| London City Living Limited | Real estate | 2013 |
| London Interiors Studio & Design Ltd | Professional & scientific | 2023 |
| London Interiors Studio Limited | Financial services | 2022 |
| London Living Ltd. | Administrative & support | 2015 |
| London Road Pharma Limited | Wholesale & retail | 2024 |
| London Summer School Events Limited | Administrative & support | 2014 |
| Londonmia Woman Ltd | Wholesale & retail | 2023 |
| Long Acre Farm (Storage) Limited | Transport & logistics | 2021 |
| Long Copse Court (Management) Co. Limited | Hospitality | 1973 |
| Longcross Properties Limited | Construction | 1998 |
| Longmead Langstone (Flat Management) Company Limited | Households | 1974 |
| Lontor Limited | Health & social care | 2022 |
| Loopstrand Limited | Professional & scientific | 2026 |
| Loquiwell Ltd | Professional & scientific | 2026 |
| Lorw Investments Limited | Real estate | 2018 |
| Lorw Limited | Professional & scientific | 2016 |
| Losh Software Limited | Information & communication | 2019 |
| LOT Investments Limited | Professional & scientific | 2018 |
| Lotus Cosmetic DOC Limited | Health & social care | 2014 |
| Lotus Swan Limited | Hospitality | 2011 |
| Lou's Carpet Tiles Limited | Wholesale & retail | 2017 |
| Louandmariacoffeequaters Ltd | Hospitality | 2025 |
| Loudandclearcommunications Ltd | Public administration | 2025 |
| Love Air BNB Ltd | Hospitality | 2019 |
| Love Copnor Limited | Arts & recreation | 2017 |
| Love Potion Clothing Ltd | Wholesale & retail | 2024 |
| Love Your Football Club Limited | Arts & recreation | 2025 |
| Lovedean Medical Limited | Health & social care | 2018 |
| Loveless & Co Accountants Ltd | Professional & scientific | 2014 |
| Lovely Chops Ltd | Other services | 2017 |
| Lovesouthsea Limited | Information & communication | 2012 |
| LOW Cost Beauty Limited | Wholesale & retail | 2020 |
| Lower Drayton Lane Ltd | Households | 2006 |
| Lower Ponds Management Limited | Real estate | 2026 |
| Lowercase 25 Limited | Professional & scientific | 2026 |
| Lowercase Cardiff Limited | Administrative & support | 2014 |
| Lowercase Live Limited | Arts & recreation | 2025 |
| Lowercase Marketing Limited | Administrative & support | 2014 |
| Lowercase Midlands Limited | Administrative & support | 2014 |
| Loxley Food Service Ltd. | Wholesale & retail | 2013 |
| Loyal Insurance Services Ltd | Administrative & support | 2005 |
| Loyalmanor Properties Limited | Real estate | 1990 |
| LPH Homes Ltd | Real estate | 2024 |
| LR8 RTM Company Limited | Households | 2015 |
| LRS Property Lets Ltd | Real estate | 2025 |
| LS Drive Ltd | Transport & logistics | 2018 |
| LS Leisure Limited | Construction | 2017 |
| LS Pre-School Limited | Education | 2012 |
| Lscarpentry Ltd | Construction | 2020 |
| Lsjr Properties Limited | Real estate | 2016 |
| LSS Garments Ltd | Wholesale & retail | 2026 |
| LST Trans Ltd | Transport & logistics | 2020 |
| Ltd Investments Limited | Financial services | 2021 |
| Lucian Toader Limited | Construction | 2015 |
| Lucknow Central Ltd | Hospitality | 2025 |
| Lucky Accountants Ltd | Professional & scientific | 2020 |
| Lucky Choice Ltd | Wholesale & retail | 2024 |
| Lucky Seven Investments Ltd | Financial services | 2026 |
| Lucrin Investment Ltd | Financial services | 2025 |
| Lucrin Property Ltd | Real estate | 2023 |
| Lucy Goodale Consultancy Ltd | Administrative & support | 2018 |
| Luji Events Limited | Hospitality | 2024 |
| Luji Ltd | Hospitality | 2021 |
| Luker-Arts Studio Ltd | Wholesale & retail | 2026 |
| Luma Mechanical & Electrical Ltd | Construction | 2025 |
| Lumia Audio Visual Ltd | Information & communication | 2019 |
| Lumia Enterprises Ltd | Construction | 2026 |
| Lumin Partners Ltd | Professional & scientific | 2023 |
| Lumivon Limited | Manufacturing | 2026 |
| Luna Laser Ltd | Other services | 2025 |
| Luscious Breaks Limited | Administrative & support | 2025 |
| Lush Bite 2 Limited | Hospitality | 2026 |
| Lush Clothing Limited | Wholesale & retail | 2024 |
| Lush Nails Portsmouth Ltd | Other services | 2025 |
| Lushbites Ltd | Hospitality | 2025 |
| Lusid London Ltd | Administrative & support | 2018 |
| Lustra Bathrooms Ltd | Construction | 2024 |
| Lustra Installs Ltd | Construction | 2023 |
| Lustre Surfaces Treatments Limited | Professional & scientific | 1996 |
| Luthan Property Services Ltd | Construction | 2016 |
| LUX Alliance Limited | Manufacturing | 2025 |
| Luxe Carpentry Ltd | Manufacturing | 2024 |
| Luxe Gold Trading Ltd | Other services | 2025 |
| Luxe Lash Co London Limited | Other services | 2019 |
| Luxe Space Homes Ltd | Real estate | 2018 |
| Luxe Veritas Ltd | Wholesale & retail | 2024 |
| Luxestates Group Ltd | Real estate | 2026 |
| Luxis Media Solutions Limited | Construction | 2013 |
| Luxurious Living Ltd | Wholesale & retail | 2019 |
| Lycol Training Services Limited | Professional & scientific | 2005 |
| Lydcott Developments Limited | Construction | 2023 |
| Lydney Developments Limited | Real estate | 2023 |
| Lyminster Court Limited | Real estate | 2023 |
| Lynch Mechanical, Plumbing & Heating Ltd | Construction | 2022 |
| Lynches Limited | Real estate | 2023 |
| Lynken Leisure Limited | Hospitality | 2019 |
| Lynton Grove Properties Limited | Real estate | 2026 |
| Lynx Car Storage Limited | Transport & logistics | 2025 |
| Lynx Roofing Ltd | Construction | 2020 |
| Lyons F Holdings Ltd | Financial services | 2025 |