or the Fair Work Agency
Underpayment is enforceable. Workers can report anonymously and arrears are recovered at the current rate, not the historic rate.