| London Taxi CAM Ltd | Wholesale & retail | 2012 |
| London Wall Design Acoustic Solutions Limited | Construction | 2022 |
| London Wall Design Limited | Construction | 1988 |
| London Wall Group Holdings Limited | Professional & scientific | 2006 |
| London Wall Installations Limited | Construction | 1990 |
| London Wall Services (UK) Ltd | Professional & scientific | 2013 |
| Loui's Maintenance Ltd | Construction | 2012 |
| Louviers House of Beauty Ltd | Other services | 2017 |
| LPA Soccer Academy Ltd | Education | 2024 |
| Lpgpconnect.Com Ltd | Other services | 2020 |
| LPK Learning CIC | Education | 2016 |
| Lucio's Group Ltd | Hospitality | 2020 |
| Lucky Rover Ltd | Hospitality | 2026 |
| Lucy Mair Ltd | Professional & scientific | 2020 |
| Lunch Box Chessington Ltd | Wholesale & retail | 2014 |
| Lura Builders Limited | Construction | 2018 |
| LUX Anna Ltd | Wholesale & retail | 2017 |
| LUX MOA London Ltd | Wholesale & retail | 2021 |
| Luxlonrio Ltd | Administrative & support | 2017 |
| LW Therapy Ltd | Health & social care | 2014 |
| Lyndon House Surbiton Limited | Households | 2010 |
| Lynx Property Developments Limited | Real estate | 2017 |
| M Bentley Construction Management Ltd | Construction | 2026 |
| M I Real Estate Management Limited | Financial services | 2014 |
| M I Vehicles Ltd | Wholesale & retail | 2014 |
| M Weitz Limited | Information & communication | 2017 |
| M.E.M.S. International Limited | Administrative & support | 1988 |
| Maclaren Electrical Ltd | Construction | 2020 |
| Magic Finish Building Service Ltd | Construction | 2020 |
| Magnus Hair Salon Ltd | Other services | 2026 |
| MAH123 Limited | Construction | 2016 |
| Makhlouf Restaurant Lebanon Ltd | Hospitality | 2025 |
| Mallows Design Ltd | Construction | 2022 |
| Manpower Security Limited | Administrative & support | 2026 |
| Maple Publishing Limited | Information & communication | 2009 |
| Maramba Limited | Real estate | 2021 |
| Marchwell Properties Limited | Real estate | 2019 |
| Mark Anthony Farrier Ltd | Arts & recreation | 2025 |
| Market Intelligence AI Ltd | Information & communication | 2025 |
| Marlowe House Limited | Households | 1986 |
| Marshall Survey Associates Limited | Administrative & support | 1998 |
| Martin Masters Ltd | Construction | 2013 |
| Martin VT Ltd | Professional & scientific | 2016 |
| Marysmart Ltd | Information & communication | 2025 |
| Mathsy Education Ltd | Education | 2021 |
| Matrix Legal : Genesis Ltd | Real estate | 2023 |
| Maximo.Wpark Ltd | Hospitality | 2025 |
| Maxpo Limited | Professional & scientific | 2016 |
| Mayfair Roofing Services Ltd | Construction | 2025 |
| MAZ MEZ Ltd | Hospitality | 2014 |
| Maze Business Ltd | Professional & scientific | 2005 |
| MD Innovation & Investments Ltd | Information & communication | 2024 |
| MD Made IT Ltd | Wholesale & retail | 2024 |
| MDF (Vehicle) Maintenance Ltd | Wholesale & retail | 2023 |
| Mdl&Co Ltd | Construction | 2010 |
| MDT - Trade Limited | Construction | 2026 |
| Mebsw Consulting Limited | Professional & scientific | 2021 |
| Melan Barbers Ltd | Other services | 2025 |
| Melan Ltd | Other services | 2026 |
| Melpak Ltd | Wholesale & retail | 2026 |
| Member's Only Ltd | Administrative & support | 2012 |
| MEO (NW) Ltd | Financial services | 2011 |
| Mergeprime Limited | Other services | 2017 |
| Meric to London Ltd | Wholesale & retail | 2020 |
| Meridian & Hearth Ltd | Construction | 2026 |
| Meta Building Limited | Construction | 2022 |
| Meta Investment Holdings Ltd | Manufacturing | 2018 |
| Metalflake Distributors (U.K.) Limited | Professional & scientific | 1978 |
| Metropolitan Fire Systems Ltd | Manufacturing | 2020 |
| Meva Scaffolding Ltd | Construction | 2024 |
| Meximo.Tooting Ltd | Hospitality | 2026 |
| Mezzet Box Limited | Hospitality | 2020 |
| Mezzet Ltd | Hospitality | 2011 |
| MF Financial Consultants Ltd | Professional & scientific | 2024 |
| MHA Home Store Ltd | Wholesale & retail | 2026 |
| MHB & Sons Limited | Construction | 2025 |
| MHC Estates Ltd | Real estate | 2024 |
| Michael Kerr Solutions Ltd | Information & communication | 2017 |
| Micomica Ltd | Wholesale & retail | 2016 |
| Mid-Surrey Windings Limited | Manufacturing | 2001 |
| Midakl Construction Ltd | Construction | 2023 |
| Midas IT (UK) Limited | Information & communication | 2012 |
| Middlemist Flowers Ltd | Wholesale & retail | 2020 |
| Mike Silverwood Architect Ltd | Professional & scientific | 2018 |
| MIL2 Consulting Ltd | Professional & scientific | 2025 |
| Milky Silk Limited | Wholesale & retail | 2014 |
| Milorad Limited | Transport & logistics | 2017 |
| Milton Educational Services Ltd | Education | 2019 |
| Mind Kitchen Ltd | Hospitality | 2026 |
| Mind Rocket Services Ltd | Administrative & support | 2009 |
| Minstrel Gardens RTM Company Limited | Households | 2013 |
| MIP Heating Ltd | Construction | 2017 |
| Miracle Gardens Limited | Education | 2023 |
| Mirasoft Consultancy Limited | Information & communication | 2014 |
| MJ Melodies Ltd | Information & communication | 2023 |
| MK Village Ltd | Wholesale & retail | 2018 |
| Mmsp Ltd | Administrative & support | 2021 |
| MNB Technology UK Limited | Information & communication | 2024 |
| MNK Studio Ltd | Professional & scientific | 2024 |
| Mobile Cctv Solutions Europe Ltd | Wholesale & retail | 2010 |