| MEP Badger Investments Ltd | Financial services | 2022 |
| Mepmg Ltd | Information & communication | 2018 |
| Meqsico Ltd | Professional & scientific | 2007 |
| Mequtee Ltd | Wholesale & retail | 2025 |
| Merak Consulting Limited | Professional & scientific | 2010 |
| Merak Events Limited | Arts & recreation | 2023 |
| Merbl Living Limited | Real estate | 2021 |
| Mercedes Services Ltd | Wholesale & retail | 2015 |
| Merch & Dice Transport Ltd | Transport & logistics | 2025 |
| Merch and REP Limited | Wholesale & retail | 2021 |
| Merchant Fabrics Limited | Wholesale & retail | 2007 |
| Merchants Hoard Ltd | Wholesale & retail | 2023 |
| Merchants Property Services Limited | Real estate | 2003 |
| Mercia Crematoria Developments Limited | Real estate | 2008 |
| Mercia Industries Ltd | Construction | 2022 |
| Mercia Power Limited | Financial services | 2019 |
| Mercia Power Response (Albion Close) Limited | Energy | 2016 |
| Mercia Power Response (Asher Lane 2) Limited | Energy | 2016 |
| Mercia Power Response (Beels Road) Limited | Energy | 2024 |
| Mercia Power Response (Bradberry Balk Lane Bess) Limited | Energy | 2024 |
| Mercia Power Response (Bradberry Balk Lane) Limited | Energy | 2019 |
| Mercia Power Response (Carlisle Road) Limited | Energy | 2019 |
| Mercia Power Response (Carlisle Street East) Limited | Energy | 2023 |
| Mercia Power Response (Chesterfield Road) Limited | Energy | 2016 |
| Mercia Power Response (Common Lane) Limited | Energy | 2016 |
| Mercia Power Response (Common Side Lane) Limited | Energy | 2019 |
| Mercia Power Response (Cuckoo Road) Limited | Energy | 2016 |
| Mercia Power Response (Fordbridge Lane) Limited | Energy | 2020 |
| Mercia Power Response (Fulwood Road) Limited | Energy | 2018 |
| Mercia Power Response (Geddington Road) Limited | Energy | 2019 |
| Mercia Power Response (Graphite Way) Limited | Energy | 2016 |
| Mercia Power Response (Greyfriars Way) Limited | Energy | 2022 |
| Mercia Power Response (Hallam Way) Limited | Energy | 2020 |
| Mercia Power Response (Hatton) Limited | Energy | 2020 |
| Mercia Power Response (High Street) Limited | Energy | 2022 |
| Mercia Power Response (High View Road) Limited | Energy | 2021 |
| Mercia Power Response (Hull Road) Limited | Energy | 2022 |
| Mercia Power Response (Manners Avenue 2) Limited | Energy | 2016 |
| Mercia Power Response (Mansfield Road) Limited | Energy | 2020 |
| Mercia Power Response (Nottingham Road) Limited | Energy | 2016 |
| Mercia Power Response (Outgang Lane) Limited | Energy | 2016 |
| Mercia Power Response (Petre Street) Limited | Energy | 2022 |
| Mercia Power Response (Pontefract Road) Limited | Energy | 2016 |
| Mercia Power Response (Private Road NO.5) Limited | Energy | 2016 |
| Mercia Power Response (Riby Street) Limited | Energy | 2020 |
| Mercia Power Response (Sandy Lane) Limited | Energy | 2016 |
| Mercia Power Response (Sookholme Road) Limited | Energy | 2019 |
| Mercia Power Response (Station Road) Limited | Energy | 2023 |
| Mercia Power Response (the Wood Yard) Limited | Energy | 2016 |
| Mercia Power Response (Trading) Limited | Energy | 2022 |
| Mercia Power Response (Wellington Road) Limited | Energy | 2019 |
| Mercia Power Response (Whittington Road) Limited | Energy | 2016 |
| Mercia Power Response (Woolaston Road) Limited | Energy | 2020 |
| Mercia Power Response (Worcester Road) Limited | Energy | 2022 |
| Mercia Power Response Limited | Energy | 2015 |
| Mercia Recruitment Limited | Administrative & support | 2017 |
| Mercia Skin Ltd | Other services | 2025 |
| Mercia Social Care Limited | Administrative & support | 2017 |
| Mercia Solutions Limited | Information & communication | 2017 |
| Mercia Strategies Ltd | Professional & scientific | 2015 |
| Mercia Swan Limited | Administrative & support | 2018 |
| Mercian Archaeological Services CIC | Professional & scientific | 2013 |
| Mercian Food Projects Limited | Professional & scientific | 2025 |
| Mercol Engineering Ltd | Manufacturing | 2005 |
| Mercuri Holdings UK Limited | Information & communication | 2024 |
| Mercury Cleaning Solutions Ltd | Administrative & support | 2007 |
| Mercury Fire and Security Limited | Administrative & support | 2002 |
| Mercury Floats Limited | | 1977 |
| Mercurytcg Ltd | Wholesale & retail | 2024 |
| Mercy Care Services & Staffing Ltd | Administrative & support | 2026 |
| Mercy Food & Wine Limited | Wholesale & retail | 2023 |
| Merebrook Developments Limited | Construction | 2025 |
| Meredith Tailors Limited | Manufacturing | 2003 |
| Merg Retreats Limited | Arts & recreation | 2019 |
| Mergz Enterprises Limited | Financial services | 2021 |
| Mergz Limited | Administrative & support | 2022 |
| Meribel Group Holdings Ltd | Financial services | 2015 |
| Meribel Investments Ltd | Real estate | 2015 |
| Merida Bicycles Limited | Wholesale & retail | 1995 |
| Meridian Living Ltd | Public administration | 2025 |
| Meridian Strategies Limited | Information & communication | 2024 |
| Meridian Waterside Ltd | Construction | 2025 |
| Meridion Systems Ltd | Professional & scientific | 2026 |
| Meridius Solutions Ltd | Other services | 2026 |
| Merit Frost Co Ltd | Real estate | 2025 |
| Merit Recycling Ltd | Water & waste | 2025 |
| Merit Tool Hire & Sales Limited | Administrative & support | 2003 |
| Merixa Limited | Professional & scientific | 2026 |
| Merkam Limited | Construction | 2003 |
| Merkator Ltd | Wholesale & retail | 2020 |
| Merletra Services Limited | Real estate | 2023 |
| Merlin Audio Visual Limited | Other services | 2016 |
| Merlin Corporate Finance Limited | Administrative & support | 2017 |
| Merlin GAS Ltd | Administrative & support | 2020 |
| Merlin Shoes Limited | Administrative & support | 2017 |
| Merlion Associates Ltd | Real estate | 2017 |
| Mermaid Consulting Limited | Information & communication | 2021 |
| Merrick-Ed Limited | Professional & scientific | 2022 |
| Merriday Consulting Limited | Professional & scientific | 2013 |
| Merripet Ltd | Professional & scientific | 2012 |