| Kpcco Ltd | Wholesale & retail | 2024 |
| Krafty Shed Ltd | Arts & recreation | 2020 |
| Kramp U.K. Ltd. | Wholesale & retail | 1973 |
| KRB Installations (Holdings) Limited | Financial services | 2024 |
| KRB Installations Limited | Construction | 2002 |
| Kristal Cleaning Company Ltd | Administrative & support | 2023 |
| Kristy’S Studio Ltd | Other services | 2024 |
| KT Collection Foods Limited | Hospitality | 2025 |
| KT Ivory Haulage and Storage Trading Limited | Administrative & support | 2012 |
| KTC Properties Ltd. | Hospitality | 2020 |
| L E Magasin Limited | Information & communication | 2003 |
| L Jones Management Limited | Real estate | 2019 |
| L&T Consult Limited | Professional & scientific | 2024 |
| L.E.F Landscaping Ltd | Administrative & support | 2023 |
| L.M Gift and Boutique Ltd | Wholesale & retail | 2026 |
| L.M Gift Boutique Ltd | Wholesale & retail | 2024 |
| L.M Gifts Boutiques Ltd | Wholesale & retail | 2025 |
| LA Peripherals Ltd | Information & communication | 2011 |
| LA Tania Associates Limited | Professional & scientific | 2026 |
| Labres Limited | Information & communication | 2018 |
| Ladcroft Limited | Professional & scientific | 1990 |
| Lains Coffee House Ltd | Hospitality | 2025 |
| LAK Door Services Ltd | Construction | 2023 |
| Langford Assets Ltd. | Real estate | 1998 |
| Langford Bread and Honey Limited | Agriculture & fishing | 2020 |
| Langford Fish and Chips Limited | Hospitality | 2025 |
| Langford Windows Doors and Conservatories Limited | Construction | 2004 |
| Larwood Gent Ltd | Administrative & support | 1998 |
| Laser Grafix Sales Limited | Administrative & support | 1998 |
| Laser Productions Limited | Manufacturing | 2019 |
| Laserprep Ltd | Administrative & support | 2025 |
| Lashes by AMY Ltd | Other services | 2019 |
| Last House Limited | Real estate | 2021 |
| Laura Tait Ltd | Arts & recreation | 2017 |
| Lawdata Limited | Professional & scientific | 1983 |
| Lawns Court Residents Association Limited | Households | 1986 |
| LBP Optics Limited | Manufacturing | 2017 |
| Lcit Limited | Information & communication | 2020 |
| LDB Contractors Ltd | Construction | 2026 |
| LDN Comedy Ltd | Information & communication | 2023 |
| LDN Residences Ltd | Real estate | 2021 |
| Leap World Ltd | Professional & scientific | 2019 |
| Ledgers Accountancy Solutions Limited | Professional & scientific | 2009 |
| Lees Carpentry & Construction Limited | Construction | 2024 |
| Leoline Productions Ltd | Arts & recreation | 2022 |
| Leonard Services Ltd | Professional & scientific | 2022 |
| Leonie Pujol Limited | Administrative & support | 2017 |
| Leosat Solutions Ltd | Professional & scientific | 2021 |
| Letec U.K. Ltd | Financial services | 2025 |
| Lets ACT Excel Performance Preparation Limited | Education | 2023 |
| Level Education Ltd | Education | 2025 |
| Leverkirk Limited | Professional & scientific | 1991 |
| LFM Bookkeeping Services Ltd | Professional & scientific | 2022 |
| LG E-Commerce Ltd | Wholesale & retail | 2021 |
| LH Elite PA Services Ltd | Administrative & support | 2022 |
| LH Management Consultancy Limited | Professional & scientific | 2022 |
| Libris Accounting Ltd | Professional & scientific | 2010 |
| Liebherr - Great Britain Limited | Manufacturing | 1960 |
| Liebherr-Rental Limited | Administrative & support | 2007 |
| Liebig Polaris Ltd | Education | 2023 |
| Life Academies Trust | Education | 2012 |
| Life Tamed Ltd | Professional & scientific | 2020 |
| Lightening Distribution and Movers Ltd | Transport & logistics | 2015 |
| Lighthouse Marketing Solutions Ltd | Hospitality | 2025 |
| Limbalance Ltd | Wholesale & retail | 2020 |
| Linked Partnership Ltd | Professional & scientific | 2023 |
| Linkfolder Limited | Real estate | 2005 |
| Lipiap Care Limited | Health & social care | 2015 |
| Lisa Horton Crafts Ltd | Wholesale & retail | 2011 |
| Little Animal Ltd | Arts & recreation | 2022 |
| Little Buttons Limited | Administrative & support | 2008 |
| Little Fires Ltd | Professional & scientific | 2019 |
| Little Recreations Ltd | Extraterritorial | 2021 |
| LLB Ltd | Information & communication | 2025 |
| Lmbse Ltd | Information & communication | 2024 |
| LME Productions Limited | Information & communication | 2015 |
| LME UK Trading Ltd | Professional & scientific | 2023 |
| Lock & Glaze Herts/Beds Limited | Administrative & support | 2026 |
| Locksmith Services (Bedfordshire) Limited | Wholesale & retail | 2025 |
| Lockstate Limited | Manufacturing | 2021 |
| Logistics Content Ltd | Manufacturing | 2023 |
| LOK Creative Ltd | Information & communication | 2022 |
| Lola-Rose Ltd | Arts & recreation | 2023 |
| Loline Interiors Ltd | Wholesale & retail | 2014 |
| London Voiceover Ltd | Information & communication | 2026 |
| Lost Souls Creative Limited | Professional & scientific | 2016 |
| LOU Lou’S Hair & Beauty Lounge Limited | Other services | 2025 |
| Lou-Lou's Hair and Beauty Limited | Other services | 2019 |
| Love Biggleswade Limited | Hospitality | 2010 |
| Lovell Building & Carpentry Limited | Construction | 2012 |
| LOW Cost Therapy Community Interest Company | Health & social care | 2026 |
| LPE Consultancy Limited | Information & communication | 2022 |
| LPE Property Limited | Financial services | 2023 |
| LS People Consulting Limited | Administrative & support | 2025 |
| LS Surveillance Ltd | Wholesale & retail | 2026 |
| Lthl WPN Ltd | Information & communication | 2018 |
| Ludo Energy Consulting Ltd | Professional & scientific | 2026 |
| Luebensoft Ltd | Information & communication | 2024 |
| Luparlécrit Ltd. | Professional & scientific | 2023 |
| Lusso Logistics Ltd | Transport & logistics | 2022 |