| Koko Plastering and Rendering Limited | Construction | 2025 |
| Koko Renovations Ltd | Construction | 2025 |
| Kolorkraft Professional Imaging Limited | Professional & scientific | 2007 |
| Konfolktix Ltd | Transport & logistics | 2024 |
| Kooner (UK) Ltd | Wholesale & retail | 2007 |
| Krathezy Ltd | Transport & logistics | 2023 |
| Kristian Exports Limited | Wholesale & retail | 1975 |
| KRM Haulage Limited | Wholesale & retail | 1995 |
| Kroveen Ltd | Transport & logistics | 2024 |
| KRS Recycling Limited | Water & waste | 2014 |
| KSB Greenhouse Ltd | Construction | 2023 |
| KSI HKS Limited | Education | 2019 |
| KSI HKS Property Limited | Real estate | 2019 |
| Ksklep Limited | Wholesale & retail | 2013 |
| KSL Grant Property Solutions Ltd | Real estate | 2021 |
| KSP Secure Limited | Administrative & support | 2026 |
| KTH Property Management Ltd | Real estate | 2018 |
| KTM Barrett Renovations Ltd | Real estate | 2025 |
| Kuldip Singh Limited | Professional & scientific | 2006 |
| KUT Machinery Ltd | Professional & scientific | 2025 |
| Kuvin Home (UK) Limited | Wholesale & retail | 2025 |
| Kuvin Home Woven Edge Limited | Wholesale & retail | 2025 |
| KV Newton Ltd | Administrative & support | 2022 |
| Kylaus Limited | Hospitality | 2006 |
| Kyomenzy Ltd | Administrative & support | 2024 |
| L & R Interiors (Midland) Limited | Construction | 2010 |
| L and D Sawmills Limited | Administrative & support | 2006 |
| L Davis Builders Limited | Construction | 2019 |
| L J Solar Limited | Construction | 2022 |
| L R Developments Ltd | Construction | 2015 |
| L&S Haulage Ltd | Transport & logistics | 2020 |
| L. G. M. Limited | Construction | 1981 |
| L.F.I. (U.K.) Limited | Wholesale & retail | 1988 |
| L.M. & J.S. Stamps Transport Limited | Transport & logistics | 1965 |
| L.M. Private Aesthetics Ltd | Other services | 2023 |
| L.O.R Rigging Ltd | Wholesale & retail | 2025 |
| L.W. Technical Solutions Limited | Professional & scientific | 2025 |
| LA Gorila Ltd | Hospitality | 2020 |
| Lafonia Limited | Information & communication | 2011 |
| LAG Holdings Limited | Hospitality | 2017 |
| LAG Ltd | Other services | 2003 |
| Lagin Drayton Ltd | Hospitality | 2025 |
| LAI LAM Cuisine Limited | Hospitality | 2021 |
| Lamb Residential Limited | Construction | 2025 |
| Lambert Event Management Ltd | Extraterritorial | 2023 |
| Lanbeth Resolutions Limited | Health & social care | 2020 |
| Landham Properties Limited | Real estate | 1993 |
| Landlord Tax Planning and Advice Ltd | Extraterritorial | 2013 |
| Landseer Properties Limited | Real estate | 2013 |
| Lanedig Ltd | Administrative & support | 2024 |
| Language Services Associates (Europe) Limited | Professional & scientific | 2010 |
| Lanizern Ltd | Transport & logistics | 2024 |
| Lanzermiz Ltd | Administrative & support | 2022 |
| Lara Sutherland Consulting Limited | Professional & scientific | 2025 |
| Larkins Environmental Services Limited | Water & waste | 2018 |
| Larkins Transport Limited | Transport & logistics | 2013 |
| Larztious Ltd | Wholesale & retail | 2024 |
| LAT Coaching Ltd | Construction | 2024 |
| Law Incubator CIC | Education | 2022 |
| Lawlevent Limited | Construction | 2022 |
| Laws Jointing Services Ltd | Extraterritorial | 2024 |
| Laxey Events Co Ltd | Hospitality | 2024 |
| LBW Group Ltd | Manufacturing | 2022 |
| LC Business Holdings Limited | Financial services | 2026 |
| LDC Express Courier Ltd | Transport & logistics | 2021 |
| LE1234 Ltd | Professional & scientific | 2024 |
| Lead Associates Limited | Professional & scientific | 2016 |
| Lead the Way WM Ltd | Other services | 2025 |
| Leap Electrical Ltd | Construction | 2022 |
| Leavekous Ltd | Wholesale & retail | 2024 |
| LEE Build & Furnishings Ltd | Manufacturing | 2023 |
| Lees Enterprises Limited | Hospitality | 2013 |
| LEG Trans Ltd | Transport & logistics | 2024 |
| Legacy Doors Ltd. | Construction | 2019 |
| Legesnate Investment Co. Limited | Real estate | 1963 |
| Leguszy Ltd | Transport & logistics | 2023 |
| Leisure Energy Ltd | Construction | 2014 |
| LEM Transported Limited | Other services | 2019 |
| Lentclare Ltd | Transport & logistics | 2024 |
| Leodium Ltd | Administrative & support | 2022 |
| Leonine Limited | Real estate | 2023 |
| Lesaffre UK and Ireland Limited | Wholesale & retail | 1992 |
| Letterfearn Ltd | Transport & logistics | 2022 |
| Leucoser Ltd | Administrative & support | 2021 |
| Levamore Ltd | Wholesale & retail | 2024 |
| Level Check Studios Ltd | Information & communication | 2026 |
| Lewfin Limited | Other services | 2014 |
| Lewis Cleansing Ltd | Administrative & support | 2010 |
| Lewis Commercial Heating Solutions Limited | Construction | 2022 |
| Lewis James Plastering Limited | Construction | 2011 |
| Lexeat Design Consultancy Ltd | Professional & scientific | 2019 |
| LGM Holdings Limited | Financial services | 2005 |
| Lherie Cosmetics Limited | Professional & scientific | 2024 |
| Lhrs Telecom Ltd | Information & communication | 2026 |
| LI Park Ltd | Administrative & support | 2022 |
| Liam Builds IT Ltd | Construction | 2020 |
| Liatharom Ltd | Wholesale & retail | 2022 |
| Lideervant Ltd | Transport & logistics | 2021 |
| Lidemit Ltd | Transport & logistics | 2024 |
| Life Cinematic Ltd | Information & communication | 2011 |