IFF Research said that the four-day working week model would see staff receive 100% of their pay while working 80% of the week.

The scheme was successfully trialled at IFF Research between June 2025 and March 2026, with regular pulse surveys and specified indicators used to track and measure wellbeing.

The company said that the trial saw a 30% fall in average sick leave per person and that the model included emphasising a collective sense of agency, with teams deciding how to adopt the four-day working week model to fit with their clients and projects.

The office therefore stays open five days a week, with some teams taking Friday off and others opting for Monday.

There are 256 other companies in the UK currently supporting a four-day week, according to the 4 Day Week Foundation.  

 IFF Research was created in 1965 and is an independent social research agency working with government, businesses and third sector organisations.

Jan Shury, chief executive at IFF Research, said: “From the outset, we knew the model could only work if it was done with people, not to them. The trial asked everyone to think differently about how we plan, prioritise and collaborate, and I’m incredibly proud of the way the team embraced that challenge.

“People really leaned into the spirit of the experiment, finding practical ways to work smarter and ensure we continued to deliver well and on time. It’s what’s allowed us to continue.”