Employers may be entitled to restitution of overpayments owing to a mistake of fact, but not a mistake of law.

There was dispute about when a person should be regarded as working for the purposes of calculating the minimum wage.

In deciding when a worker is working for the purposes of the NMW Regulations, an ET should look at the nature of the work; the extent to which the worker’s activities are restricted when not performing the particular task; the mutual obligations of the parties (although the way in which remuneration is calculated is not conclusive); and the extent to which the period during which work is being performed is readily ascertainable.

It was claimed that there had been no unauthorised deduction because a bonus was described as discretionary.

The word ‘wages’ includes discretionary bonus payments where the employee has been told that he or she will receive the payments.

A female cook compared her basic hourly pay with that of three men: a joiner, a painter, and a thermal insulation engineer.

She won her equal pay case, despite her overall job package being better than the one the males had. The Lords held that each individual contractual term had to be compared, not the overall wage for the job.

The NHS recruited male prosthetists from private practice; the men worked alongside female prosthetists who were already working for the NHS. The men retained the salary which they had earned in private practice, which was more than the women earned.

The House of Lords held that the NHS’s pay protection policy constituted a material factor defence to an equal pay claim within what is now the Equality Act 2010. They had proved that they had the defence because they had (what is now termed) a ‘proportionate means of achieving a legitimate aim’. The aim was to bring more prosthetists in to the NHS and paying the new staff more than the old was, on the facts, a proportionate means of doing so.