| MDW Lets Ltd | Real estate | 2023 |
| ME Building and Maintenance Limited | Construction | 2015 |
| ME Holding Group Limited | Real estate | 2020 |
| ME Property Services Limited | Hospitality | 2020 |
| MEA Films Ltd | Information & communication | 2018 |
| Meachin Masonry Limited | Construction | 2016 |
| Mead Fields (Phase 2) Weston Parklands Management Company Limited | Households | 2020 |
| Mead Lettings Management Ltd | Real estate | 2018 |
| Mead Security Limited | Administrative & support | 2018 |
| Meadow Accounts & Bookkeeping Services Ltd | Professional & scientific | 2020 |
| Meadow Acre Management Limited | Households | 2026 |
| Meadow Care Homes Ltd | Health & social care | 2005 |
| Meadow House Management Company Limited | Professional & scientific | 2000 |
| Meadow Landscapes Limited | Administrative & support | 2015 |
| Meadow LEA Management Limited | Households | 2021 |
| Meadow Mini Ltd | Wholesale & retail | 2025 |
| Meadow Property Solutions Limited | Real estate | 2015 |
| Meadow View (Paulton) Management Company Limited | Households | 2019 |
| Meadow Way (Baileys Court) Limited | Households | 1992 |
| Meadow Way (Sherbourne) Limited | Households | 1991 |
| Meadow Wood Pet Cremations Ltd | Financial services | 2024 |
| Meadowfort Grange Management Company (Winchcombe) Limited | Real estate | 2014 |
| Meadowgrove Construction Limited | Construction | 2019 |
| Meadowlands Property Management Ltd | Households | 2025 |
| Meadows Farm Bath Limited | Real estate | 2025 |
| Meadows Manor Enterprises Ltd | Hospitality | 2015 |
| Meads Building & Renovation Limited | Construction | 2002 |
| Mealcraft Digital Ltd | Information & communication | 2026 |
| Mealing Plumbing & Heating Ltd | Construction | 2024 |
| Mealmapper Ltd | Information & communication | 2026 |
| Mealnest Ltd | Hospitality | 2024 |
| Meaning Machine Games Ltd | Information & communication | 2024 |
| Meaning Machine Ltd | Information & communication | 2022 |
| Meaningful Measures Ltd | Professional & scientific | 2020 |
| Meaningful Numbers Ltd | Administrative & support | 2009 |
| Meanwhile Creative (Bristol) Ltd | Real estate | 2024 |
| Meanwhile Creative Ltd | Real estate | 2011 |
| Meanwhile Projects Ltd | Administrative & support | 2020 |
| Mearley Vets Limited | Extraterritorial | 2010 |
| Mears Air Conditioning Ltd | Professional & scientific | 2022 |
| Measure to Made Ltd | Manufacturing | 2026 |
| MEB2 Ltd | Transport & logistics | 2021 |
| Mebc Ltd | Information & communication | 2011 |
| Mebrap Ltd | Manufacturing | 2019 |
| Mebtech Limited | Construction | 2016 |
| Mech-Therm Ltd | Extraterritorial | 2022 |
| MECH3D Design Ltd | Professional & scientific | 2018 |
| Mecha Technology Limited | Manufacturing | 2025 |
| Mechanica & Maker Ltd | Professional & scientific | 2020 |
| Mechanimal Arts CIC | Arts & recreation | 2021 |
| Mechanova Design Limited | Professional & scientific | 2024 |
| Mechatronic Innovations Limited | Professional & scientific | 2018 |
| Mechelec Commissioning Services Limited | Construction | 2010 |
| Mechfeed Ltd | Information & communication | 2013 |
| Mechine Enterprise Limited | Manufacturing | 2021 |
| Mecsol Ltd | Construction | 2002 |
| MED Flavours UK Limited | Hospitality | 2011 |
| MED LAB Partners Ltd | Professional & scientific | 2023 |
| MED Staff International Limited | Administrative & support | 2023 |
| Med-Crops (UK) LLP | | 2019 |
| Medable UK Limited | Information & communication | 2023 |
| Medaco (Holdings) Ltd | Professional & scientific | 2014 |
| Medaco Ltd | Wholesale & retail | 2014 |
| Medaspire Limited | Education | 2024 |
| Medavia Limited | Information & communication | 2003 |
| Medcura Limited | Financial services | 2025 |
| Medex Supply UK Limited | Wholesale & retail | 2020 |
| Medholic Ltd | Information & communication | 2026 |
| Medi-Care Media Ltd | Health & social care | 2025 |
| Medi-Munz Limited | Manufacturing | 2016 |
| Media Cake Limited | Information & communication | 2013 |
| Media Focus UK Limited | Information & communication | 2009 |
| Media Maintenance Company Limited | Construction | 2001 |
| Media Translation Limited | Professional & scientific | 2015 |
| Media Tube Limited | Information & communication | 2003 |
| Mediacomx Ltd. | Manufacturing | 2016 |
| Mediagun Ltd | Information & communication | 2020 |
| Mediatopia Limited | Professional & scientific | 2010 |
| Mediatopia Solutions Limited | Information & communication | 2010 |
| MEDIC24 Ltd | Administrative & support | 2025 |
| Medical Assured Group Limited | Wholesale & retail | 2020 |
| Medical CPD Ltd | Information & communication | 2023 |
| Medical GAS Pipeline Services Ltd | Health & social care | 2022 |
| Medicaldirector Limited | Information & communication | 2018 |
| Medicall Health Ltd | Health & social care | 2021 |
| Medicalrehabilitation Ltd | Health & social care | 2018 |
| Medico Lifestyle Limited | Wholesale & retail | 2018 |
| Medico-Dental Holdings Limited | Financial services | 2011 |
| Medico-Legal Admin Support Limited | Administrative & support | 2026 |
| Medicollective Ltd | Health & social care | 2009 |
| Medics Innovate Limited | Manufacturing | 2024 |
| Medieval Nexus Ltd | Extraterritorial | 2020 |
| Medilink Limited | Wholesale & retail | 1989 |
| Medilink South West Limited | Administrative & support | 2012 |
| Medilux Media Solutions Limited | Administrative & support | 2023 |
| Medimpetus Limited | Information & communication | 2025 |
| Medincle Ltd. | Information & communication | 2013 |
| Medip Country Store and Equine Limited | Wholesale & retail | 2016 |
| Mediplastuk Ltd | Health & social care | 2019 |
| Medisort Limited | Water & waste | 2009 |