Tempted by the four-day working week trial for your business?

One story which received a great deal of media coverage earlier this year was the publication of the results of a six-month trial involving around 2,900 workers who had moved to a four-day working week. The organisers of the UK trial heralded it as a success, and maybe you have been wondering if this could work for your business?

‘It is important to point out that this was not a trial led by the Government, nor did it investigate compressed hours where employees work their usual weekly hours over four days,’ says Lydia Wawiye, a solicitor in the employment team with Parfitt Cresswell.

The trial was organised by campaigners and researchers, who offer consulting to companies who wish to implement a four-day working week. The experiment was based on the 100-80-100 model; workers receive 100% pay for working 80% of their previous hours and commit to maintaining 100% productivity.

The models

There were 61 organisations which volunteered to take part and while some organisations closed one day a week, participating employers adopted different models. Organisations that needed to maintain five-day coverage used staggered days off, or employees ‘buddied up’ with a colleague with similar skills and covered each other’s day off.

Businesses with strong seasonal demand opted for annualised hours. Others adopted a ‘decentralised’ approach, allowing each department to work out the best model for its needs. Others made continuation of the scheme for specific divisions of the business conditional on that division meeting its key performance indicators (KPIs).

The results

After the trial ended, 92% of the organisations continued with the arrangement, many to assess its impact over a longer period. By publication of the report, 18 had adopted it permanently. This outcome needs to be considered in the context that the participating organisations were self-selecting volunteers who received support to implement the change in their business.

Positive impact

The report on the trial notes an improvement in employee wellbeing with 39% of employees saying that they felt less stressed at the end of the trial and 71% reporting reduced levels of burnout. They also reported significant decreases in employees leaving and absence rates.

Only 23 of the participating organisations provided data on changes to revenue, reporting an average 1.4% increase in productivity over the six-month trial period.


This may not be a realistic option for many businesses, for example it may not be affordable to recruit more staff or pay more overtime, which increases the wage bill to facilitate the time off. Businesses who need to ensure continual cover may have particular difficulty, particularly once absences due to annual leave and sickness are taken into account. Managing the working hours and sufficient cover, as well as monitoring performance or other KPIs, is likely to use up management time and create administrative challenges. For example, the trial did not consider customer satisfaction.

These arrangements may not achieve one of the desired outcomes of improved employee wellbeing, in fact they could have the opposite effect for some people. Although the principle is that employees will work more efficiently, for instance by jettisoning unnecessary meetings, those with intense workloads may struggle to get everything done in reduced hours.

Some employers may find that the four-day week works in some parts of the organisation but not others. This presents a difficult decision in weighing up the benefits in some parts of the business against the likely overall damage to morale and cohesion among the workforce.

Legal implications

There are a number of legal issues to consider when introducing the four-day week, whether as a trial or permanently.

Contractual changes

Contracts of employment will need to allow for the new working arrangements. Flexibility clauses may allow the employer to make the changes, but these still need to be brought about in a reasonable way. If there is no flexibility in the contract, employers need to agree changes to working hours and patterns with the employees. Some employers may need to introduce a requirement for employees to work shifts or work overtime to provide cover for colleagues. Employers need to factor in the time and resources to consult with staff to seek their agreement. Changing working hours and patterns could affect childcare arrangements or arrangements staff have in place to help accommodate a disability. Care needs to be taken when introducing changes to address individual circumstances. Failure to do so could be discriminatory.

Employers looking to run a trial should make it clear to employees that this is just a temporary measure. You will need to ensure that the contractual changes give you the option to change back to the previous working hours at the end of the trial.

Part-time workers

Part-time workers are protected from less favourable treatment compared to full-time employees. To ensure that they are fairly treated, options are available such as reducing their hours pro rata or increasing their pay. Otherwise you could risk an employment tribunal claim.

Double jobbing

Faced with the cost-of-living crisis, some employees may use their day off to take on a second job. This could lead to fatigue, particularly if the pace of their main job has increased since the four day-week was introduced, which could potentially reduce the individual’s productivity. In some settings, such as healthcare and construction, tiredness can present a danger to the health and safety of the worker and others. When checking for compliance with the rules on working time and rest breaks, employers must take into account work done with other employers.

We can check if your contracts address this situation and discuss how to introduce provisions to, at the very least, require employees to tell you about a second job. For some roles, the contract should address conflicts of interest and confidentiality issues that could arise.


Employers may wish to reduce the total number of days annual holiday allowance to reflect the reduced number of working days. This contractual change needs to be agreed as part of the package of changes. Where employees work different days of the week, such as on a staggered arrangement, we can work through with you how to take account of public holidays.

How we can help

If you are considering piloting a four-day week or restructuring your working arrangements, we can help you to evaluate the different options for your business.

Once you have selected a model, we can help you to work through the implications of the new arrangements and a trial to ensure fairness for all staff, providing clarity and a smooth transition, as well as giving you the option to reverse the decision.

To speak with one of our Employment Law lawyers and take advantage of our FREE initial consultation by calling us on 0800 999 4437 or clicking here.

This article is for general information only and does not constitute legal or professional advice. Please note that the law may have changed since this article was published.

Free Consultation

Book a free initial consultation with one of our legal experts

Book now

Find Your Nearest Office

Enter your postcode in the box below to find your closest office.

Newsletter Signup

Our FREE monthly newsletter will keep you up to date with the latest changes to law and also offers lots of great advice and articles.

Call us today on 0800 999 4437

Call Now