How to legally ensure compliance with UK employment law when transitioning to a four-day work week?

11 June 2024

The four-day work week is an emerging trend in the business world. It offers potential benefits such as increased productivity, improved employee morale, and striking a better work-life balance. However, transitioning to a four-day work week can be a complex process. It involves not only redefining work schedules but also ensuring compliance with UK employment law.

Given this context, it's crucial for businesses to understand how to approach this transition legally and ethically. This article will provide you with comprehensive guidance on ensuring your business is compliant with UK employment law during this transition. Let's delve into the details.

Understanding the Legal Framework

Before making any changes to your employees' work schedules, it's crucial to gain a thorough understanding of the laws that govern work hours and conditions.

UK employment law is wide-ranging, covering aspects such as maximum working hours, paid leave, and rights of part-time workers. The Working Time Regulations 1998 (WTR) is critical for our discussion. It outlines the rules for working hours, including breaks, maximum work week hours, and night shifts.

It's important to note that the WTR stipulates a maximum 48-hour working week, averaged over a 17-week period. However, an employee can choose to opt-out of this rule, provided it's in writing. This can be a crucial factor when considering a four-day work week, as the daily working hours may need to be extended to ensure the same weekly hours are maintained.

In addition to the WTR, the Employment Rights Act 1996 is another significant aspect of the UK's employment legislation. It outlines the rights of employees in terms of unfair dismissal and redundancy, which can be relevant if the shift to a four-day week leads to layoffs.

Redefining Working Hours and Shifts

After understanding the legal framework, the next step is to redefine your employees' working hours and shifts within the legal boundaries.

Remember, the shift to a four-day work week doesn't necessarily imply a reduction in working hours. It means redistributing the standard 35-40 hours over four days instead of five. For instance, instead of working eight hours a day for five days, employees might work ten hours a day for four days.

While doing so, ensure to abide by the WTR's directives on rest breaks — a 20-minute break for every six hours of work and an 11-hour rest period between work days. You must also adhere to the regulations on night work if the extended working hours fall into this category.

Managing Employee Contracts and Agreements

The transition to a four-day work week will also require alterations in employment contracts and agreements.

You need to arrange consultations with your employees or their representatives to discuss the changes. It's critical to maintain transparency and communicate the reasons for the shift, its benefits, and its potential impacts. You must also provide sufficient notice before implementing the changes.

If employees agree to the changes, you can update the contracts accordingly. If they do not, you might need to dismiss and rehire them on new contracts, but this should be a last resort due to its potential legal implications.

Adapting the Leave Policy

A four-day work week can complicate leave policies, so you'll need to adapt them accordingly.

Under the Working Time Regulations, full-time employees are entitled to a minimum of 5.6 weeks of paid holiday leave per year. With a five-day work week, this translates to 28 days. However, with a four-day work week, 5.6 weeks of leave would equate to 22.4 days.

To address this, you can consider each 'week' of leave as four days instead of five, thereby maintaining the 28-day entitlement. Alternatively, you can adjust the annual leave to 22.4 days, but this should be clearly communicated to employees.

Considering Part-Time Workers

Finally, it's vital to consider the impact of these changes on part-time workers.

Under UK law, part-time employees have a right to the same treatment as full-time employees. Therefore, if you're adopting a four-day work week for full-time staff, you should consider how to adapt part-time schedules to ensure they retain equivalent benefits.

This might involve adjusting part-time hours to align with the new full-time schedules, or redistributing part-time hours over fewer days. It's essential to discuss these changes with part-time employees and to update their contracts accordingly.

Ensuring Compliance with Health and Safety Regulations

In the process of transitioning to a four-day work week, businesses must not overlook the importance of complying with health and safety regulations. The Health and Safety at Work Act 1974 requires employers to ensure the welfare of employees at work. Prolonged working hours, as might be the case in a four-day working week model, could potentially have implications for employee health and wellbeing.

For instance, working for extended periods might result in increased stress levels, fatigue, or even musculoskeletal disorders, particularly for desk-based workers. Therefore, employers should conduct a comprehensive health and safety risk assessment to identify and mitigate potential risks associated with the new working hours arrangement.

Employers should also consider implementing flexible working arrangements to allow employees to manage their long working days better. For instance, allowing employees to start later or finish earlier on certain days could help them manage their work-life balance more effectively.

In addition, employers should consider the number of consecutive days an employee is required to work. Working four consecutive 10-hour days could potentially be more taxing than working five 8-hour days with breaks in between. Therefore, the arrangement of the working week should be carefully considered to promote the health and safety of employees.

Aligning the New Working Week with Intellectual Property (IP) and Data Protection Laws

Lastly, the transition to a four-day work week may have implications for intellectual property rights and data protection, particularly in the era of remote working and digital collaboration.

For instance, if a four-day work week results in more employees working remotely or at unusual hours, businesses must ensure that they have robust data protection measures in place. This is to prevent any potential data breaches or violations of the General Data Protection Regulation (GDPR).

As far as intellectual property is concerned, employers should ensure that their IP policies are up to date and clearly address the new working arrangements. Employees should be reminded of their obligations to protect company IP, even when working outside of the traditional working hours or from home.

Furthermore, businesses should ensure that they have appropriate IT support in place to support their employees during their working hours. This might mean adjusting the hours of the IT support team or hiring additional staff to ensure that support is available during the extended working hours.


Transitioning to a four-day work week is a significant shift that requires careful planning and execution to ensure compliance with UK employment law. From understanding the legal framework to adapting leave policies and considering health and safety implications, businesses must take a holistic approach to this transition.

Remember, the shift to a four-day week is not just about reducing the number of working days; it's about redefining work and offering employees the ability to achieve a better work-life balance. Therefore, while ensuring legal compliance, businesses should also focus on the potential benefits of this transition, such as improved productivity, enhanced employee morale, and better retention rates.

Ultimately, the success of the transition will depend on careful planning, effective communication, and ongoing review and adaptation. By taking these steps, businesses can ensure that they not only comply with the law but also create a work environment that supports the wellbeing and productivity of their employees.