| Lainston Wealth Management Limited | Financial services | 2022 |
| Lakeside (T) Hairdressing Limited | Other services | 2025 |
| Laleham Health & Beauty Solutions Limited | Financial services | 1992 |
| Laleham Health and Beauty Limited | Manufacturing | 1970 |
| Land Inheritance Limited | Real estate | 2003 |
| Landscape Juice Limited | Administrative & support | 2013 |
| Landtourer Coaches Limited | Transport & logistics | 1984 |
| Lane Willis Holdings LLP | | 2015 |
| Laneside Building Services Limited | Construction | 2010 |
| Lansdowne House (Alton) Property Management Company Limited | Households | 2005 |
| Lansdowne House Alton Limited | Real estate | 2022 |
| Lanthano Limited | Real estate | 2010 |
| Lara Jane Ltd | Extraterritorial | 2016 |
| Lara Meyer Insights Ltd | Professional & scientific | 2021 |
| Larda Recipe Manager Ltd | Information & communication | 2025 |
| Largeacre Limited | Professional & scientific | 1988 |
| Larkshead Licensing Limited | Information & communication | 2016 |
| Laser Loft UK Limited | Other services | 2023 |
| Lasham Estates Limited | Administrative & support | 2000 |
| Lasham Farm Limited | Transport & logistics | 2026 |
| Lasham Vintage Gliding Club Limited | Arts & recreation | 2017 |
| Latch Fundraising Ltd | Administrative & support | 2023 |
| Laurel Services Ltd | Professional & scientific | 2025 |
| Lauterbach Limited | Manufacturing | 2001 |
| Lavington Publishing Limited | Information & communication | 2009 |
| Lawley Constructions Ltd | Hospitality | 2023 |
| LC Group Ltd | Real estate | 2025 |
| LE Roux Investments (2014) Limited | Professional & scientific | 2014 |
| Lead Brave Ltd | Administrative & support | 2023 |
| Leadenhall Advisory Partners Ltd | Professional & scientific | 2014 |
| Leading Edge Market Research Limited | Professional & scientific | 2021 |
| Leah and Rowbotham Limited | Wholesale & retail | 1986 |
| Leamington Spa (T) Hairdressing Limited | Other services | 1997 |
| Leaping Trout Ltd | Hospitality | 2003 |
| Leatherhead (T) Hairdressing Limited | Other services | 2018 |
| Leatherhead (T2) Hairdressing Limited | Other services | 2023 |
| Lechtal Global Limited | Professional & scientific | 2013 |
| Leeds Albion Place (T) Hairdressing Limited | Other services | 2013 |
| Legacy-Direct Aftercare Ltd | Professional & scientific | 2020 |
| Lehmann Services Ltd | Construction | 2025 |
| Leigh Property Investments Limited | Professional & scientific | 2003 |
| Leisuredyne Limited | Professional & scientific | 2000 |
| Leisuredyne Resources Limited | Administrative & support | 2022 |
| Leiter Solutions (UK) Limited | Information & communication | 2025 |
| Leith Properties Ltd | Real estate | 2022 |
| Lemon Stone Events Ltd | Hospitality | 2020 |
| Lennon's Legacy SPV Limited | Information & communication | 2018 |
| Lenton-Magor Ltd | Professional & scientific | 2026 |
| LER Electrical Solutions Ltd | Construction | 2022 |
| LET ME Go Limited | Information & communication | 2015 |
| Letfield Ltd | Real estate | 2011 |
| Levelstate Systems Limited | Manufacturing | 1990 |
| LEX 2023 Limited | Professional & scientific | 2023 |
| LFM Group Limited | Professional & scientific | 2026 |
| Liftmaster GE Limited | Wholesale & retail | 2020 |
| Liftmaster Limited | Manufacturing | 1985 |
| Lightfoot Tree Services Ltd | Agriculture & fishing | 2024 |
| Lighthouse Developments Limited | Construction | 1999 |
| Lighting Studio Ltd | Manufacturing | 2009 |
| Lilliummeon Gundogs Limited | Agriculture & fishing | 2025 |
| Lime Tree Nursery Limited | Health & social care | 2015 |
| Lina Medical Product Management Limited | Professional & scientific | 2022 |
| Linchpin Marketing Limited | Professional & scientific | 2001 |
| Lincoln (T2) Hairdressing Limited | Other services | 2013 |
| Linegar Properties Ltd | Real estate | 2021 |
| Lioncrest Consulting Ltd | Professional & scientific | 2018 |
| Literoof Solutions Ltd | Construction | 2020 |
| Little Fish Fabrication Ltd | Wholesale & retail | 2025 |
| Little Meadows Nursery Ltd | Education | 2022 |
| Little Oaks Enterprises Ltd | Professional & scientific | 2021 |
| Little YOU Limited | Manufacturing | 2019 |
| Livre Logistics Limited | Transport & logistics | 2021 |
| LIZ Ampairee P.R. Limited | Administrative & support | 2006 |
| LJS Consulting Services Limited | Information & communication | 2019 |
| LMS Trading Group Limited | Wholesale & retail | 2025 |
| Loadmasters Limited | Transport & logistics | 2004 |
| Logicx Ltd | Information & communication | 2025 |
| Lomax Athletiwear Ltd | Wholesale & retail | 2023 |
| London (T) Academy Limited | Other services | 2023 |
| London Dynamic B Ltd | Financial services | 2023 |
| Long Story Holdings Limited | Financial services | 2018 |
| Look and Find Limited | Real estate | 2007 |
| Louise Peacock Creative Studio Ltd | Arts & recreation | 2019 |
| Lovable Rogues Ltd | Other services | 2023 |
| Love Child Care Recruitment Ltd | Administrative & support | 2021 |
| Love My Halo Ltd | Wholesale & retail | 2020 |
| Love Recruitment Ltd | Administrative & support | 2014 |
| LPA Services Ltd | Professional & scientific | 2019 |
| LPJ Pathology Limited | Health & social care | 2024 |
| LPN Advisory Ltd | Professional & scientific | 2019 |
| LSA Secure Holdings Limited | Other services | 2021 |
| LSA Secure Limited | Administrative & support | 2015 |
| Luca Milano Limited | Wholesale & retail | 2025 |
| Luceon Ltd | Manufacturing | 2018 |
| Lucia Properties Limited | Professional & scientific | 2004 |
| Lucy Cares Limited | Other services | 2017 |
| Luke Cave (Watford) Limited | Other services | 2025 |
| Luna 22 Management Services Limited | Financial services | 2022 |
| Luxury House Share Limited | Real estate | 2011 |
| Luxury Waterside Lettings (Hythe) Ltd | Real estate | 2017 |