| LEO GAS Inspection Limited | Construction | 2016 |
| LEO Interior Plastering Ltd | Construction | 2023 |
| LEO Marian Construct Ltd | Construction | 2025 |
| LEO Valeting Centre Ltd | Wholesale & retail | 2024 |
| Leo's Kitchen Limited | Hospitality | 2015 |
| Leon Engineering Limited | Administrative & support | 2014 |
| Leon Software Solutions Limited | Information & communication | 2012 |
| Leonandcoach Ltd | Transport & logistics | 2023 |
| Leopard Group Limited | Financial services | 2026 |
| Leor Construction Services Limited | Construction | 2024 |
| Leovision Ltd | Construction | 2016 |
| Leozluxury Ltd | Wholesale & retail | 2026 |
| Leporid Ltd | Information & communication | 2011 |
| LER Solutions Ltd | Information & communication | 2012 |
| Lesan Property Holdings Limited | Real estate | 2021 |
| Lesarf Limited | Construction | 2009 |
| Leskon Business Limited | Wholesale & retail | 2013 |
| Lessi Limited | Information & communication | 2013 |
| LET Flex Ltd | Real estate | 2023 |
| LET U Drive Ltd | Education | 2025 |
| LET US Buy Limited | Real estate | 2023 |
| Let's DO Drama! Limited | Education | 2025 |
| Letchworths Limited | Professional & scientific | 2005 |
| Lethal Movie Ltd | Information & communication | 2010 |
| Letir Ltd | Construction | 2015 |
| Lets ALL Find Love Ltd | Wholesale & retail | 2026 |
| Lets Care 4 Herts Ltd | Real estate | 2018 |
| Lettings Plus Property Consultants Ltd | Construction | 2014 |
| Lettings Plus Property Ltd | Real estate | 2024 |
| Lettings Plus Property Management Services Ltd | Real estate | 2011 |
| Letusbuild Property Limited | Real estate | 2024 |
| Lety Services Ltd | Construction | 2017 |
| LEV Gutfeld Limited | Real estate | 2016 |
| LEV Kornblum Limited | Real estate | 2017 |
| LEV Liverpool Ltd | Real estate | 2019 |
| LEV Lusco Limited | Real estate | 2016 |
| LEV Properties Investments Ltd | Real estate | 2021 |
| LEV Properties Limited | Real estate | 2016 |
| Levace Limited | Professional & scientific | 2010 |
| Levantine (UK) Limited | Manufacturing | 2002 |
| Levanto Ltd | Wholesale & retail | 2026 |
| Leve Mobility Ltd | Manufacturing | 2013 |
| Lever & Fulcrum Solutions Ltd | Information & communication | 2026 |
| Lever Capital Limited | Other services | 2018 |
| Levy Construct Ltd | Construction | 2019 |
| Lewai Ltd | Wholesale & retail | 2023 |
| Lewginken Limited | Information & communication | 2017 |
| Lewis Green Energy UK Ltd | Wholesale & retail | 2024 |
| Lewis Henry Twydle Limited | Hospitality | 2015 |
| Lewis Meehan Property Management Limited | Real estate | 2004 |
| LEX Chauffeur Ltd | Transport & logistics | 2025 |
| Lexan Skin Ltd | Wholesale & retail | 2025 |
| Lexham Gardens Freehold Limited | Real estate | 2009 |
| Lexica Limited | Information & communication | 1990 |
| Lexifi Limited | Professional & scientific | 2025 |
| Lexus Consultancy Ltd | Professional & scientific | 2012 |
| Lexus Legal Services & Consultancy Ltd | Other services | 2016 |
| Lexus Services Ltd | Financial services | 2015 |
| LF Building Services Ltd | Construction | 2012 |
| LF Property Developments Ltd | Real estate | 2023 |
| LG GAS Works Limited | Other services | 2014 |
| LGB Direct Limited | Wholesale & retail | 2010 |
| LGC Management & Consultancy Ltd | Real estate | 2019 |
| LGN Locum Ltd | Health & social care | 2025 |
| LH Civil Engineering Ltd | Construction | 2023 |
| Lh&E Cost Consultancy Ltd | Construction | 2020 |
| Lh&E Develop Limited | Real estate | 2024 |
| Lhabc Limited | Health & social care | 2010 |
| Lhenterprises Ltd | Wholesale & retail | 2018 |
| Liam Henry Limited | Professional & scientific | 2016 |
| Liandri Ltd. | Information & communication | 2016 |
| Liberati Property Ltd | Real estate | 2019 |
| Libero IT Trans Limited | Transport & logistics | 2018 |
| Liberty Music CIC | Arts & recreation | 2024 |
| Liberty Stowe Limited | Information & communication | 2016 |
| Liberty Walk Management Company Limited | Households | 2000 |
| Libra Enterprises Limited | Administrative & support | 2008 |
| Lichfield Place Management Company Limited | Households | 1989 |
| Lidar Library Ltd | Information & communication | 2023 |
| Lidar Lounge Ltd | Arts & recreation | 2014 |
| Lido Housewares Limited | Wholesale & retail | 2007 |
| Liebfrog Limited | Professional & scientific | 2015 |
| LIF Consulting Limited | Professional & scientific | 2024 |
| Lifan Ltd | Wholesale & retail | 2014 |
| Life FLY Limited | Wholesale & retail | 2022 |
| Life Ingredients LLP | | 2023 |
| Life Insurance Corporation of India | | 2023 |
| Life Sense Ltd | Other services | 2018 |
| Life Wave International Ltd | Administrative & support | 2023 |
| Lifecycle Designs Limited | Manufacturing | 2020 |
| Lifehealth Limited | Administrative & support | 1995 |
| Lifetime Corporate Finance Ltd | Financial services | 2008 |
| Lifeworkz Limited | Information & communication | 2020 |
| Lift Healthcare Ltd | Health & social care | 2025 |
| Lift-Off Global Network Limited | Information & communication | 2014 |
| Liftupebikes Ltd | Wholesale & retail | 2025 |
| Light Counsel Limited | Education | 2023 |
| Light Film Post Production Ltd | Information & communication | 2020 |
| Lightbook Limited | Manufacturing | 2017 |
| Lighten UP Limited | Construction | 2016 |