| Lambert Electrical Ltd | Construction | 2025 |
| Lambourne Poole Associates Ltd | Information & communication | 2014 |
| Lamm Property Holdings Limited | Real estate | 2020 |
| Lamp and Pencil Ltd | Manufacturing | 2014 |
| Land West Old Mead Management Ltd | Households | 2026 |
| Landflex Containment Solutions Limited | Extraterritorial | 2014 |
| Landflex Geosynthetics Limited | Extraterritorial | 1998 |
| Lane Group (Holdings) Limited | Professional & scientific | 2018 |
| Lanexpress Ltd | Wholesale & retail | 2023 |
| Langlands (Manuden) Limited | Real estate | 2013 |
| Larsen Properties Ltd | Real estate | 2022 |
| Laser Muse Limited | Other services | 2023 |
| Lasertag 2U Limited | Arts & recreation | 2023 |
| Latchmead BED and Breakfast Ltd | Hospitality | 2025 |
| Lateral Recruitment Ltd | Administrative & support | 2025 |
| Laura Kaye Studio Limited | Professional & scientific | 2025 |
| Laura SEE London Limited | Manufacturing | 2020 |
| Lavender Grange (Stondon) Residential Management Company Limited | Households | 2020 |
| Law Lead Ltd | Information & communication | 2023 |
| Lawbrook Holdings Ltd | Financial services | 2021 |
| Lawcatz Ltd | Information & communication | 2017 |
| Lawn Padel Ltd | Professional & scientific | 2026 |
| Lawrence Brothers (Wood Green) Limited | Extraterritorial | 1960 |
| Layer Consulting Ltd | Professional & scientific | 2024 |
| LBA Supplies Limited | Wholesale & retail | 2023 |
| Lblt Global Freight Ltd | Transport & logistics | 2021 |
| LBT PV Solutions Limited | Professional & scientific | 2010 |
| LD Storm Ltd | Wholesale & retail | 2025 |
| LDN Locations Ltd | Information & communication | 2022 |
| LDS Engineering Limited | Construction | 2010 |
| LE RAJ Stortford Limited | Hospitality | 2011 |
| LEA Hall Management Company Limited | Households | 2025 |
| Leach Homes Ltd | Construction | 2022 |
| Leading Plant Services Limited | Manufacturing | 2023 |
| Leaf Spice Limited | Hospitality | 2019 |
| Leafy Hill Ltd | Real estate | 2021 |
| Leao Ltd | Wholesale & retail | 2024 |
| Leap and Learn Sports Ltd | Education | 2025 |
| Learn Solutions Limited | Education | 2004 |
| Leasing Plus Ltd | Wholesale & retail | 2018 |
| Lecragate Properties Limited | Real estate | 1975 |
| Leda Aesthetics Ltd | Health & social care | 2024 |
| Lednor and Company Limited | Real estate | 2014 |
| LEE Consultancy Ltd | Professional & scientific | 2021 |
| LEE Lifestyle Ltd | Construction | 2008 |
| LEE Matthews Transport Limited | Transport & logistics | 2007 |
| Legal Check Services Ltd | Administrative & support | 2023 |
| Legal Robot Limited | Extraterritorial | 2017 |
| Legend Films UK Ltd | Wholesale & retail | 2024 |
| Lei's Information Technology Service Limited | Information & communication | 2018 |
| Leigh Keates Limited | Other services | 2017 |
| Lejend Consultancy Services Ltd | Real estate | 2019 |
| Lemans Real Estate Ltd | Real estate | 2019 |
| Lemon Squeezy Marketing Ltd | Professional & scientific | 2023 |
| Lemskah Limited | Administrative & support | 2005 |
| Leon Finances Limited | Financial services | 2024 |
| Leonid Group Consulting Services Ltd | Professional & scientific | 2026 |
| Leonid Group Corporate Governance Ltd | Administrative & support | 2020 |
| Leonid Group Innovation Incentives Ltd | Administrative & support | 2022 |
| Leonid Group Ltd | Administrative & support | 2018 |
| Leroco Ltd | Real estate | 2020 |
| LES Employees Trustees Limited | Extraterritorial | 2021 |
| LES Residence Falcon Wharf Limited | Real estate | 2007 |
| Letting Inventory Company Ltd | Real estate | 2014 |
| Levelline Tiling Limited | Construction | 2025 |
| Lever & Co. Legal Limited | Professional & scientific | 2023 |
| Lewis Consulting Limited | Professional & scientific | 2026 |
| Lewis Yates Limited | Wholesale & retail | 2008 |
| Lexden Limited | Professional & scientific | 2007 |
| LGC Shopfit Limited | Construction | 2023 |
| LGT Estate Agents Ltd | Real estate | 2023 |
| LGV Properties Ltd | Real estate | 2023 |
| Liberty the Agency Ltd | Other services | 2022 |
| Libris Digital Ltd | Information & communication | 2021 |
| Libris Systems Limited | Information & communication | 2016 |
| Life Environmental Group Limited | Administrative & support | 2007 |
| Life Environmental Services Limited | Professional & scientific | 1995 |
| Life Fire Services Limited | Professional & scientific | 2025 |
| Life IFA Ltd | Financial services | 2025 |
| Life Safety Engineering Ltd | Construction | 2026 |
| Lifeworkz Space Limited | Real estate | 2021 |
| Light Therapy Ltd | Administrative & support | 2017 |
| Lily Blake Ltd | Professional & scientific | 2025 |
| Lincoln & Katie Company Ltd | Hospitality | 2022 |
| Lincon Batteries Limited | Manufacturing | 1999 |
| Lindy Fenech Transformation Solutions Ltd | Professional & scientific | 2024 |
| Linkostar Ltd | Administrative & support | 2024 |
| Linkwell Limited | Households | 1984 |
| Liora Solis Ltd | Health & social care | 2025 |
| Lipvid Ltd | Information & communication | 2020 |
| Lisa Burns Design Limited | Professional & scientific | 2021 |
| Lissy Puig Limited | Other services | 2018 |
| List Ecom 1 Ltd | Wholesale & retail | 2026 |
| Liston Trading Company Limited | Construction | 2015 |
| Lithuanian Culture and Education Centre Lutute CIC | Education | 2026 |
| Little Bee's Day Nursery Limited | Health & social care | 2020 |
| Little Boots Bookstore Ltd | Wholesale & retail | 2025 |
| Little Oaks E18 Limited | Health & social care | 2019 |
| Livermore Consulting Ltd | Construction | 2022 |
| Living Space Homes Limited | Construction | 2018 |