| Key Accountants (Derby) Ltd | Professional & scientific | 2021 |
| Key Accountants (Hinckley) Ltd | Professional & scientific | 2026 |
| Key Accountants Midlands Ltd | Professional & scientific | 2008 |
| Key Marketing Ltd | Manufacturing | 2020 |
| Keynes Care Ltd | Administrative & support | 2024 |
| Keytech Systems Limited | Wholesale & retail | 2000 |
| Killer Couture Ltd | Wholesale & retail | 2017 |
| KIN Psychology Ltd | Education | 2026 |
| Kingsley Logistics Ltd | Transport & logistics | 2020 |
| Kingsoak Homes Limited | Construction | 1986 |
| Kinsure Ltd | Professional & scientific | 2026 |
| Kisp Enterprise CIC | Education | 2022 |
| Kisp Limited | Education | 2020 |
| Kites Well Limited | Real estate | 2019 |
| KKK Security Ltd | Administrative & support | 2020 |
| Kleiberit Adhesives UK Ltd | Manufacturing | 2018 |
| Klimate Labs Ltd | Water & waste | 2018 |
| KLM Plant Services Limited | Construction | 2016 |
| KLP (Derbyshire) Ltd | Manufacturing | 2016 |
| Knotcraft Ltd | Wholesale & retail | 2023 |
| Knotty’S Imaginarium Ltd | Wholesale & retail | 2025 |
| KNR Global Ltd | Wholesale & retail | 2024 |
| Kompressor Heat Ltd | Construction | 2022 |
| Kovacs Limited | Manufacturing | 2000 |
| Kovacs Properties Limited | Real estate | 2015 |
| KP Repairs & Maintenance Ltd | Administrative & support | 2024 |
| Krafty FOX Ltd | Wholesale & retail | 2022 |
| Krow Consultancy Ltd | Professional & scientific | 2023 |
| KSA Consulting Engineers Limited | Professional & scientific | 2002 |
| Ktmac Ltd | Real estate | 2024 |
| Kubus COV Ltd | Wholesale & retail | 2025 |
| Kubus Grocery Ltd | Wholesale & retail | 2023 |
| Kudos Designs and Websites Ltd | Professional & scientific | 2023 |
| Kumerica Ltd | Information & communication | 2020 |
| KWT Development Ltd | Real estate | 2016 |
| KZR Autos Ltd | Wholesale & retail | 2025 |
| L & Jayes Properties Ltd | Real estate | 2025 |
| L & K Foundry Gym Ltd | Arts & recreation | 2025 |
| L M Repairs Ltd | Transport & logistics | 2014 |
| L&D Courier Services Ltd | Transport & logistics | 2024 |
| L.M.H. Engineering Midlands Ltd | Professional & scientific | 2011 |
| LA Coiffure Ltd | Other services | 2005 |
| LAB Fifteen Co Ltd | Wholesale & retail | 2021 |
| Lafarge Building Materials Limited | Professional & scientific | 1997 |
| Lafarge International Holdings Limited | Financial services | 1952 |
| Lafarge Redland Readymix Limited | Financial services | 1944 |
| LAH Plant Services Ltd | Manufacturing | 2024 |
| Laight Property Improvements Ltd | Construction | 2021 |
| Lambert QMS Services Limited | Professional & scientific | 2023 |
| Land of Mercia Ltd | Information & communication | 2023 |
| Land Recovery (Dewsbury) Ltd | Extraterritorial | 2022 |
| Land Recovery Limited | Mining & quarrying | 1982 |
| Land Recovery Rail Limited | Construction | 2011 |
| Landbridge Logistics GB Ltd | Transport & logistics | 2021 |
| Lander Lettings Ltd | Real estate | 2013 |
| Lander Ventures Limited | Real estate | 2012 |
| Lanza Group Ltd | Real estate | 2017 |
| Lanza Homes Ltd | Construction | 2016 |
| Lanzamar Developments Limited | Professional & scientific | 2017 |
| Latch HR Ltd | Administrative & support | 2024 |
| Lathan Rowell Land and Property Consultants Ltd | Administrative & support | 2016 |
| Laurentiu Trans Ltd | Transport & logistics | 2016 |
| Lawnmower Bags Limited | Manufacturing | 2017 |
| Lawnwood Properties Ltd | Real estate | 2014 |
| Lawrence & Finley Architects Limited | Professional & scientific | 2019 |
| Lawrence Trailers Ltd | Administrative & support | 2026 |
| Laxmi MAA Ltd | Wholesale & retail | 2014 |
| Laxmii Ltd | Real estate | 2025 |
| Lazybooks Ltd | Information & communication | 2026 |
| Lazydog Distillery Ltd | Manufacturing | 2019 |
| LB Planning Consultancy Ltd | Professional & scientific | 2026 |
| LBW Properties Limited | Real estate | 2021 |
| Lccda Management Co-Operative Limited | Professional & scientific | 1984 |
| LDK Property Investments Ltd | Real estate | 2025 |
| LDP Accounts Limited | Professional & scientific | 2019 |
| LDR Electrical Solutions Ltd | Construction | 2026 |
| LDW Electrical Services Ltd | Construction | 2025 |
| LE Vana Care Limited | Health & social care | 2023 |
| Leader Business Solutions Limited | Professional & scientific | 2013 |
| Leader CNC Consultancy Ltd | Professional & scientific | 2004 |
| Leader CNC Technologies Limited | Administrative & support | 1998 |
| LEE Cooper Independent Funeral Director Limited | Other services | 2008 |
| LEE Griffiths EA Limited | Real estate | 2025 |
| LEE Wells Auto Bodies Ltd | Manufacturing | 2005 |
| Leecol Communications Ltd | Administrative & support | 2015 |
| Lehane Earthmoving Limited | Construction | 2012 |
| Leicester Heavy Haulage Ltd | Transport & logistics | 2026 |
| Leicester Road Ravenstone Management (NO 1) Limited | Households | 1994 |
| Leicestershire Building Contractors Ltd | Construction | 2020 |
| Leigh White Photography Ltd | Professional & scientific | 2022 |
| Leighton Catering Ltd | Hospitality | 2018 |
| Let's Have a Bath Productions Ltd | Information & communication | 2025 |
| Let's Live Here Ltd | Real estate | 2018 |
| Levelup - Sustainability Recruiting Ltd | Administrative & support | 2025 |
| Lexii Ltd | Wholesale & retail | 2020 |
| LG Elevators Ltd | Construction | 2014 |
| Liam Carey Limited | Information & communication | 2026 |
| Libralink Ltd | Hospitality | 2024 |
| Lidwell Properties Ltd | Households | 2022 |
| Life Force Water Ltd | Manufacturing | 2009 |