National Minimum Wage and unsociable hours

Night work is a reality for many industries. From healthcare to hospitality, security to logistics, unsociable hours are often the backbone of our most essential services. And yet, for HR professionals and managers, night work also brings compliance challenges – particularly around the National Minimum Wage (NMW).

Employers who get it wrong risk not only reputational damage but also costly legal claims. This informative blog post will provide an in-depth look at the rules, the pitfalls, and the landmark case that continues to shape how employers should approach unsociable hours.

What are the rules?

The starting point is simple: all workers, regardless of when they work, must be paid at least the National Minimum Wage. This applies whether the employee is working during the day, overnight, or during unsociable hours. The rate depends on the worker’s age and status (for example, whether they are an apprentice), but rates were increased across the board in April 2025.

Crucially, however, there is no legal requirement to pay workers more simply because their shift falls at night. Enhanced pay for unsociable hours is only mandatory if it has been agreed contractually or is set out in a workplace policy. Many employers choose to offer higher pay for night work to attract and retain staff, but the law only insists on the NMW floor.

What counts as paid working time?

For night workers, employers must make sure that all relevant hours are counted towards NMW compliance. Paid working time includes the following:

• Active working time: Hours spent performing duties during the night 

• Training: If training happens during night hours, it must be paid at or above NMW 

• Additional duties: Activities like cleaning, stock checks, or security rounds carried out during night shifts

Where things tend to get a bit more complicated is with sleep-in shifts. These are common in sectors like care and residential services. Here, the question of what counts as working time is a subject that has even been tested in the highest courts, which we will be exploring shortly.

Sleep-in shifts explained

The dividing line for sleep-in shifts is whether the worker is awake for the purposes of working.

• Sleep-in carers who are given proper sleeping facilities are only entitled to NMW when they are awake and performing duties. 

• Night workers expected to remain active for most of the shift, even with some rest breaks, are generally entitled to NMW for the entire shift.

This principle was firmly cemented by the Supreme Court in the case of Royal Mencap Society v Tomlinson-Blake (2021), which clarified how sleep-in arrangements interact with the National Minimum Wage. Before looking at employer guidance, it’s worth examining the details of this pivotal case.

Royal Mencap Society v Tomlinson-Blake

The background

The Royal Mencap Society, a well-known charity providing care for vulnerable adults, employed Mrs Clare Tomlinson-Blake as a support worker. Alongside her regular shifts, she was required to complete sleep-in shifts from 10pm to 7am.

For these, she received a flat rate of £22.35 plus one hour’s pay, totalling £29.05. No specific tasks were allocated during these shifts, but she was expected to “keep a listening ear” and intervene if her clients needed help.

In practice, such interventions were rare – only six occasions in a 16-month period. When disturbed, she was entitled to further pay after the first hour. Her claim was that all hours spent sleeping in should count towards working time for the purpose of the National Minimum Wage.

The legal journey

• Employment Tribunal (ET): Initially upheld her claim, ruling that all hours of the sleep-in shift should be treated as working time 

• Employment Appeal Tribunal: Supported the ET’s decision 

• Court of Appeal: Reversed the decision, holding that Mrs Tomlinson-Blake was only entitled to NMW when awake and carrying out duties 

• Supreme Court: Confirmed the Court of Appeal’s judgment on 19 March 2021

The ruling made clear that being available for work, while asleep and not performing active duties, does not count as time worked for NMW purposes.

The Shannon Appeal

At the same time, the Court also heard the case of Mr Shannon, a night care assistant who lived in accommodation provided by the care home where he worked. He was expected to remain on-site from 10pm to 7am, free to sleep unless required to assist.

In return, he received accommodation and a modest weekly sum. His claim was that every night’s sleep should count as salaried hours, entitling him to nearly £240,000 in arrears.

Both the ET and the EAT dismissed his claim, and the Court of Appeal upheld those decisions. The Supreme Court confirmed that his sleep-in hours did not constitute working time for NMW purposes unless he was awake and performing tasks.

The outcome

The Supreme Court’s ruling provided long-awaited clarity. For HR professionals and managers, the key message is this: sleep-in shifts do not attract NMW for the hours a worker is asleep, unless the worker is awake and actively carrying out duties.

What this means for employers

The Mencap ruling has had an undeniable impact across sectors that rely on sleep-in shifts, particularly in care. Employers no longer face the risk of vast back-pay liabilities for historic sleep-in shifts. However, the case does not lessen the importance of ensuring compliance in other areas.

Employers must distinguish clearly between being available for work and actually working. They must also keep accurate records of when workers are called upon during sleep-in shifts. Moreover, they must make sure that pay rates, even for interrupted sleep, never fall below NMW once active work begins.

Failure to observe these principles risks not only financial penalties but also damage to workforce trust – particularly in sectors already struggling with recruitment.

Top tips for HR and managers

1. Audit for NMW compliance

Carry out regular reviews to make sure that all pay structures comply with National Minimum Wage. Pay careful attention to deductions for uniforms, meals, or accommodation, which could push pay below the legal minimum. Unsociable hours often involve extra costs for workers, so be especially mindful of these risks.

2. Clarify pay in contracts

Contracts should explicitly set out what pay workers will receive for night shifts, sleep-in duties, and other unsociable hours. Transparency reduces the risk of disputes and helps build trust.

3. Factor into holiday pay

Where staff regularly receive additional pay for night or unsociable hours, these amounts should be included in holiday pay calculations. Failing to do so risks breaching employment law.

4. Itemise payslips

Ensure payslips break down payments for night work and enhancements separately. This not only improves transparency but also provides clear evidence of compliance if challenged.

The challenge of unsociable hours

While the law does not mandate higher pay for unsociable hours, many employers choose to offer premiums. This serves both as recognition of the inconvenience to staff and as a recruitment and retention tool. However, offering premiums brings its own complexities – such as ensuring they are factored correctly into holiday pay and overtime rates.

Employers should also consider the broader impact of unsociable hours on staff wellbeing. Fatigue, work-life balance, and health risks are all heightened by regular night work. HR teams should balance compliance with proactive wellbeing initiatives, such as flexible scheduling, enhanced rest breaks, and health assessments for night workers.

Common pitfalls to avoid

• Assuming sleep-in hours always count as work: The Mencap ruling makes clear they do not, unless the worker is awake and performing duties 

• Overlooking deductions: Even lawful deductions can reduce pay below NMW if not monitored carefully 

• Ignoring holiday pay implications: Night shift premiums must usually be included when calculating holiday pay 

• Failing to document arrangements: Vague or inconsistent practices around unsociable hours increase the risk of disputes and claims

Practical steps for compliance

• Keep detailed records of hours worked, particularly during sleep-in shifts. 

• Regularly review pay policies to ensure they reflect current law and case law developments. 

• Train line managers on NMW compliance, especially those scheduling unsociable hours. 

• Engage with staff about the challenges of night work and address concerns proactively.

How can Sapphire HR support your business?

Juggling compliance with National Minimum Wage and unsociable hours can be incredibly challenging, especially with evolving case law like Royal Mencap Society v Tomlinson-Blake. At Sapphire HR, we work closely with organisations across sectors to ensure their policies, contracts, and pay structures are fully compliant.

Our team can audit your current arrangements, provide tailored advice on sleep-in shifts, and help you build clear, transparent policies that minimise risk. Beyond compliance, we support businesses in balancing legal obligations with employee wellbeing so that those working unsociable hours feel recognised and supported.

If you’d like specialist guidance on managing night work, sleep-in arrangements, or National Minimum Wage compliance, get in touch today. Together, we can help you stay compliant, protect your organisation, and create a fairer working environment for your people.