Sleep is a necessary component of a healthy lifestyle. A lack of sleep is known to affect mood and stress, which can cause you to feel anxious or depressed. Sleep deprivation can also affect your physical health by increasing your risk of conditions such as obesity and diabetes.

The NHS reports that 1 in 3 of us suffer from a lack of sleep, with stress, technology, and work often blamed as to why. The only way to break this cycle is to 'catch up' on it. This is done over the weekend or via strategic naps throughout each day for most workers. However, in some particular lines of work, workers may be allowed to sleep on the job to offset their sleep deficit. This is most prevalent in the care industry, where employees can work irregular hours such as nights or are expected to be on-call.

As opposed to the norm of staying awake and working during your day shift, on-call workers can be asleep for parts or the majority of their shift. Hence, it can be confusing to determine whether the workers in these sectors are eligible to receive the National Minimum Wage or not. With the Royal Mencap Society v Tomlinson-Blake case in 2021 setting a new precedent, there seems to be some clarification.

Therefore, this article will explore the different types of on-call and night shifts, whether employees can sleep during their shift, and whether they are entitled to the National Minimum Wage for hours spent asleep. Let's jump in.

Government guidelines state on-call employees working sleep-in shifts are not entitled to the National Minimum Wage for being available, only for hours spent working and carrying out their duties. However, they may be entitled to be paid for hours spent not working if they are required to be at a location and are not permitted to sleep.

On-call employees who work wake-in shifts are entitled to the National Minimum Wage for their shift as they are expected to be working for the whole duration. However, they can sleep for short durations, such as during a break.

What is an 'on-call' employee?

Workers who are 'on-call' - also referred to as 'on standby' - are expected to be available for work outside of the usual working hours. For instance, a live-in carer can be on call 24 hours a day, seven days a week. Still, they may only work between eight to ten hours a day - the total hours they have spent carrying out their duties.

Sleep-in and wake-in shifts

There are generally two types of on-call shifts; 'sleep-ins' or 'wake-ins' - often called sleeping or waking shifts.

The employer may require the employee to stay at the workplace for sleep-in shifts. In that case, the employee would need to sleep there too. Sleep-ins are primarily common in hospitals and care work due to dealing with emergencies. An example of this is an overnight carer who is present simply for reassurance, or in the event of an incident.

However, employees working a wake-in shift will not go to sleep and must be awake and working for the majority of the time. Again, this shift is primarily typical in the care sector, such as hospitals and carers. For instance, a wake-in overnight carer would stay awake for all hours of the night to supervise or assist when needed.

Are on-call workers entitled to the National Minimum Wage for their whole shift?

The Supreme Court considered this question in the Royal Mencap Society v Tomlinson-Blake case.

Mrs Tomlinson-Blake was a care worker who provided care and support for two adults in their home. Her employer was obligated to have a worker present throughout the night. Therefore Mrs Tomlinson-Blake worked sleep-in shifts from 10 pm to 7 am and was paid a flat rate of £22.35, plus one hour's pay. Although she had to remain on the premises during her shift hours, the facts of her case are as follows:

  • She did not have any specific duties.
  • She was provided with a separate bedroom for sleeping; she was expected to get a good night's sleep as she may have to work a day shift the next day.
  • She had to keep a 'listening ear' during the night in case the adults she was caring for required support. Over 16 months, she was required to assist only about six times, and therefore the need to help was described as 'real but infrequent'.

The original Employment Tribunal (ET) ruling decided that she was considered 'working' during her sleep-in shift and was therefore eligible for the National Minimum Wage for her shift. However, the Employment Appeals Tribunal (EAT) overturned this decision in 2021.

Employment Appeals Tribunal decision

The EAT found Mrs Tomlinson-Blake was only entitled to the National Minimum Wage for the hours she was 'awake for the purposes of working'; meaning the hours she was either sleeping or awake but not working would not count towards her billable hours.

Does this decision apply to all sleep-in or on-call shifts?

It depends. What matters most is whether workers are 'working' during shift hours or whether they are 'available' - regardless of if the shift is labelled as sleep-in or on-call. This is determined on a case-by-case basis, and there may be cases that are considered borderline. Still, for sleep-in workers, the difference can be distinguished by the following:

  • Working - employees are expected to be working for most of their shift; even if there are short breaks in which the employee can be asleep, such as napping when not busy.
  • Available - employees are expected to be asleep for most - if not all - of the shift but can be woken up to carry out specific tasks and duties if required.

It should be noted that the EAT stressed the importance of the facts since these will vary; what is contracted between the employer and employee, what is happening in practice etc. But, there will be four main considerations to take into account:

  1. The employee's purpose - If the worker is regulated or contractually obligated by the employer to be present at a location, this could indicate that the worker is working simply by being present.
  2. Is the employee restricted? - The extent to which the employee is restricted when it comes to being present on-site and being at the employer's disposal. For instance, does the employee need to remain on the premises, or can they come and go? Being restricted may indicate that the worker is working.
  3. Degree of Responsibility - How much responsibility does the employee have, and what types of activities might they be required to perform? For example, in the event of a fire, are they just responsible for calling emergency services, or would they be needed to tackle the fire themselves. If they are required to undertake further actions themselves, this may indicate that the worker is working.
  4. The immediacy of the requirement to provide services - Not just the urgency with which a worker is required to act, it also has to do with the level of responsibility they have. The EAT used the example of an employee who must decide whether they should intervene and deal with the problems, compared to an employee woken by another staff member responsible for intervening.

Which hours should be included in the National Minimum Wage calculation?

Employees working wake-in shifts are expected to work for most of their shift. Therefore, they are eligible to receive the National Minimum Wage for the entirety of the work period - regardless of whether they are allowed to sleep in-between tasks.

As mentioned earlier, if the employee is 'available' but not working, and is required to be present at - or near to - the workplace with the expectation that they will be ready to work immediately, then all hours should be included.

However, there is a condition to that rule; they will not be paid the National Minimum Wage for the entirety of their shift if one of the following applies:

  • The worker is at home: If the worker is at home and only needs to be 'available', for instance, to respond to an emergency, then only the hours that they are working would qualify - regardless if they were awake or asleep for the duration of their on-call shift.
  • The worker is sleeping or is allowed to sleep: If the worker is asleep at, or near, the workplace and sleeping arrangements have been provided by the employer, then only the hours where the employee is 'awake for the purposes of working' would qualify.
  • Live-in employee: A worker may not be entitled to the National Minimum Wage if they live in their employer's home and are treated as if they are part of the family. For instance, they are not paying for meals or accommodation and sharing chores or leisure activities with the family.


On-call employees are certainly eligible for the National Minimum Wage; however, this depends on if they satisfy specific criteria.

Government guidelines state that on-call employees working wake-in shifts are entitled to the National Minimum Wage for their entire shift. In comparison, on-call employees who work sleep-in shifts are entitled to the National Minimum Wage only for hours spent working. They may also be entitled to be paid for hours spent not working if they are unable to sleep during their shift, have not been provided sleeping facilities, and are required to be at a location.

Knowing this, it is far from black and white, with the government stating that these scenarios need to be reviewed on a case-by-case basis, factoring in all the facts of the case.