| Lizelle Keyser OT Limited | Health & social care | 2019 |
| LJ Creative, Buying & Sourcing Limited | Professional & scientific | 2021 |
| LJS Systems Limited | Information & communication | 2015 |
| Location Lighting (London) Limited | Other services | 1966 |
| Lock Keepers Walk (Tipton) Management Company Limited | Households | 2004 |
| Lock View Management Company Limited | Real estate | 2019 |
| Locks Stock and More Limited | Wholesale & retail | 2019 |
| Lockside (Northampton) Management Company Limited | Households | 2006 |
| Loel Limited | Administrative & support | 2020 |
| Logan Place Management Limited | Households | 2001 |
| Logistics and Business Management Limited | Transport & logistics | 2018 |
| Lokularentals Ltd | Administrative & support | 2025 |
| Lond Media Planning and Purchasing Ltd | Administrative & support | 2021 |
| London Developments & Management Ltd | Real estate | 2018 |
| London FMT Centre Limited | Extraterritorial | 2017 |
| London Green (194-199) Management Limited | Households | 1986 |
| London Green (200-205) Management Limited | Households | 1986 |
| London Green (68-73) Management Limited | Households | 1987 |
| London Hearts Aerial Services Ltd | Construction | 2006 |
| London Overseas Consultancy Limited | Real estate | 1998 |
| London Overseas Estates Limited | Real estate | 2003 |
| London Property Investments (.COM) Limited | Real estate | 2011 |
| London Road (Apsley C) Management Company Limited | Households | 2002 |
| London Road (Buntingford) Management Company Limited | Households | 2015 |
| London Stone Limited | Construction | 2002 |
| London Toy Shop Events Ltd | Administrative & support | 2025 |
| London Toy Shop Limited | Extraterritorial | 2025 |
| Longfield Park (Chineham) Management Company Limited | Households | 2005 |
| Longlands Mill Management Company Limited | Households | 2008 |
| Lord Project Solutions Ltd | Professional & scientific | 2026 |
| Lord Street London Ltd | Hospitality | 2024 |
| Lordship Cooker Centre Limited | Wholesale & retail | 1997 |
| Lore&Co Ltd | Wholesale & retail | 2025 |
| Louise Pearson Communications Limited | Professional & scientific | 2014 |
| Lounes Cherik Ltd | Hospitality | 2021 |
| Lourd Property Maintenance Ltd | Real estate | 2012 |
| Love Hoddesdon BID Ltd | Other services | 2018 |
| Love London Apartments Agency Limited | Hospitality | 2014 |
| Love Walkies Ltd | Other services | 2015 |
| Lovedon Lane Management Limited | Households | 2010 |
| LOW Hill Nursery Ltd | Agriculture & fishing | 2018 |
| Lowewood Pottery Club Ltd | Other services | 2024 |
| Lowood (Wilmslow) Management Company Limited | Households | 2023 |
| LPC Property Ventures Ltd | Real estate | 2022 |
| Lrsa Ltd | Other services | 2024 |
| LSG Protection Ltd | Financial services | 2024 |
| LT and Sons Properties Limited | Real estate | 2022 |
| Lucca Rising Sports Group Ltd | Arts & recreation | 2025 |
| Lucky World Ltd | Wholesale & retail | 2024 |
| Lucy Glenn Creative Ltd | Professional & scientific | 2020 |
| LUKA2 Ltd | Construction | 2016 |
| Luke Warm Plumbing & Heating Limited | Construction | 2016 |
| Luna Locations Limited | Professional & scientific | 2024 |
| Luneside Mills (Apartments) Management Company Limited | Households | 2014 |
| Luneside Mills Management Company Limited | Households | 2014 |
| Lungo Lets Limited | Real estate | 2018 |
| Lutha Consulting Limited | Professional & scientific | 2026 |
| Luton Town Skips Ltd | Water & waste | 2019 |
| LUX Property Services Limited | Construction | 2012 |
| Luxlap Ltd | Manufacturing | 2023 |
| Luxurious Personal Care Ltd | Manufacturing | 2019 |
| Lyme Vale View (Stoke on Trent) Management Company Limited | Households | 2004 |
| Lyme Zest Limited | Real estate | 2023 |
| Lynmouth Gardens Management Ltd | Households | 2003 |
| Lynton Court (Hatfield) Management Company Limited | Households | 2005 |
| Lyons Instruments Limited | Extraterritorial | 1968 |
| Lyons Place Management Limited | Households | 2004 |
| M & a Canna Limited | Professional & scientific | 2025 |
| M & M Welding and Fabrication Ltd | Manufacturing | 2004 |
| M Bodyworks Limited | Wholesale & retail | 2016 |
| M CAP Management Limited | Real estate | 2026 |
| M F Rudd Plumbing Heating & Building Services Ltd | Construction | 2015 |
| M Henry Ltd | Wholesale & retail | 2009 |
| M J Brand Electrical Ltd | Construction | 2018 |
| M J Game Limited | Construction | 2013 |
| M S Z Building Services Limited | Construction | 2008 |
| M Squared Construction & Refurbishment Limited | Construction | 2024 |
| M Tech Networks Limited | Manufacturing | 2012 |
| M V Productions Limited | Professional & scientific | 2013 |
| M Way Group Limited | Water & waste | 2021 |
| M&L Property Management Ltd | Construction | 2023 |
| M&M Investment Properties Ltd | Real estate | 2020 |
| M.J. Steel Site Services Limited | Manufacturing | 2015 |
| M.Storm Haulage Ltd | Transport & logistics | 2020 |
| M2 Partnership Limited | Administrative & support | 2019 |
| M3 GAS Ltd | Extraterritorial | 2017 |
| MA Project Services Limited | Construction | 2020 |
| Mabelhr Ltd | Professional & scientific | 2012 |
| Macmillan Editorial Limited | Information & communication | 2026 |
| MAG7 Ventures Ltd | Information & communication | 2025 |
| Magic Mezzanine Floors Ltd. | Construction | 2008 |
| Maida Residents Management Company Limited | Households | 2022 |
| Maison AGI Ltd | Wholesale & retail | 2026 |
| Maison Tatia Ltd | Manufacturing | 2017 |
| Majors Banquet Ltd | Manufacturing | 2023 |
| Make Infrastructure Great Again Ltd | Information & communication | 2024 |
| Maker & Mind Ltd | Arts & recreation | 2025 |
| Makur Trans Limited | Transport & logistics | 2015 |
| Malbern Limited | Real estate | 1995 |
| Malie Company Limited | Other services | 2023 |