From opening its first UK chocolate factory in Slough in 1932 to producing WHISKAS® in Melton Mowbray, Mars has invested more than £661 million across its UK operations since 2021. This investment is helping modernize British manufacturing, introduce new technology, improve efficiency and develop skilled careers.
Across the UK, millions of households enjoy Mars products every day. Whether feeding their pets WHISKAS® or PEDIGREE®, preparing a meal with Ben’s Original™ or Dolmio®, or enjoying M&M’S®, GALAXY®, and SNICKERS®, Mars brands have become part of everyday life. Behind these familiar brands are a network of UK factories, research facilities and skilled teams.
Mars has been manufacturing in the UK for more than 90 years. Since 2021, the company has invested over £661 million across its Petcare, Snacking and Food & Nutrition businesses. This investment is helping to modernize factories, introduce advanced technology, reduce energy use and create opportunities for people to develop new skills.
Here is how Mars is investing in its UK manufacturing sites and the people that work there.
MARS IN THE UK: KEY FACTS
- More than £661 million invested in UK operations since 2021
- £190 million investment in Slough to modernize chocolate manufacturing between 2023 and 2028.
- £161 million investment in Melton Mowbray to modernize pet food production by 2031.
- Four key manufacturing locations: Slough (Snacking), Melton Mowbray (Pet Nutrition), King’s Lynn (Food & Nutrition), Birstall (Pet Care products)
- Scientific Research: Waltham Petcare Science Institute in Leicestershire
- More than 10,000 Mars Associates working across UK manufacturing, veterinary health commercial and corporate operations.
- 97% of apprentices who complete their programs move into permanent roles at Mars.
How Is Mars investing £190 million in its Slough chocolate factory?
Mars began manufacturing in the UK in 1932, when Forrest Mars Sr. established operations on the Slough Trading Estate in Berkshire to produce the first MARS® bar. Today, Slough remains one of the UK’s largest confectionery manufacturing sites, producing well-known brands including MARS®, GALAXY®, MALTESERS®, and SNICKERS®.
Mars is investing £190 million between 2023 and 2028 to modernize the factory, introduce new technology and support chocolate production for years to come.
The program includes £32 million scheduled for 2027 and 2028, building on more than £118 million invested across Mars UK Petcare, Snacking and Food & Nutrition operations during 2024 and 2025.
The investment focuses on five key areas:
- Smarter manufacturing: Introducing digital twin technology and automated sensors to monitor chocolate production in real time. This helps teams control temperatures, mixing and packaging speeds, maintain a consistent quality and reduce ingredient waste.
- Modernizing Production Lines: Upgrading manufacturing equipment and automated packaging systems to improve reliability and efficiency.
- Improving energy efficiency: Updating cooling systems, steam generation and other factory equipment to reduce the energy needed to produce chocolate.
- Supporting UK and European Markets: The slough factory supplies UK retailers and exports chocolate across Europe. In 2025, it exported more than 12.3 million kilograms of chocolate to the Netherlands and over 2.7 million kilograms to Ireland.
- Developing workforce skills: More than 1,850 Associates work across the Slough site, including manufacturing, technical development and the UK head office. The investment also supports training in automation and digital maintenance.
This investment reflects our confidence in the UK as a hub to manufacture and innovate. Our Slough factory is deeply rooted in our heritage, and as a proud family-owned business, we are committed to investing in a future that creates lasting, positive impact for the communities where we operate.
How is Mars modernizing its Melton Mowbray pet food factory?
Mars has been producing pet food in Melton Mowbray, Leicestershire, since 1951.The factory is where WHISKAS® canned cat food and PEDIGREE® dog food were first introduced to British pet owners.
The UK is the world’s third-largest pet food market, with approximately 12.5 million cats and 13.9 million dogs. Mars products reach 9.7 million cats and 8.8 million dogs across the country, with WHISKAS® feeding 6.6 million cats.
To support this demand and prepare for the future, Mars is investing £161 million to modernize the Melton Mowbray factory by 2031. The investment includes:
- More recyclable packaging: Installing advanced production lines that will enable a switch to fully recyclable mono-PP pouches
- Modernizing factory operations: Upgrading equipment, site logistics and automated handling systems to improve production efficiency.
- Reduce manufacturing waste: Introducing smart optical sorting technology designed to cut production waste by 50%.
- Supplying UK and European customers: Around 95% of products made in Melton Mowbray are supplied to UK households, with the remaining 5% exported to European markets.
- Creating jobs and training opportunities: The project will create more than 30 employment opportunities and increase the number of permanent apprentice positions on site.
"The UK is a cornerstone of our global pet care business at Mars, and this £161 million investment is a direct statement of our confidence in the UK market and the vital role our British factories play within our wider European network. Melton Mowbray has been feeding the nation's pets for 75 years."
Where else does Mars manufacture products in the UK?
Where else does Mars manufacture products in the UK?
Alongside its major factories in Slough and Melton Mowbray, Mars operates specialist manufacturing facilities in King’s Lynn and Birstall.
King’s Lynn, Norfolk: Producing Ben’s Original and Dolmio
For more than 60 years, the King’s Lynn factory has produced products including Ben’s Original™ and Dolmio®. Investment at the site has focused on improving rice pouch production, automating sauce preparation and upgrading equipment. The factory also has a sedum roof, industrial wastewater treatment facilities and solar power installations to help reduce its environmental impact.
Birstall, West Yorkshire: Making pet treats and care products
The Birstall factory specializes in pet treats and care products including Schmackos™ and PEDIGREE® care treats.
A £1.2 million investment has upgraded manufacturing and packaging equipment, helping the factory improve efficiency and meet demand for pet wellness, training and dental care products.
How does Mars use science to improve pet nutrition?
Manufacturing at Mars is supported by scientific research, including work carried out at the Waltham Petcare Science Institute near Melton Mowbray.
For more than 60 years, Waltham has researched companion animal nutrition, health and wellbeing.
Its teams of veterinary scientists, animal nutritionists and behavior specialists study areas including pet nutrition the microbiome and animal behavior. This research helps inform the development of Mars Petcare products, including their recipes, nutritional standards and quality controls, globally.
How is Mars investing in UK jobs and skills?
Alongside modernizing its factories, Mars is investing in the people and skills needed for the future of British manufacturing. Training programs across UK sites help Associates develop expertise in engineering, digital technology, manufacturing and supply chains.
Key initiatives include:
- Apprenticeships: Since 2024, Mars has supported more than 160 apprentices across engineering, operations, digital systems and supply chain functions.
- Long term careers: Across the UK business, 97% of apprentices who complete their program are offered permanent roles at Mars.
- Digital Skills Training: The Mars Data Academy helps existing Associates develop skills in data analysis, digital manufacturing tools and predictive maintenance, using funding through the UK Apprenticeship Levy.
- Supporting young people: Mars works with local schools and education providers to offer practical work experience into manufacturing, supporting wider UK efforts to reduce the number of young people not in employment, education or training (NEET).
