Unions are very clear that the answer should definitely be yes. Your hourly pay should average the National Minimum Wage whenever you are working, and you are clearly working when you are on an overnight shift at a service user’s home, even if you spend some of that time sleeping. In reality, overnight careworkers are often the only person at work on the shift. Looking after vulnerable children and adults, they have to deal with challenging demands at a moment’s notice. It is not as if they are free to come and go as they please.
Unfortunately, the law does not necessarily agree. In a much-criticised ruling in the case of Royal Mencap Society v Tomlinson-Blake  EWCA Civ 1641, the Court of Appeal has said that the “essence” of a careworker’s sleep-in shift is that they are expected to be asleep, only providing help when required. This means that while this ruling stands, most overnight careworkers on a sleep-in shift will only qualify for the National Minimum Wage when they are “awake for the purpose of working”.
UNISON, the union that brought the case, says this ruling challenges common sense, as well as the established legal understanding of what counts as work.
There will be an appeal against this ruling in the Supreme Court in 2020. In the meantime, the best way to resist cuts to overnight shift payments in the light of this ruling is to join a union and organise.