| LP Consultants Property Ltd | Administrative & support | 2024 |
| LPT Electrical Limited | Construction | 2013 |
| Lrow Ltd | Real estate | 2025 |
| Ls-Y Brand Consultancy Limited | Administrative & support | 2007 |
| LSK Accountancy Ltd | Professional & scientific | 2011 |
| Lst-Construction Ltd | Construction | 2021 |
| LT Consultancy London Limited | Professional & scientific | 2014 |
| LTC Comms Ltd | Information & communication | 2017 |
| LTG Construction Services Limited | Construction | 2022 |
| Luba Developments Ltd | Administrative & support | 2017 |
| Luca Drylining Ltd | Construction | 2021 |
| Lucas Shine Ltd | Administrative & support | 2026 |
| Lucasone Services Ltd | Construction | 2024 |
| Lucid Disposables USA Ltd | Wholesale & retail | 2023 |
| Lucy Does Art Ltd | Professional & scientific | 2022 |
| Lucy Page Ltd | Professional & scientific | 2025 |
| Lugenguel Limited | Professional & scientific | 2024 |
| Lumea Vitality Ltd | Wholesale & retail | 2026 |
| Lumia Investments Ltd | Financial services | 2020 |
| Lumia Italia Trading Ltd | Administrative & support | 2017 |
| Lumiere Court (Freehold) Limited | Real estate | 2006 |
| Lumiere Court Management Limited | Real estate | 2024 |
| Luminous Private Limited | Health & social care | 2014 |
| Lumizer Eateries Limited | Hospitality | 2018 |
| Luna Sound and Lighting Limited | Wholesale & retail | 2019 |
| Lunar Labs AI Ltd | Professional & scientific | 2025 |
| Lusso Prestige Limited | Wholesale & retail | 2016 |
| Luvforever Fashion Limited | Wholesale & retail | 2017 |
| Luxaera Ltd | Manufacturing | 2026 |
| Luxavia Jewels Ltd | Wholesale & retail | 2025 |
| Luxeatel Ltd | Wholesale & retail | 2025 |
| Luxenest Nannies Limited | Administrative & support | 2025 |
| Luxury Carpets Trading Limited | Wholesale & retail | 2022 |
| Luxury Destination Parties Ltd. | Administrative & support | 2024 |
| Luxury Metaverse Limited | Information & communication | 2022 |
| LVU Ltd | Construction | 2026 |
| Lyfthelm Ltd | Administrative & support | 2010 |
| Lynchmoor (Leasehold) Limited | Construction | 2011 |
| Lynchmoor (Properties) Limited | Construction | 1986 |
| Lynda Rhodes Designs Limited | Arts & recreation | 1974 |
| Lynette Orman Limited | Information & communication | 2007 |
| Lynley Consulting Limited | Professional & scientific | 2019 |
| Lyntex Limited | Wholesale & retail | 2012 |
| Lyonwood 11 Ltd | Real estate | 2019 |
| Lyonwood Estates Limited | Construction | 2015 |
| Lyonwood HR Limited | Real estate | 2019 |
| Lyonwood HYP Ltd | Real estate | 2020 |
| Lyonwood Investments Limited | Real estate | 2015 |
| Lyonwood JC Limited | Real estate | 2021 |
| Lyonwood Limited | Construction | 2015 |
| Lyonwood Properties Limited | Construction | 2015 |
| M & a Events Ltd | Arts & recreation | 2014 |
| M & B Building Solutions Limited | Construction | 2014 |
| M & K Family Developments Ltd | Construction | 2018 |
| M & M Builders Ltd | Construction | 1998 |
| M & N Property Developers Ltd | Real estate | 2020 |
| M & S Foods Europe Limited | Wholesale & retail | 2012 |
| M B Brady Construction Ltd | Construction | 2008 |
| M B Brady Properties Limited | Real estate | 2025 |
| M Barbering Limited | Other services | 2015 |
| M Brenyah Consultancy Ltd | Professional & scientific | 2021 |
| M Consultancy Services Ltd | Professional & scientific | 2014 |
| M H Psychological Services Ltd | Education | 2011 |
| M Hunter Properties Limited | Administrative & support | 2013 |
| M J Lighting UK Limited | Wholesale & retail | 2014 |
| M L Healthcare Limited | Real estate | 2011 |
| M L Heating & Plumbing Ltd | Other services | 2014 |
| M M G Bricklayer and General Builders Ltd | Construction | 2007 |
| M N Architecture Studio Limited | Professional & scientific | 2020 |
| M P Financial Ltd | Professional & scientific | 1999 |
| M Roberts Consulting Ltd | Financial services | 2024 |
| M Seth & Co. Ltd | Wholesale & retail | 2016 |
| M Specialist Group Limited | Wholesale & retail | 2024 |
| M Tariq & Sons Ltd | Wholesale & retail | 2019 |
| M Technologies (UK) Limited | Wholesale & retail | 2013 |
| M V Digital Printing Limited | Manufacturing | 2005 |
| M&D Bhatt Limited | Real estate | 2025 |
| M&D Silk Properties Ltd | Real estate | 2010 |
| M&E Medical Center Ltd | Health & social care | 2023 |
| M&I 3 Limited | Financial services | 2026 |
| M&K Health and Nutrition Limited | Health & social care | 2020 |
| M&M Global Distribution Ltd | Professional & scientific | 2024 |
| M&S Cleaning and Property Maintenance Limited | Construction | 2026 |
| M&S Consulting Ltd | Professional & scientific | 2002 |
| M.& H.Barnett & Co.(Property)Limited | Real estate | 1961 |
| M.A.V. Invetment Co Limited | Professional & scientific | 1968 |
| M.C Deco Ltd | Construction | 2019 |
| M.F. Price (Kitchens) Limited | Construction | 1979 |
| M.H.G. Design Limited | Professional & scientific | 1996 |
| M.P. Levene Limited | Wholesale & retail | 1942 |
| M.R.D.Electrical Services Limited | Construction | 2008 |
| M5 Electrical Ltd | Construction | 2023 |
| MA Property Services Limited | Real estate | 2001 |
| Ma.Vi. Digital Ltd | Information & communication | 2021 |
| Maarandal Ltd | Information & communication | 2009 |
| Macari's Limited | Wholesale & retail | 1965 |
| Macgregor Cavendish (UK) Limited | Administrative & support | 2003 |
| Mach 4 Ltd | Administrative & support | 2015 |
| Mack Metalwork Limited | Manufacturing | 2018 |
| Mackenzie Metalcraft Limited | Manufacturing | 2016 |