| Laser Vision Care Ltd | Health & social care | 2023 |
| Lasertech Limited | Manufacturing | 1997 |
| LATEDEVELOPER33 Ltd | Professional & scientific | 2024 |
| Laughlin Property Development Limited | Construction | 2009 |
| Laura Marsh Limited | Professional & scientific | 2012 |
| Laura Millar Home Finders Ltd | Real estate | 2023 |
| Lava Flow Solutions Limited | Manufacturing | 2022 |
| Lavender Electrical Limited | Construction | 2018 |
| Lavers & Company Limited | Construction | 1937 |
| Lavita Style Limited | Households | 2010 |
| Lawnculture Ltd | Administrative & support | 2017 |
| Lawson Crescent Limited | Wholesale & retail | 2022 |
| Laxmi Research and Healthcare Ltd | Health & social care | 2014 |
| Layham Road Ltd | Real estate | 2020 |
| LB Bathroom Renovation Ltd | Construction | 2025 |
| LBR17 Limited | Arts & recreation | 2025 |
| LC International Ltd | Construction | 2018 |
| Lci-Uk Limited | Other services | 2005 |
| Lci-Uk Projects Limited | Education | 2019 |
| Lcjm Limited | Professional & scientific | 2026 |
| LCM Construction and Design Ltd | Construction | 2022 |
| LD Media Productions Ltd | Professional & scientific | 2023 |
| LD Travel Ltd | Administrative & support | 2025 |
| LDA Compliance Ltd | Construction | 2025 |
| LDC Meats Limited | Wholesale & retail | 2014 |
| LDN Sales Ltd | Wholesale & retail | 2024 |
| Ldth Solutions Ltd | Manufacturing | 2022 |
| LDV7 Executive Chauffeurs Limited | Transport & logistics | 2020 |
| LE COQ AU Van Ltd | Hospitality | 2023 |
| LE Raisin D'Etre Ltd | Wholesale & retail | 2024 |
| Lead Real Estate Investments Limited | Real estate | 2019 |
| Leadership and Learning Limited | Professional & scientific | 2009 |
| Leading Edge Sport Limited | Professional & scientific | 2026 |
| Leading Lawyers Limited | Professional & scientific | 2020 |
| Leafcutter Studios Limited | Information & communication | 2009 |
| Leapforward.Ai Ltd | Financial services | 2024 |
| Learn by Play Ltd | Extraterritorial | 2023 |
| Learn EAT Play Limited | Health & social care | 2021 |
| Learn Norwegian Today Ltd. | Education | 2017 |
| LEE & SON Surfacing Limited | Construction | 2012 |
| LEE Menzies Limited | Arts & recreation | 1983 |
| LEE, Dicketts Limited | Administrative & support | 2006 |
| Legacy Park Homes Limited | Manufacturing | 2024 |
| Legal Sustainability Alliance | Other services | 2021 |
| Legendary Sports and Entertainment Ltd | Information & communication | 2010 |
| Legg & Co Property Limited | Real estate | 2012 |
| Legg & Co Property Maintenance Limited | Real estate | 2022 |
| Legin Systems Limited | Information & communication | 1985 |
| Lemon Lime Energy Limited | Energy | 2023 |
| LEO Sting Ltd | Wholesale & retail | 2020 |
| LEO the Baker Ltd | Manufacturing | 2025 |
| Lerici Holiday Holdings Ltd | Hospitality | 2023 |
| Lesoza Enterprises Limited | Professional & scientific | 2017 |
| Lets Help Property Management Services Ltd | Real estate | 2013 |
| Levantpitacrisps Ltd | Manufacturing | 2025 |
| Level 36 Ltd | Professional & scientific | 2024 |
| Leverets Advisory Limited | Professional & scientific | 2021 |
| Leverets Alternative Dispute Resolution Limited | Professional & scientific | 2021 |
| Leverets Environmental Sustainable Governance Limited | Professional & scientific | 2021 |
| Leverets Group Limited | Financial services | 2025 |
| Levick Plumbing & Heating Ltd | Construction | 2018 |
| Lewis Estates (Wolverhampton) Limited | Construction | 1955 |
| Lewisham Properties LLP | | 2020 |
| Lewy Limited | Real estate | 2017 |
| Leximar Limited | Professional & scientific | 2018 |
| Leys Properties Limited | Real estate | 2024 |
| LGN Sevenoaks Ltd | Real estate | 2025 |
| Liana Weatherhead Consultancy Ltd | Professional & scientific | 2022 |
| Liberty Scaffolding Limited | Administrative & support | 2008 |
| Liberty Transportation and Logistics Ltd | Wholesale & retail | 2018 |
| Lichfield Spires Development Limited | Construction | 2021 |
| Life 360 Health Limited | Health & social care | 2025 |
| Life in Order Ltd | Information & communication | 2026 |
| Lifespan Nutrition Ltd | Health & social care | 2020 |
| Light LDN Limited | Wholesale & retail | 2015 |
| Lighthouse Learning & Consultancy Ltd | Health & social care | 2025 |
| Lightness Consulting UK Limited | Professional & scientific | 2025 |
| Lightning School of Gymnastics Limited | Arts & recreation | 2017 |
| Lightwork Group Limited | Administrative & support | 2002 |
| Lightwork Magazine Ltd | Manufacturing | 2020 |
| Lightwork Studios Ltd | Professional & scientific | 2020 |
| Lilia's Kitchen Ltd | Hospitality | 2016 |
| Lilyoaks Psychological and Counselling Practice Ltd | Education | 2026 |
| Lime Tree Capital Limited | Real estate | 2021 |
| Limegate Group Limited | Construction | 2016 |
| Limegate Ltd | Professional & scientific | 2013 |
| Limegate Solutions Ltd | Construction | 2017 |
| Limetree Mews Management Co Ltd | Administrative & support | 2007 |
| Liminal Connections Ltd | Health & social care | 2022 |
| Limitless Flow Ltd | Professional & scientific | 2021 |
| LIN Properties (Service) Limited | Real estate | 1967 |
| Lincoln Properties Limited | Real estate | 1986 |
| Lincolnshire Property Centre Limited | Real estate | 2020 |
| Linden Catering Ltd | Hospitality | 2020 |
| Linden Chase Residents Limited | Households | 2004 |
| Linden Glen Management Limited | Households | 1987 |
| Linden Square Management Co. Limited | Households | 1990 |
| Lindesay Properties Ltd | Real estate | 2023 |
| Linelive Limited | Professional & scientific | 1989 |
| Ling Associates Ltd | Wholesale & retail | 2026 |