| London Cocktail Week Ltd | Administrative & support | 2025 |
| London Electrical Contractors Limited | Construction | 1990 |
| London Film & Media Limited | Other services | 2010 |
| London Good News Church Limited | Education | 2006 |
| London Highrise Ltd | Real estate | 2012 |
| London Jewellery Exchange Ltd | Wholesale & retail | 2023 |
| London Pirate Ltd | Professional & scientific | 2007 |
| London School of Arbitration and Dispute Resolution Ltd | Education | 2024 |
| London Scrap Haulage Limited | Transport & logistics | 2025 |
| London Scrap Metal Recycling Express Ltd | Wholesale & retail | 2025 |
| London Security Contractors Ltd | Administrative & support | 2021 |
| London Security Team Ltd | Administrative & support | 2016 |
| London Taxi Consultants Ltd | Administrative & support | 2016 |
| Lone Moor Limited | Real estate | 2017 |
| Long's Locks Ltd | Other services | 2025 |
| Longevity Wellness Limited | Arts & recreation | 2026 |
| Longham Copse (Bearsted) Management Company Limited | Households | 1981 |
| Longitudinal Ltd | Professional & scientific | 2026 |
| Longprofit Limited | Professional & scientific | 1990 |
| Longviewhr Ltd | Administrative & support | 2026 |
| Lonpro Industrial Holdings Limited | Real estate | 2020 |
| Lonpro Ipswich Limited | Real estate | 2022 |
| Lonpro Realestate Holdings Limited | Real estate | 2007 |
| Looknomoore Construction Ltd | Construction | 2022 |
| Lookuptech Ltd | Information & communication | 2016 |
| Loose Glass and Glazing Limited | Wholesale & retail | 2025 |
| Lopchan Traders Ltd | Wholesale & retail | 2020 |
| Loqiva Holdings Limited | Information & communication | 2018 |
| Loqiva Limited | Information & communication | 2018 |
| Lothbury Capital (UK) Limited | Construction | 2023 |
| Lotus Healing Centre Limited | Health & social care | 1989 |
| Loucas Group Limited | Professional & scientific | 2023 |
| Loucas Ltd | Professional & scientific | 1994 |
| Loudr Live Ltd | Information & communication | 2024 |
| Loutopia Planning Services Limited | Financial services | 2021 |
| Love Build Solutions Ltd | Construction | 2018 |
| Love Food Lockmeadow Limited | Administrative & support | 2021 |
| Love This Life Basketball Limited | Education | 2022 |
| Love to Drive Ltd | Extraterritorial | 2024 |
| LOVE&CARE4PETS Ltd | Professional & scientific | 2018 |
| Love&Light Care and Support Limited | Health & social care | 2022 |
| Lovol Tractors Limited | Wholesale & retail | 2017 |
| LOW Friction Solutions Limited | Information & communication | 2022 |
| Lowarn Productions Limited | Information & communication | 2021 |
| Lowder Consultants Limited | Professional & scientific | 2015 |
| Lowry Properties Limited | Real estate | 2026 |
| LP Music Productions Limited | Arts & recreation | 2024 |
| LP Networks Ltd | Information & communication | 2004 |
| LP Pubs & Bars Limited | Hospitality | 2014 |
| LPE Organization Limited(The) | Extraterritorial | 1958 |
| LPK Smart Solutions Ltd | Wholesale & retail | 2020 |
| LPM Power Limited | Construction | 2024 |
| LR Transport Services Ltd | Transport & logistics | 2020 |
| LSL Wood Ltd | Construction | 2024 |
| LSM Wealth Management Ltd | Real estate | 2021 |
| LSP Holdings Limited | Financial services | 2023 |
| LT Tea Limited | Wholesale & retail | 2022 |
| LTJ Surfacing (Southeast) Limited | Construction | 2026 |
| LTT Investments Limited | Real estate | 2023 |
| Lubpm Ltd | Transport & logistics | 2018 |
| Lubrenha Trading and Supplies Limited | Wholesale & retail | 2022 |
| Lucas Accommodation Ltd | Hospitality | 2022 |
| Lucas Go Ltd | Transport & logistics | 2025 |
| LUCATRANS95 Ltd | Transport & logistics | 2020 |
| Luchi Plumbing and Heating Limited | Construction | 2012 |
| Luck & Holness Ltd | Construction | 2020 |
| Lucky Hands Ltd | Wholesale & retail | 2013 |
| Lucolas-M.D. Ltd | Professional & scientific | 2010 |
| Lucy and the Horseman Foundation | Health & social care | 2015 |
| Lucylu Media Ltd | Professional & scientific | 2010 |
| Luke Hayes Photography Ltd | Professional & scientific | 2012 |
| Luke Sabourin Limited | Construction | 2024 |
| Lukeman Scott Consultants Limited | Professional & scientific | 2015 |
| Lukfak & Associates Ltd | Hospitality | 2022 |
| Lukfak Consulting Limited | Wholesale & retail | 2020 |
| Lullenden Estates Company Ltd | Construction | 2010 |
| Lumae London Ltd | Wholesale & retail | 2026 |
| Lumawear Limited | Wholesale & retail | 2008 |
| Lumbini Cuisine Ltd | Hospitality | 2024 |
| Lumen Fit-Out Ltd | Construction | 2024 |
| Lumen Human Resources Management Limited | Administrative & support | 2024 |
| Lumen Skin Clinic Ltd | Other services | 2019 |
| Lumenex Electrical Contractors Limited | Manufacturing | 2025 |
| Lumicez Ltd | Transport & logistics | 2025 |
| Luminary Motion Ltd | Information & communication | 2023 |
| Lumior Limited | Information & communication | 2025 |
| Lumora.Me Limited | Health & social care | 2025 |
| Lumsden Heights Limited | Real estate | 2025 |
| Luna KIN Ltd | Wholesale & retail | 2016 |
| Lupus Studios Limited | Information & communication | 2023 |
| Lurano Outdoor Living Ltd | Extraterritorial | 2026 |
| Lush Consultancy Services Limited | Professional & scientific | 2024 |
| Lush Records Ltd | Information & communication | 2020 |
| Lush Services Limited | Administrative & support | 2019 |
| Luvpretty Ltd | Wholesale & retail | 2024 |
| LUX Architectural Limited | Construction | 2021 |
| LUX Life Properties Ltd | Real estate | 2026 |
| Luxarium Ltd | Wholesale & retail | 2023 |
| Luxbnb Homes and Apartments Ltd | Hospitality | 2025 |
| Luxe Avenue Ltd | Wholesale & retail | 2025 |