| Lambourn Estate Limited | Financial services | 2022 |
| Landare Homes Limited | Construction | 1972 |
| Landare Investments Limited | Construction | 1963 |
| Landbeck Limited | Construction | 2024 |
| Landfell Limited | Extraterritorial | 2026 |
| Landtone Limited | Extraterritorial | 2025 |
| Lapton Consultants Limited | Construction | 1998 |
| Larrett Sports Limited | Extraterritorial | 1977 |
| Laser LAB Wales Ltd | Manufacturing | 2015 |
| Laser Line Ceiling and Partitions Limited | Construction | 1998 |
| Laserlec Limited | Administrative & support | 2007 |
| Laserlink Ltd | Information & communication | 2023 |
| Lashifybyjojo Limited | Other services | 2024 |
| Last House on Cemetery Lane Ltd | Information & communication | 2014 |
| Latimont Ltd | Information & communication | 2025 |
| Laudable Limited | Administrative & support | 1971 |
| Launchcube Ltd | Information & communication | 2013 |
| Laura James Enterprises Limited | Hospitality | 2007 |
| Lavish Laundry Ltd | Other services | 2019 |
| Lawtas Mechanical Ltd | Construction | 2025 |
| Layla-Rose Sophie Roddis Limited | Extraterritorial | 2024 |
| Layton Edwards Fallen Stock Limited | Agriculture & fishing | 2019 |
| Lazenby Construction Safety Limited | Construction | 2012 |
| LBT Brick & Facades Limited | Wholesale & retail | 1990 |
| LC Trade Cars Limited | Wholesale & retail | 2009 |
| Lccohen Holdings Limited | Financial services | 2022 |
| LCD Design Limited | Professional & scientific | 2008 |
| LCH Dispatching Limited | Transport & logistics | 2023 |
| LCW Footwear Limited | Wholesale & retail | 2015 |
| LDE Fabrication Services Ltd | Manufacturing | 2020 |
| LDS Surveyors Ltd | Administrative & support | 2017 |
| Le-Raj (Wales) Limited | Hospitality | 2007 |
| Leabeech Limited | Construction | 2024 |
| Lead Indicators Limited | Professional & scientific | 2017 |
| Leadcraft Limited | Construction | 1999 |
| Leading Confidently Ltd | Professional & scientific | 2017 |
| Leading Talent Ltd | Information & communication | 2017 |
| Leadingxtra Ltd | Wholesale & retail | 2022 |
| Leaf Interiors Limited | Wholesale & retail | 2016 |
| Leaping Wing Ltd. | Information & communication | 2015 |
| Learn and Play Early Years Ltd | Health & social care | 2017 |
| Learning Industries Limited | Information & communication | 2001 |
| Leatrend Limited | Extraterritorial | 2025 |
| Leckwith Drive Residents Association Limited | Administrative & support | 2015 |
| Leckwith Properties Limited | Real estate | 2012 |
| LEE Gilbert Optometry Ltd | Professional & scientific | 2017 |
| LEE Walsh Homes Ltd | Real estate | 2025 |
| Legacy 4 Five Limited | Real estate | 2025 |
| Legend of Halloween Jack Ltd | Information & communication | 2017 |
| Legg’S Properties & Lets Ltd | Real estate | 2025 |
| Leigh Smith Operations Ltd | Arts & recreation | 2010 |
| Leigh's Locksmiths (Bridgend) Ltd | Other services | 2026 |
| LEJ Estates Ltd | Real estate | 2025 |
| Lektromek Limited | Construction | 2006 |
| Lemon City Ltd | Other services | 2023 |
| Lensmonkey TV Ltd | Information & communication | 2008 |
| LEO Andrew Lewis Roddis Limited | Extraterritorial | 2024 |
| Leoneast Limited | Extraterritorial | 2026 |
| Leonie Trading Ltd | Wholesale & retail | 2025 |
| Letforce Limited | Professional & scientific | 2013 |
| Letts Solutions Ltd | Professional & scientific | 2013 |
| Levco SA Limited | Hospitality | 2023 |
| Lewis and Watkin Ltd | Other services | 2024 |
| Lewis Brothers Ltd | Administrative & support | 2024 |
| Lewis Construction Services Limited | Construction | 2022 |
| Lewis Holdings Investments Ltd | Real estate | 2021 |
| Lewistown General Stores Limited | Wholesale & retail | 2014 |
| Lewton Properties Limited | Real estate | 2023 |
| Lew’S Mobile Tyres Ltd | Wholesale & retail | 2021 |
| LG Pipe&Mechanical Services Ltd | Manufacturing | 2026 |
| Lgcs Contracts Limited | Construction | 2018 |
| LHW Investments Limited | Real estate | 2022 |
| Libertad Homes Ltd | Real estate | 2023 |
| Liberty 16+ Ltd | Health & social care | 2020 |
| Liberty Community Developments Limited | Construction | 2026 |
| Liberty Independent Living Limited | Health & social care | 2019 |
| Liberty Intervention and Mentoring Services Ltd | Health & social care | 2020 |
| Liberty Placements Ltd | Health & social care | 2015 |
| Liberty Residential Living Limited | Real estate | 2026 |
| Liberty Solutions (Swansea) Limited | Information & communication | 2013 |
| Lifestyle Associates Limited | Other services | 2025 |
| Lifestyle Exxpress Limited | Wholesale & retail | 2025 |
| Lighter Moments Property Ltd | Real estate | 2025 |
| Lights Control Action Ltd | Construction | 2021 |
| Like and Share Limited | Arts & recreation | 2018 |
| Lilly'Y Food Service Ltd | Hospitality | 2024 |
| Limbic Education CYF | Public administration | 2024 |
| Limitless Electrical SW Ltd | Energy | 2024 |
| Limitless MX Ltd | Wholesale & retail | 2025 |
| Lims Holdings Limited | Financial services | 2024 |
| Link Transport Planning Ltd | Professional & scientific | 2023 |
| Linksx Ltd | Professional & scientific | 2024 |
| Lisian Properties Limited | Real estate | 2025 |
| Litchard FC Ltd | Education | 2025 |
| Litchard Tool Hire Ltd | Administrative & support | 2018 |
| Litebulb Media Ltd | Administrative & support | 2016 |
| Little Dragon Studios Ltd | Information & communication | 2025 |
| Little Fishers Swim School Limited | Education | 2014 |
| Little Lewis Group LLP | | 2017 |
| Little Pickle Ltd | Real estate | 2024 |