Piece workers (‘output’ work)
[ch 4: page 111]Workers (including homeworkers) paid according to the pieces of work or tasks they do (piece workers) have the right to a minimum fair piece rate of 120% of the NMW (regulation 43, NMWR 15). There are strict rules governing the information employers must give to workers about how the fair piece work rate is calculated for each task. This includes details of the “mean hourly output rate” per piece or task (the number of pieces or tasks an average worker can complete in an hour). If the notice does not contain all required information, the employer must pay the NMW for every hour worked. Guidance on calculating the NMW for output-based piece workers can be found on the GOV.UK website.
UK government, Minimum wage for different types of work - paid per task or piece of work done (https://www.gov.uk/minimum-wage-different-types-work/paid-per-task-or-piece-of-work-done)