The NMW is based on basic pay

A worker’s basic pay must comply with the NMW. That basic pay can then be used to produce an “enhanced” rate for different shifts, for example, “time-and-a-half”. However, the enhanced rate cannot be used as a basis for working out whether the NMW is being paid, even if a worker never receives only basic pay and always receives the enhanced rate.

For example, in Hamilton House Medical Ltd v Hillier [2009] UKEAT/0246/09, Ms Hillier worked as a care worker. Her basic pay rate was below the NMW but she was paid “time-and-a-third” for weekday nights and “time-and-two-thirds” for weekend nights. As she almost always worked nights, her average hourly pay was above the NMW. Even so, as her basic rate of pay was below the NMW, the regulations had been breached.