| Luxury Commercial Clean Ltd | Administrative & support | 2026 |
| Luxury Gardens NY Limited | Administrative & support | 2023 |
| Luxury Shutters Co Limited | Construction | 2017 |
| LV21 Limited | Arts & recreation | 2009 |
| Lwpt Plumbing & Heating Ltd | Professional & scientific | 2022 |
| Lydbrook Limited | Construction | 1981 |
| Lyla Media Ltd | Information & communication | 2024 |
| LYM World Ltd | Health & social care | 2023 |
| Lynnette Properties & Leisure Limited | Hospitality | 2012 |
| Lyonnspedition Ltd | Transport & logistics | 2022 |
| Lyons Heating & Plumbing Ltd | Construction | 2023 |
| M & S Projects Ltd | Construction | 2025 |
| M + E Engineers Limited | Manufacturing | 1998 |
| M B of Medway Limited | Wholesale & retail | 2010 |
| M E Logistics Kent Ltd | Transport & logistics | 2017 |
| M H Ventilation Ltd | Energy | 2023 |
| M Harding Electrical Limited | Construction | 2018 |
| M Hardy Group Limited | Real estate | 2021 |
| M Hardy Properties Limited | Real estate | 2023 |
| M Luxury Wood Flooring Ltd | Construction | 2018 |
| M P Hare Ltd | Construction | 2015 |
| M Protech Limited | Construction | 2023 |
| M S S Contractors Limited | Construction | 1999 |
| M W Productions Ltd | Information & communication | 2019 |
| M W Sweepers Limited | Water & waste | 2009 |
| M Y N Trading Ltd | Wholesale & retail | 2017 |
| M&A Painters and Decorators Ltd | Construction | 2020 |
| M&C Plant Hire Ltd | Administrative & support | 2022 |
| M&P Advisory Limited | Professional & scientific | 2023 |
| M&P Advisory Property Limited | Real estate | 2025 |
| M&S Hospitality Ltd | Hospitality | 2022 |
| M-Shop Palast Limited | Professional & scientific | 2024 |
| M. LEE Chen Associates LP | | 2016 |
| M. W. Ross Limited | Professional & scientific | 2010 |
| M.A.T Roofing Ltd | Construction | 2021 |
| M.B. Landscapes Limited | Other services | 2003 |
| M.E.C.E. Fire & Security Limited | Construction | 2002 |
| M.H. Equipment Limited | Construction | 1993 |
| M.H. Mechanical Handling Limited | Other services | 1999 |
| M.J Building Supplies Ltd | Administrative & support | 2020 |
| M.J. Smith Consulting Limited | Professional & scientific | 2014 |
| M.Mots Service and Repairs Limited | Financial services | 2021 |
| M.Mots Testing Limited | Financial services | 2021 |
| M2 Home Improvements Ltd | Construction | 2018 |
| M2 J2 Ltd | Construction | 2009 |
| M2 Utilities Ltd | Construction | 2016 |
| M4 South East Limited | Real estate | 2024 |
| MA KEE (Hong Kong) Limited | Manufacturing | 2025 |
| MAB Autotech Limited | Administrative & support | 2008 |
| MAC Plas Limited | Wholesale & retail | 2017 |
| Macchiavalley (UK) Limited | Hospitality | 2015 |
| Macfa Logistics Limited | Transport & logistics | 2025 |
| Mach Darts Ltd | Arts & recreation | 2021 |
| Machin Lane Ltd | Real estate | 2023 |
| Machine Safety Testing Ltd | Manufacturing | 2017 |
| Macrotract Holdings Limited | Real estate | 2021 |
| Macsovereign Limited | Real estate | 2026 |
| MAD & Co X Limited | Other services | 2018 |
| Madcat Ltd | Professional & scientific | 2015 |
| Maddy Decor Ltd | Construction | 2018 |
| Madeoko Homes Ltd | Real estate | 2022 |
| Madeoko Limited | Wholesale & retail | 2020 |
| Madgwick Legal Services Ltd | Professional & scientific | 2019 |
| Mads & Co Homes Ltd | Real estate | 2024 |
| Magazine B Property Limited | Real estate | 2023 |
| Magazine B6 Holdings Ltd | Financial services | 2020 |
| Magcrafts Ltd | Construction | 2017 |
| Magic (UK) Limited | Education | 2012 |
| Magnetic Island Limited | Administrative & support | 2014 |
| Magnificent Boutique Ltd | Wholesale & retail | 2019 |
| Magpie Event Solutions Ltd | Professional & scientific | 2023 |
| MAH London Ltd | Construction | 2025 |
| MAI Mortgages Ltd | Financial services | 2022 |
| Maidstone Bars Limited | Hospitality | 2017 |
| Maidstone Carpentry Ltd | Construction | 2024 |
| Maidstone Figureshapers Limited | Transport & logistics | 2003 |
| Maidstone Road Fish Bar Ltd | Hospitality | 2024 |
| Mailspeed Marine Limited | Wholesale & retail | 2026 |
| Mainstone Properties Ltd | Real estate | 2021 |
| Maisie Wilson Transport Services Ltd | Transport & logistics | 2025 |
| Maisoni Foods Limited | Wholesale & retail | 2025 |
| Majek and Sons Ltd | Information & communication | 2025 |
| Majik Marketing Solutions Limited | Professional & scientific | 2012 |
| Major Roadside Recovery Limited | Wholesale & retail | 2026 |
| Make IT Real Simple Limited | Information & communication | 2008 |
| Makhosa Consults Ltd | Professional & scientific | 2025 |
| Making a Difference (South East) Ltd | Health & social care | 2021 |
| Malbe Services Limited | Construction | 2026 |
| Malibu Tanning Retails Ltd | Wholesale & retail | 2023 |
| Malin House RTM Company Limited | Households | 2010 |
| Mamar Health Ltd | Health & social care | 2025 |
| Mams Payments Ltd | Information & communication | 2023 |
| MAN of Kent Freehouse Limited | Hospitality | 2016 |
| MAN Spedition Ltd | Transport & logistics | 2015 |
| Manageable Solutions Ltd | Construction | 2020 |
| Manageio Futuristics Ltd | Information & communication | 2023 |
| Management Innovation Limited | Professional & scientific | 1982 |
| Mandain Global CIC | Other services | 2020 |
| Mannok Build (GB) Limited | Wholesale & retail | 2020 |
| Mannok Cement (GB) Limited | Wholesale & retail | 2020 |