| Lionsgate Communications Limited | Professional & scientific | 2011 |
| Liquid Listening | Health & social care | 2010 |
| Liquor Lane Ltd | Wholesale & retail | 2025 |
| LIS UK (Brightlight) Productions Limited | Information & communication | 2025 |
| Lisa Whiting Aesthetics Ltd | Health & social care | 2019 |
| Lithium Solutions Limited | Information & communication | 2026 |
| Litho Services Ltd | Information & communication | 2011 |
| Little Acre (Hurst) Management Company Limited | Households | 2024 |
| Little Orchard Advisory Limited | Professional & scientific | 2022 |
| Little Organised Ltd | Wholesale & retail | 2023 |
| Little Parcel Ltd | Wholesale & retail | 2026 |
| Little Teddy's Loft Limited | Wholesale & retail | 2019 |
| Littleleaperspartyandplay Ltd | Arts & recreation | 2025 |
| Live 2 Design Ltd | Professional & scientific | 2022 |
| Live Consulting Ltd | Administrative & support | 2020 |
| Livechange Limited | Professional & scientific | 2006 |
| Livewithme Ltd | Information & communication | 2022 |
| Liyaisha Ltd | Wholesale & retail | 2026 |
| LK Trading UKI Ltd | Wholesale & retail | 2022 |
| Llanden Ltd | Construction | 2023 |
| LLE Holdings Ltd | Construction | 2025 |
| LM Retailer Limited | Wholesale & retail | 2024 |
| Lnkv Ltd | Real estate | 2024 |
| LO Bros. IP (UK) Limited | Administrative & support | 2018 |
| Lobsand Productions Limited | Information & communication | 2014 |
| LOC I.T. Solutions Limited | Information & communication | 2011 |
| Local Area Ltd | Information & communication | 2021 |
| Local Pathways C.I.C. | Health & social care | 2024 |
| Locarous Ltd | Information & communication | 2019 |
| Locations Filming Limited | Administrative & support | 2012 |
| Locations Mortgage Solutions Ltd | Financial services | 2019 |
| Locatum Limited | Information & communication | 2020 |
| Lockdown Projections Ltd | Arts & recreation | 2023 |
| LOD ERP Ltd | Information & communication | 2023 |
| Loddon Car Deals Limited | Wholesale & retail | 2020 |
| Loddon Cars Limited | Transport & logistics | 2014 |
| Loddon Homes Limited | Real estate | 2014 |
| Loddon Mill Estate Management Company Limited | Households | 1999 |
| Loddon Property Developments Limited | Construction | 2021 |
| Loft Link Limited | Construction | 2018 |
| Logic Wave Ltd | Information & communication | 2003 |
| Logical Logistics and Transport Limited | Other services | 2014 |
| Logik Ceilings & Partitioning Limited | Construction | 2011 |
| Logistics Ecommerce Limited | Professional & scientific | 2023 |
| Logo Printing Limited | Professional & scientific | 2021 |
| Lola Beck Limited | Financial services | 2022 |
| Lolly RAY Ltd | Manufacturing | 2022 |
| Lomond.Ai Ltd | Professional & scientific | 2025 |
| London Corporate Legal Limited | Professional & scientific | 2012 |
| London Finder Limited | Real estate | 2000 |
| London Hindu Aikyavedi | Other services | 2015 |
| London Plastic Centre Ltd | Other services | 2025 |
| London Road Beauty Ltd | Other services | 2015 |
| Lonewolf Grips UK Limited | Information & communication | 2020 |
| Long Xuan Limited | Hospitality | 2018 |
| Longdown Lodge (Management) Company Limited | Households | 2003 |
| Longmoor Eco Tech Ltd | Construction | 2025 |
| Looma Limited | Information & communication | 2020 |
| Lord-Brother Asset Consultancy Limited | Professional & scientific | 2025 |
| Lorescape Ltd | Manufacturing | 2009 |
| Lorne Court (Chalvey) Limited | Households | 1981 |
| Losehill Property Limited | Real estate | 2019 |
| Loso Solutions Limited | Professional & scientific | 2021 |
| Lotus IT Consultancy Limited | Information & communication | 2022 |
| Lotus Roots Ltd | Wholesale & retail | 2024 |
| Lotus Strategy Limited | Professional & scientific | 2019 |
| Louisa B Events Ltd | Hospitality | 2025 |
| Louveciennes Limited | Professional & scientific | 2011 |
| Love Kombucha Limited | Manufacturing | 2013 |
| Love Life and Ride Ltd | Wholesale & retail | 2017 |
| Lovecrafts Group Limited | Wholesale & retail | 2010 |
| Lovecrafts Makers Limited | Wholesale & retail | 2012 |
| Loveday Property Co Ltd | Real estate | 2019 |
| Lovelock Roofing Ltd | Construction | 2022 |
| Lovetattoos Limited | Other services | 2023 |
| Lowbeck Group Limited | Professional & scientific | 2007 |
| Lowbrook Electrical Ltd | Construction | 2016 |
| LPT Limited | Information & communication | 2012 |
| LS GAS and Heating Limited | Construction | 2012 |
| LSC Therapy Limited | Other services | 2022 |
| Lsjt Consulting Limited | Information & communication | 2022 |
| LT Boats Limited | Other services | 2019 |
| Lucent Diamonds Ltd | Wholesale & retail | 2026 |
| Lucenz Atelier Ltd | Wholesale & retail | 2025 |
| Lucibook Ltd | Information & communication | 2024 |
| Lucky Inc Limited | Wholesale & retail | 2024 |
| Lucky Stars Property Ltd | Real estate | 2023 |
| Luff Holdings Limited | Real estate | 1997 |
| Lukla International Limited | Wholesale & retail | 2023 |
| Lumera AI Limited | Information & communication | 2025 |
| Lumiere Films Ltd. | Information & communication | 2019 |
| Lumina Energy Limited | Construction | 2024 |
| Lumiqa Ltd | Professional & scientific | 2023 |
| Lunar Recruitment Group Limited | Administrative & support | 2023 |
| Luxe Group Ltd | Professional & scientific | 2025 |
| Luxit Ltd. | Professional & scientific | 2011 |
| Lydstone Limited | Professional & scientific | 2011 |
| Lyngfields Management Company Limited | Households | 2000 |
| Lynk Engineering Limited | Manufacturing | 1998 |
| Lynmouth Court Residents Association Limited | Households | 1986 |