| LCL Group Holdings Limited | Financial services | 2025 |
| LCO Energy Solutions Ltd | Construction | 2024 |
| Lcomps Ltd | Arts & recreation | 2024 |
| Lcon Health Ltd | Other services | 2025 |
| Lcon's Property Investments Limited | Real estate | 2023 |
| LCR Brandworks Ltd | Professional & scientific | 2024 |
| LDB Valeting Ltd | Administrative & support | 2014 |
| LDN Futures Ltd | Education | 2019 |
| LDT Carpentry Limited | Manufacturing | 2024 |
| Lead Edge Services Ltd | Administrative & support | 2015 |
| Leaf and Frosty Ltd | Manufacturing | 2024 |
| Leaf IT to US (Tree Specialists) Ltd | Other services | 2026 |
| Leamington Sight & Sound Limited | Construction | 1998 |
| Lease Logic Consultants Ltd | Financial services | 2011 |
| Legend Property Services Limited | Real estate | 2003 |
| Legends Hair and Beauty Limited | Administrative & support | 2018 |
| Legionella Consultancy Services Ltd | Water & waste | 2009 |
| Lenity Group Limited | Health & social care | 2020 |
| Lenity Information Services Ltd | Information & communication | 2023 |
| Leproperty Ltd | Real estate | 2021 |
| Lesleychudson Ltd | Health & social care | 2012 |
| Lestal Kenilworth Limited | Wholesale & retail | 2016 |
| LET the Music Play Ltd | Arts & recreation | 2023 |
| Levain and Cherry Coffee Hub Limited | Wholesale & retail | 2024 |
| Level Property Ltd | Real estate | 2026 |
| Lewen Capital Limited | Financial services | 2026 |
| Lexon (UK) Limited | Wholesale & retail | 1995 |
| Lexon UK Holdings Limited | Wholesale & retail | 2018 |
| LEY Builders Limited | Administrative & support | 2011 |
| LIA Healthcare Ltd | Health & social care | 2026 |
| Liaison Financial Services Limited | Financial services | 2007 |
| Liaison Investments Limited | Construction | 1991 |
| Liaison One Call Limited | Administrative & support | 2012 |
| Liaison Technology Limited | Administrative & support | 2014 |
| Liaison VAT Consultancy Limited | Professional & scientific | 1988 |
| Liberia Timber Marketing Limited | Administrative & support | 2011 |
| Liberty Genesis Ltd | Agriculture & fishing | 2019 |
| Liberty Holdings Shirley Ltd | Real estate | 2022 |
| Liberty Leisure Centres Ltd | Arts & recreation | 2014 |
| Librae Eleven Limited | Extraterritorial | 2025 |
| Librae One Ltd | Information & communication | 2012 |
| Librae SIX Ltd | Extraterritorial | 2013 |
| Librae TEN Limited | Extraterritorial | 2020 |
| Libre Diabetic Clinical Study Ltd | Health & social care | 2019 |
| Lifespan Neuropsychology Limited | Health & social care | 2022 |
| Lifestyle Concierge Requests Ltd | Wholesale & retail | 2015 |
| Lift Physiotherapy Ltd | Health & social care | 2023 |
| Lift RIP (UK) Limited | Construction | 2018 |
| Lifting Equipment Store Limited | Transport & logistics | 2017 |
| LIGHT2SITE Limited | Financial services | 2021 |
| Lightcoms Limited | Administrative & support | 2007 |
| Lightelligent Limited | Manufacturing | 2024 |
| Lighthouse Glass Limited | Education | 2014 |
| Lighting Consultants Limited | Professional & scientific | 2011 |
| Lightsoutusa Limited | Extraterritorial | 2016 |
| Lightswood Financial Limited | Financial services | 2018 |
| Lillie G Limited | Manufacturing | 1988 |
| Lily Bids Auction House Ltd | Wholesale & retail | 2025 |
| Lily-Beau London Limited | Wholesale & retail | 2015 |
| Lilyswagginwalks Ltd | Agriculture & fishing | 2025 |
| Lilywood Limited | Information & communication | 2012 |
| Lime Retail Metalwork Ltd | Manufacturing | 2013 |
| Limitless Potential Global Limited | Professional & scientific | 2022 |
| Linc Products and Services Limited | Transport & logistics | 2016 |
| Linda Allsopp Healthcare Consultancy Ltd | Health & social care | 2021 |
| Link Solutions Midlands Limited | Administrative & support | 2022 |
| Link Stadium Seating Limited | Manufacturing | 2018 |
| Linken Services Ltd | Construction | 2015 |
| Linkway Express Ltd | Transport & logistics | 2026 |
| Linread Limited | Manufacturing | 1925 |
| Lion Share Consultancy Limited | Professional & scientific | 2022 |
| Lioness Girls Football Ltd | Education | 2021 |
| Liquasil Ltd | Construction | 2013 |
| Littlands Ltd | Real estate | 2024 |
| Little Angels Nursery UK Limited | Education | 2006 |
| Little Blue Partners Limited | Administrative & support | 2026 |
| Little Explorers Hopwood Limited | Health & social care | 2014 |
| Little India (Astwood) Limited | Hospitality | 2016 |
| Little John's Lets Ltd | Financial services | 2018 |
| Little London Leisure Limited | Arts & recreation | 2004 |
| Little MAN Solutions Limited | Information & communication | 2005 |
| Little Shed Music Ltd | Arts & recreation | 2023 |
| Littleu Preschool Ltd | Health & social care | 2021 |
| Livettv Limited | Wholesale & retail | 2016 |
| Living for the Weekend Limited | Arts & recreation | 2017 |
| Livs Pretty Paws Limited | Other services | 2021 |
| Ljkc Limited | Real estate | 2013 |
| Ljsd Limited | Arts & recreation | 2020 |
| LLJ Heating Ltd | Construction | 2024 |
| LLJ Homes Ltd | Construction | 2023 |
| LLK Limited | Administrative & support | 2016 |
| Lloyd Contractors Limited | Construction | 2011 |
| Lloyds Mower Service Limited | Other services | 2024 |
| Lloyds Property Investments Limited | Construction | 2003 |
| LM Construction Holdings Ltd | Financial services | 2026 |
| Lm&D Ltd | Construction | 2019 |
| Local Store Redditch Ltd | Wholesale & retail | 2025 |
| Locatio Limited | Real estate | 2015 |
| Loch and Land Limited | Real estate | 2025 |
| Lockdown Medical Limited | Manufacturing | 2008 |