| Leinster Court Limited | Households | 2002 |
| Lemay Holdings Ltd | Financial services | 2026 |
| Lenar Limited | Professional & scientific | 2021 |
| Leston Close (Block C) Management Company Limited | Households | 1988 |
| Leston Close (Block D) Management Company Limited | Households | 1988 |
| Leston Close (Block E) Management Company Limited | Households | 1988 |
| Lewisham Auto Electrics Limited | Extraterritorial | 1995 |
| Leytonstone Road ( Block "C") Management Company Limited | Households | 1991 |
| Leytonstone Road (Block "B") Management Company Limited | Households | 1991 |
| Leytonstone Road (Block "D") Management Company Limited | Households | 1991 |
| Liam Donnelly Consulting Ltd | Professional & scientific | 2019 |
| Limber 49 Limited | Professional & scientific | 2017 |
| Linden House (Epping) Management Company Limited | Extraterritorial | 2016 |
| Links Labelling Solutions Limited | Wholesale & retail | 2014 |
| Little BEN Limited | Real estate | 2020 |
| Little Chef's Box Ltd | Education | 2020 |
| Littlewood Lock Limited | Professional & scientific | 2013 |
| Livewire Electrics (London) Limited | Construction | 2024 |
| LIW Structures Ltd | Real estate | 2020 |
| LJ Adams Accounting Limited | Professional & scientific | 2020 |
| LJP Civils Ltd | Construction | 2024 |
| LJS Surveying Limited | Professional & scientific | 2025 |
| LKJ Flooring Services Ltd | Construction | 2018 |
| LMD Group Ltd | Financial services | 2024 |
| LMD Skip & Grab Hire Ltd | Water & waste | 2013 |
| LMD Waste Management Ltd | Water & waste | 2015 |
| LML Enterprises Limited | Hospitality | 2019 |
| LMP Developments Ltd | Construction | 2018 |
| LMP Lettings Ltd | Real estate | 2020 |
| Lobban Interiors Limited | Wholesale & retail | 2014 |
| Locate Document Storage Limited | Professional & scientific | 1991 |
| Locate Documents Limited | Public administration | 1993 |
| Location and Studio Services LLP | | 2025 |
| Lochlyn Ltd | Wholesale & retail | 2024 |
| Loft Nation Ltd | Administrative & support | 2017 |
| Logic Link Logistics Ltd | Transport & logistics | 2023 |
| London City PUB Group Limited | Hospitality | 2019 |
| London Indoor Plants Ltd | Wholesale & retail | 2026 |
| Loon Investments | Construction | 2018 |
| Lost World Tattoos Limited | Arts & recreation | 2020 |
| Loughton Construction Limited | Construction | 2012 |
| Louriella Limited | Real estate | 2022 |
| Lovesupps Ltd | Manufacturing | 2025 |
| Lower Street Studios Ltd | Professional & scientific | 2026 |
| Lpit Consultancy Limited | Information & communication | 2025 |
| Lubelska Logistics Limited | Transport & logistics | 2020 |
| Lucy Howman Coaching Ltd | Other services | 2018 |
| Luke's Roofs Ltd | Construction | 2024 |
| Luna Jess Limited | Hospitality | 2026 |
| Luxford Moorings Ltd | Administrative & support | 2015 |
| Lymington & New Forest Builders Ltd | Construction | 2023 |
| Lysanders Antiques and Collectables Ltd | Wholesale & retail | 2025 |
| M & J Hospitality (2024) Ltd | Hospitality | 2023 |
| M & T Plumbing Limited | Construction | 2002 |
| M&V Crane Hire Ltd | Administrative & support | 2022 |
| M. Fuller Limited | Financial services | 2018 |
| M.C Training Provider Limited | Education | 2025 |
| Macintosh Creative Ltd | Professional & scientific | 2011 |
| Mackay Bespoke Limited | Professional & scientific | 2022 |
| Mackay Property Agents Limited | Real estate | 2010 |
| Mackay Property Lettings Limited | Real estate | 2010 |
| Magpire Ltd | Information & communication | 2026 |
| Majesty WIN Limited | Wholesale & retail | 2023 |
| Maltbridge Island Management Company Limited | Other services | 1980 |
| Malting Brown Sunbed Shop Ltd | Other services | 2026 |
| Maltings Place Limited | Real estate | 2002 |
| Malyon & James Heating & Plumbing Ltd | Construction | 2015 |
| Manford Way Management Limited | Households | 1983 |
| Mantar Property Developments Ltd | Real estate | 2022 |
| Maple Park Management Company Limited | Professional & scientific | 2003 |
| Marigold Shipping Services Limited | Other services | 2015 |
| Maritime Arbitration Limited | Financial services | 2013 |
| Mark David Enterprises Limited | Manufacturing | 1986 |
| Marole Homes Ltd | Real estate | 2022 |
| Marshalls Hair & Beauty Limited | Other services | 2014 |
| Marshalltown Ltd | Other services | 2025 |
| Marshland Industrial Cladding Ltd | Other services | 2014 |
| Martin Greenaway Electrical Ltd | Construction | 2017 |
| Martivon Ltd | Hospitality | 2021 |
| Mary Gold Property & Investment Solutions Ltd | Financial services | 2020 |
| MAX Chapman Recruitment Limited | Administrative & support | 2025 |
| MB UK Consultant Limited | Information & communication | 2016 |
| MC Groundworks (London) Limited | Construction | 2026 |
| MCB Software Solutions Limited | Information & communication | 2024 |
| Mccarthy Associates Limited | Professional & scientific | 2005 |
| Mcngb Limited | Real estate | 2016 |
| MCS Plumbing and Heating Limited | Construction | 2021 |
| MD Timber Ltd | Wholesale & retail | 2026 |
| Mead Foods Limited | Wholesale & retail | 2009 |
| Meadows Investments Ltd | Real estate | 2026 |
| Menor Limited | Professional & scientific | 2003 |
| Menthone Place Limited | Households | 1985 |
| Mentus Recruitment Ltd | Administrative & support | 2022 |
| Meridian Contracts Ltd | Information & communication | 2015 |
| Mermane Hair Limited | Other services | 2019 |
| Mezmai Limited | Real estate | 2025 |
| Mezmai Property LLP | | 2021 |
| MG Accounting Business Solutions Ltd | Professional & scientific | 2025 |
| MGD Contract Solutions Limited | Professional & scientific | 2020 |
| MHL Electrical Ltd | Construction | 2023 |