| MDJ Truck Ltd. | Transport & logistics | 2019 |
| Meadow View (ST Margaret's) Management Ltd | Households | 2017 |
| Meadows-Hannent Ltd | Hospitality | 2025 |
| Meagher Consultancy Ltd | Professional & scientific | 2022 |
| Mechanica Utilities Ltd | Manufacturing | 2015 |
| Medical Engineering Technologies Ltd. | Professional & scientific | 1996 |
| Medius Enterprises Ltd | Administrative & support | 2011 |
| Megawaw Ltd | Information & communication | 2023 |
| Megger Grid Analytics Limited | Manufacturing | 2021 |
| Megger Instruments Limited | Manufacturing | 1923 |
| Megger Systems Limited | Manufacturing | 2020 |
| Mems Studio Ltd | Extraterritorial | 2025 |
| Menuiserie ABM Construct Ltd | Extraterritorial | 2016 |
| Merdini Invest Ltd | Extraterritorial | 2026 |
| Merdini Ltd | Extraterritorial | 2026 |
| Meridian Financial Planning Limited | Financial services | 2013 |
| Meso Corp UK Ltd | Extraterritorial | 2017 |
| Mesopotamian Music Corporation Holding Ltd | Extraterritorial | 2017 |
| Metaverse Future Ltd | Wholesale & retail | 2021 |
| Meumfidet Ltd | Professional & scientific | 2021 |
| MF Begin PLC | Extraterritorial | 2011 |
| MGP Property Developments Limited | Real estate | 2026 |
| Mgpa Real Estate Special Situations Fund, L.P. | | 2008 |
| MHC Brickwork Ltd | Construction | 2025 |
| Michael Barker Controls Ltd | Construction | 2022 |
| Michael RIX Building Limited | Construction | 2015 |
| Micodan Ltd | Construction | 2018 |
| Microtone UK Limited | Wholesale & retail | 2001 |
| Midas Hygienic Solutions Ltd | Construction | 2019 |
| Midas Industrial Ltd | Manufacturing | 2025 |
| Middleton and Sons Construction Limited | Construction | 2023 |
| Middleton Tipper Services Limited | Construction | 2020 |
| Midlane West Limited | Administrative & support | 2013 |
| Milan Barber Shop Ltd | Other services | 2019 |
| Mile 2 Ltd. | Arts & recreation | 2017 |
| Milk&Honey LDN LLP | | 2017 |
| Millennium Computer Consultancy Limited | Professional & scientific | 1999 |
| Millie's Hair and Beauty Salon Limited | Other services | 2017 |
| Millside View Ltd | Construction | 2012 |
| Millview Builders Limited | Construction | 2018 |
| Mimo Renovation Invest Ltd | Extraterritorial | 2023 |
| Mimo Renovation Ltd | Extraterritorial | 2023 |
| Minty Mouse Ltd | Arts & recreation | 2025 |
| Mister Elizabeth Limited | Real estate | 2010 |
| Mitre Consulting Ltd | Professional & scientific | 2025 |
| MJ Friend Haulage Ltd | Transport & logistics | 2019 |
| Mj-Company Invest Ltd | Information & communication | 2025 |
| MJS Carpentry & Construction Limited | Manufacturing | 2024 |
| MKC Design Ltd | Administrative & support | 2020 |
| Mkpps Realty Limited | Real estate | 2025 |
| ML Catering Services Ltd | Hospitality | 2026 |
| MLN Audio Visuel Ltd | Professional & scientific | 2019 |
| MLN Belgique Ltd | Arts & recreation | 2015 |
| MLN Business International Ltd | Extraterritorial | 2021 |
| MLN Business Services Ltd | Professional & scientific | 2013 |
| MLN Capital Ltd | Professional & scientific | 2018 |
| MLN Consulting Ltd | Professional & scientific | 2014 |
| MLN International Capital House PLC | Extraterritorial | 2024 |
| MLN Partenaires Boutique Invest Ltd | Extraterritorial | 2024 |
| MLN Partenaires Boutique Ltd | Extraterritorial | 2024 |
| MLN Partners Immo Ltd | Real estate | 2024 |
| MLN Partners Ltd | Professional & scientific | 2023 |
| MMA Rail Consultants Limited | Construction | 2014 |
| Mmarcon Ltd | Wholesale & retail | 2023 |
| MN Global Business Ltd | Professional & scientific | 2019 |
| MNW Commercial Ltd | Wholesale & retail | 2024 |
| Mobile Phone Mechanic Limited | Wholesale & retail | 2013 |
| Mobile Systems Limited | Information & communication | 1997 |
| Modus Vitae Limited | Real estate | 2020 |
| Moira Dawn Limited | Real estate | 2017 |
| Moja Zabka Ltd | Wholesale & retail | 2026 |
| Mondial Players Management Ltd | Arts & recreation | 2015 |
| Moon Keeshond LLC | | 2022 |
| Moorewrights Solutions Ltd | Manufacturing | 2023 |
| Moptic Studios Ltd | Information & communication | 2026 |
| Morgan Pickett Agri Services Ltd | Administrative & support | 2026 |
| MOT Dover Ltd | Wholesale & retail | 2025 |
| Motis Freight Services Limited | Transport & logistics | 2014 |
| Mount Court Residents Association Limited | Real estate | 1998 |
| Movepetris Ltd | Construction | 2023 |
| Moving Memory Dance Theatre Company Ltd | Arts & recreation | 2013 |
| Mowll Limited | Professional & scientific | 2014 |
| MPA Bati Ltd | Extraterritorial | 2022 |
| MPA Gestinvest Ltd | Extraterritorial | 2022 |
| MR Burgers & Wraps Limited | Hospitality | 2024 |
| Mr's Catering Lechon Atbp Ltd | Wholesale & retail | 2023 |
| Mrws Signalling Ltd | Professional & scientific | 2022 |
| MSB Security Training Limited | Administrative & support | 2019 |
| MSC Dover Limited | Professional & scientific | 2013 |
| MSZ PTY Ltd | Real estate | 2022 |
| Muay Thailand Ltd | Wholesale & retail | 2023 |
| Muckell Property Investments Ltd | Real estate | 2019 |
| Muckell Trading Company Ltd | Wholesale & retail | 2017 |
| Multiservice Batiment Ltd | Administrative & support | 2017 |
| Multivers-Intemporel Group Invest Ltd | Extraterritorial | 2023 |
| Multivers-Intemporel Group Ltd | Extraterritorial | 2023 |
| Munro's Plumbing and Heating Limited | Construction | 2019 |
| Murray Parris Ltd | Real estate | 2019 |
| Mustard Seed Properties and Investments Limited | Real estate | 2020 |
| Mutley Plant Service Limited | Wholesale & retail | 1997 |