| LT Prime Properties Ltd | Real estate | 2026 |
| Luca Sky Ltd | Extraterritorial | 2020 |
| Lucy Mitchell Mrcvs Limited | Professional & scientific | 2023 |
| Ludus Promotions Ltd | Education | 2024 |
| Luka Property Management Limited | Real estate | 2015 |
| Lume Africa Limited | Professional & scientific | 2025 |
| Lunarphp Ltd | Information & communication | 2020 |
| Lung Landscapers Limited | Administrative & support | 2024 |
| Lung Landscaping Limited | Administrative & support | 2023 |
| Lushlash Ltd | Other services | 2018 |
| Lushlash Training Academy Ltd | Education | 2019 |
| Lussati Media Ltd | Information & communication | 2024 |
| Lusso Aesthetics & Beauty Ltd | Other services | 2024 |
| Lutine Consulting Limited | Professional & scientific | 2015 |
| LUX Law Ltd | Professional & scientific | 2013 |
| Luxcool Limited | Real estate | 2013 |
| Luxland Capital Ltd | Real estate | 2024 |
| Luxnightzz Ltd | Hospitality | 2020 |
| Lynn Servicing Limited | Transport & logistics | 1993 |
| M & B Building & Refurbishment's Limited | Construction | 2025 |
| M & B Maintenance & Services Ltd | Construction | 2025 |
| M & D Family Dental Limited | Health & social care | 2023 |
| M & G Fire Protection (Essex) Limited | Public administration | 2000 |
| M & G Property (Essex) Limited | Real estate | 2017 |
| M & N Property and Investments Limited | Real estate | 2019 |
| M a Scaffolding Services Ltd | Construction | 2023 |
| M B S Grounds Maintenance Ltd | Administrative & support | 2003 |
| M G J Engineering Limited | Manufacturing | 2009 |
| M H Dunn & Sons Forestry Contractors LLP | | 2022 |
| M P Blackwell & Company Limited | Extraterritorial | 2023 |
| M UK Holdco Limited | Financial services | 2024 |
| M&Ds Groundworks & Construction Ltd | Construction | 2025 |
| M&E Group Ltd | Construction | 2017 |
| M&G Welding Ltd | Construction | 2018 |
| M&M Community Outreach CIC | Health & social care | 2026 |
| M&M Homestore Limited | Wholesale & retail | 2022 |
| MA Cleaning Services Limited | Administrative & support | 2024 |
| Mackie Door Consultancy Ltd | Construction | 2019 |
| Mahabat Ltd | Hospitality | 2023 |
| Maine Scaffolding Services Ltd | Construction | 2008 |
| Mainstay Cambridge Limited | Hospitality | 2019 |
| Majesty Housing Ltd | Real estate | 2024 |
| MAK5 Limited | Professional & scientific | 2012 |
| Mako Resources Ltd | Construction | 2019 |
| Malaga Removals Ltd | Transport & logistics | 2015 |
| Malbar Limited | Financial services | 2020 |
| Maldon Curry Limited | Hospitality | 2025 |
| Maldon Fruit Supplies Limited | Wholesale & retail | 2026 |
| Maleto Ltd | Information & communication | 2014 |
| Mallorca Removals Limited | Transport & logistics | 2017 |
| Mama Dells Ltd | Hospitality | 2025 |
| Mama Dells of Witham Ltd | Hospitality | 2025 |
| Manchester Internet Services Limited | Professional & scientific | 1995 |
| Mand Capital Limited | Real estate | 2024 |
| Mango Accountancy Ltd | Professional & scientific | 2018 |
| Mansfield L.P.A. Ltd | Real estate | 2013 |
| Marchprop UK Limited | Real estate | 2019 |
| Marcus Jackson Limited | Professional & scientific | 2018 |
| Marine Support and Management Limited | Administrative & support | 2010 |
| Maritime Art Partners Ltd | Wholesale & retail | 2012 |
| Mark Blessing Limited | Health & social care | 2020 |
| Marketing Grin Limited | Information & communication | 2009 |
| Markham & Smith MOT Centre Limited | Wholesale & retail | 2026 |
| Markham and Smith Motor Engineers Limited | Wholesale & retail | 1982 |
| Marks Mobility Centre Limited | Wholesale & retail | 2005 |
| Marlings Partnership Ltd | Real estate | 2017 |
| MARN28 Ltd | Health & social care | 2023 |
| Marshall Scott Interiors Limited | Wholesale & retail | 2015 |
| Martin Hardy & Sons Limited | Other services | 2001 |
| Martin's Scaffolding Ltd | Construction | 2015 |
| Masala UK Ltd | Hospitality | 2024 |
| Masibanda Limited | Information & communication | 2024 |
| Mason Construction (London) Ltd | Construction | 2010 |
| Massey Motors Ltd | Wholesale & retail | 2017 |
| Massey Safeguarding Solutions Limited | Professional & scientific | 2026 |
| Matrix Communications Limited | Information & communication | 2003 |
| Matthew Calvin Limited | Professional & scientific | 2014 |
| Matthews Commercial Advisory Ltd | Professional & scientific | 2026 |
| Mavi Ltd | Hospitality | 2025 |
| Maxen Recruitment Ltd | Administrative & support | 2020 |
| Mayes Lane Estates Ltd | Real estate | 2024 |
| Mayes Lane Management Company Limited | Real estate | 2022 |
| Mayes Lane Properties Ltd | Real estate | 2023 |
| Mayes Lane Realty Ltd | Real estate | 2025 |
| Mayes Lane SPV Ltd | Construction | 2020 |
| Mayes Lane SPV Phase 3 Ltd | Construction | 2023 |
| Mayflower Construction Ltd | Construction | 2021 |
| MBC Contracts Ltd. | Construction | 1993 |
| Mbjd Projects Limited | Construction | 2019 |
| Mbsgm Group Limited | Financial services | 2024 |
| MCC Building Consultants Limited | Construction | 2016 |
| MDB Prime Properties Ltd | Real estate | 2025 |
| MDH Consultancy Ltd | Professional & scientific | 2018 |
| MDN Fitness Ltd | Arts & recreation | 2021 |
| Med-Fx Ltd | Administrative & support | 2006 |
| Meditec Medical Services Ltd | Health & social care | 2023 |
| MEE Building Solutions Limited | Administrative & support | 2017 |
| Mellegro Ltd | Arts & recreation | 2023 |
| Memorielle Ltd | Wholesale & retail | 2024 |
| Mena Solvents Limited | Extraterritorial | 2020 |