| Lsmp and TLS PCN Limited | Health & social care | 2023 |
| Lspropertyuk Limited | Construction | 2023 |
| LSR Training and Development Ltd. | Education | 2013 |
| Lsraw Grooming&Accessories Ltd | Wholesale & retail | 2022 |
| Lsrentalsuk Ltd | Real estate | 2024 |
| Lstwenty Five Limited | Administrative & support | 2023 |
| Lsvr Consulting Ltd | Professional & scientific | 2026 |
| LSW Properties (Morley) Limited | Construction | 2025 |
| LT Consultancy Group Ltd | Other services | 2025 |
| LT Doria Ltd | Health & social care | 2020 |
| LT Grey Ltd | Information & communication | 2023 |
| LT Medical & Value Communications Ltd | Professional & scientific | 2019 |
| LTB Carpentry Ltd | Manufacturing | 2025 |
| LTC25 Limited | Financial services | 2020 |
| Ltd & Co. Holding Ltd | Wholesale & retail | 2026 |
| Ltd (Hebden Bridge) Limited | Wholesale & retail | 2012 |
| Ltd Tyres Recycling Limited | Water & waste | 2023 |
| LTH (Kent) Limited | Transport & logistics | 2007 |
| LTM Leeds Travel Group Limited | Administrative & support | 2018 |
| LTM Motors Limited | Wholesale & retail | 2015 |
| LTT Group Limited | Professional & scientific | 2025 |
| LTT Vending Group Limited | Professional & scientific | 1995 |
| LTT Vending Ltd | Extraterritorial | 1962 |
| LTU13 Ltd | Wholesale & retail | 2018 |
| LTW Landscapes Ltd | Administrative & support | 2025 |
| LU Luxe Limited | Manufacturing | 2025 |
| Luan Limited | Health & social care | 2005 |
| Lubelo Ltd | Extraterritorial | 2023 |
| Luben Glass UK Ltd | Manufacturing | 2019 |
| Lubert School of Music London Ltd | Education | 2024 |
| Lubetec UK Limited | Manufacturing | 2004 |
| Luby International Air Cargo Ltd | Transport & logistics | 2026 |
| Luc.K Direct Ltd | Transport & logistics | 2017 |
| Luca Acquisitions Ltd | Real estate | 2022 |
| Luca Capital Limited | Information & communication | 2020 |
| Lucas Housing Ltd | Real estate | 2024 |
| Lucas Media Ltd | Information & communication | 2017 |
| Lucas Supreme Freight Ltd | Transport & logistics | 2025 |
| Lucasam Data Services Ltd | Information & communication | 2023 |
| Lucava DEV3 Ltd | Real estate | 2020 |
| Lucava Developments Ltd | Real estate | 2013 |
| Luce's Bakery Ltd | Manufacturing | 2024 |
| Lucella Consulting Limited | Extraterritorial | 2014 |
| Lucent Digital Studio Ltd. | Wholesale & retail | 2024 |
| Lucent Glazing Ltd | Construction | 2025 |
| Lucianos Pizza & Chinese Ltd | Hospitality | 2025 |
| Lucianos Pizza House Ltd | Hospitality | 2026 |
| Lucid Accountants Limited | Professional & scientific | 2007 |
| Lucid Data Solutions Ltd | Information & communication | 2021 |
| Lucid Electrical Services Ltd | Construction | 2015 |
| Lucid GEM Group Ltd | Construction | 2025 |
| Lucidnexa Limited | Information & communication | 2025 |
| Lucis Holdings Limited | Financial services | 2016 |
| Lucis Pharma Ltd | Wholesale & retail | 2012 |
| Luckgren Company Limited | Health & social care | 2012 |
| Lucky Girl Syndrome Ltd | Wholesale & retail | 2023 |
| Lucky Grace Ltd | Hospitality | 2026 |
| Lucky H&G Ltd | Hospitality | 2021 |
| Lucky North Ltd | Professional & scientific | 2019 |
| Lucky Panda (1AU) Ltd | Hospitality | 2023 |
| Lucky Star 518 Ltd | Hospitality | 2019 |
| Luckys Couriers Ltd | Transport & logistics | 2020 |
| Luckys Hospitality Limited | Hospitality | 2019 |
| Luckyz Property Services Ltd | Administrative & support | 2025 |
| Lucrative Passion Limited | Financial services | 2025 |
| Lucy Bennett EAR WAX Removal Specialist Ltd | Health & social care | 2026 |
| Lucy Guest Marketing Limited | Professional & scientific | 2021 |
| Lucy Sherman Limited | Administrative & support | 2005 |
| Ludgate Construction Limited | Construction | 2021 |
| Ludgate Project Solutions Ltd | Construction | 2019 |
| Ludium Music Ltd | Wholesale & retail | 2025 |
| Ludopunks Ltd | Manufacturing | 2023 |
| Luis Romao Limited | Information & communication | 2016 |
| Luka Solutions Ltd | Other services | 2024 |
| Lukasz LIM Ltd | Transport & logistics | 2024 |
| Lukasz SUS Limited | Transport & logistics | 2018 |
| Lukat Property Ltd | Real estate | 2024 |
| Luke Gale Limited | Real estate | 2017 |
| Luke Hughes & Company Limited | Manufacturing | 1985 |
| Luke James Content Marketing Ltd | Professional & scientific | 2021 |
| Luke Robinson Brickwork Limited | Construction | 2025 |
| LUKEGRIFFIN91 Ltd | Transport & logistics | 2025 |
| Luli Delicieux Maison Ltd | Wholesale & retail | 2025 |
| Lulix Consulting Ltd | Professional & scientific | 2025 |
| Lullaslight Ltd | Manufacturing | 2024 |
| Luma Health Group Ltd | Information & communication | 2026 |
| Lumby Garden Centre Limited | Wholesale & retail | 2022 |
| Lumby Hall Farm Management Company Limited | Households | 2023 |
| Lumby Homes Ltd | Real estate | 2025 |
| Lumby’S Auto LAB Ltd | Wholesale & retail | 2026 |
| Lume Flow Limited | Other services | 2026 |
| Lume Holdings Ltd | Financial services | 2025 |
| Lumen Arts | Arts & recreation | 2001 |
| Lumen Commerce Limited | Professional & scientific | 2025 |
| Lumen Global UK Limited | Financial services | 2022 |
| Lumenveil Ltd | Information & communication | 2025 |
| Lumera Fine Jewellery Ltd | Wholesale & retail | 2026 |
| Lumi & Lumiere Limited | Professional & scientific | 2024 |
| Lumiadd Ltd | Manufacturing | 2022 |
| Lumicommerce Limited | Wholesale & retail | 2024 |