| Living Flame Limited | Manufacturing | 2023 |
| Living Saucha Ltd | Education | 2018 |
| Living Within Reach Limited | Hospitality | 2017 |
| Lizzy Bikes Limited | Wholesale & retail | 2025 |
| Ljoc Consulting Ltd | Other services | 2026 |
| LJS One Holdings Limited | Administrative & support | 2023 |
| LJS Removals Ltd | Transport & logistics | 2025 |
| LK Hair & LK Beauty Limited | Other services | 2010 |
| LLE Property Services Ltd | Real estate | 2021 |
| Lloyd Davenport Limited | Construction | 1968 |
| LM Retail Ltd | Wholesale & retail | 2021 |
| LMB Quality Limited | Professional & scientific | 2007 |
| Lobo Investments Holdings Limited | Information & communication | 2022 |
| Lobojet Ltd | Information & communication | 2024 |
| Local Heritage Books Limited | Professional & scientific | 1989 |
| Local Maxima Ltd | Professional & scientific | 2019 |
| Localisr Ltd | Information & communication | 2023 |
| Localllama Ltd | Wholesale & retail | 2025 |
| Lockie Consultants (UK) Limited | Administrative & support | 2011 |
| Lockside Place Management Limited | Households | 2018 |
| Logan Capital Limited | Real estate | 2024 |
| Lomagundi Construction Services Ltd | Construction | 2024 |
| London & Reading Developments Limited | Construction | 1959 |
| London & Sheffield Developments Limited | Extraterritorial | 1997 |
| London Contract Services Limited | Administrative & support | 1997 |
| London Hydraulic Power Company (the) | Information & communication | 1981 |
| London Strand Ltd | Real estate | 2014 |
| London Travel Tour Ltd | Wholesale & retail | 2019 |
| Long Barn Estates Ltd | Hospitality | 2022 |
| Long Term Canal Boat Hire Ltd | Arts & recreation | 2022 |
| Loose Tongue Designs Ltd | Manufacturing | 2024 |
| Lost in Yoga Ltd | Health & social care | 2015 |
| Lottonet Limited | Arts & recreation | 1996 |
| Lottoweb Limited | Arts & recreation | 1996 |
| Louise Lumsden Consulting Limited | Real estate | 2026 |
| Lovejoy Stevens Berkshire Limited | Real estate | 2002 |
| Lovejoy Stevens Holdings Limited | Real estate | 2002 |
| Lovelly Ltd | Wholesale & retail | 2010 |
| Lovely Light Limited | Professional & scientific | 2002 |
| Lovelyland Productions Ltd | Information & communication | 2013 |
| Loving Monday Limited | Professional & scientific | 2011 |
| Lowbury Properties Ltd | Real estate | 2023 |
| Loyd's Electrical Services Ltd | Construction | 2026 |
| LP Davis Installations Limited | Construction | 2019 |
| Lprs Connected Solutions Limited | Information & communication | 2016 |
| LS Fire Solutions Ltd | Professional & scientific | 2015 |
| LSL Services Ltd | Real estate | 2019 |
| LUA Nova Ltd | Wholesale & retail | 2021 |
| Luchy Concepts Limited | Manufacturing | 2026 |
| Lucky Taxis Ltd | Other services | 2024 |
| Ludecs Ltd | Information & communication | 2019 |
| LUI Yeung Acupuncture Ltd | Health & social care | 2023 |
| Lukas Pasternak Limited | Transport & logistics | 2014 |
| Luke Bangs Ltd | Wholesale & retail | 2023 |
| Luker Court RTM Company Limited | Households | 2025 |
| Lumar Consultancy Ltd | Professional & scientific | 2015 |
| Lumina Corporate Limited | Wholesale & retail | 2025 |
| LUMINOR3 Limited | Information & communication | 2020 |
| Luminous Films Ltd | Information & communication | 2019 |
| Luna TOO Limited | Wholesale & retail | 2012 |
| Lunar X UK Ltd | Information & communication | 2021 |
| Lush PAD Ltd | Real estate | 2020 |
| LUX Papillon Limited | Professional & scientific | 2018 |
| Luxe 88 Limited | Other services | 2022 |
| Luxee London Ltd | Wholesale & retail | 2024 |
| LW Taverns Ltd | Hospitality | 2023 |
| Lydden Management Limited | Other services | 2003 |
| Lyde Court Management Company Ltd | Households | 2022 |
| Lydiard Service Station Limited | Other services | 2022 |
| LZ Total Interiors Solutions Ltd | Construction | 2018 |
| M & C Landscapes Ltd | Administrative & support | 2013 |
| M a Fishlock Transport Limited | Transport & logistics | 2009 |
| M C Turner and SON Ltd | Wholesale & retail | 2008 |
| M G Heating Services Limited | Construction | 2009 |
| M J Flitter Landscapes Ltd | Construction | 2013 |
| M P K Transport Ltd | Transport & logistics | 2013 |
| M P Walden Electrical Limited | Construction | 2014 |
| M Y a Solutions Ltd | Administrative & support | 2015 |
| M Y Akbar UK Limited | Professional & scientific | 2025 |
| M&J Silkroad Trading Ltd | Wholesale & retail | 2024 |
| M&R Advisory Group Limited | Professional & scientific | 2025 |
| M. Hawkins (Construction) Limited | Construction | 1999 |
| M. J. F. Properties Limited | Real estate | 1996 |
| M. T. Hayward Limited | Manufacturing | 2002 |
| M.Mae Ltd | Construction | 2023 |
| M.O. Byrd Estates Limited | Real estate | 1995 |
| M4 Communications Ltd | Other services | 2017 |
| M4 HR Ltd | Administrative & support | 2016 |
| M888SRB Ltd | Administrative & support | 2025 |
| M92 Limited | Information & communication | 2019 |
| Mabel Luke Trustee Limited | Professional & scientific | 2016 |
| Macaron Land Ltd | Information & communication | 2025 |
| Macgee Brothers(Estate Agents)Limited | Real estate | 1934 |
| Mach 2 Lighting Ltd | Arts & recreation | 2024 |
| Maciver Management Ltd | Professional & scientific | 2011 |
| Mackinnon Training Limited | Education | 2009 |
| Mackintosh's Catering Management Limited | Hospitality | 2004 |
| Madison Boston Property Limited | Real estate | 2003 |
| MAG Cyber Limited | Information & communication | 2022 |
| Magellan Point Limited | Information & communication | 2020 |