| LEE Hutchinson Instrument Engineering Ltd | Manufacturing | 2013 |
| LEE Jackson Projects Ltd | Professional & scientific | 2023 |
| Leedsug Ltd | Construction | 2026 |
| Leeks DIY & Hardware Limited | Wholesale & retail | 2011 |
| Leife Limited | Administrative & support | 2025 |
| Leighton Property Services Ltd | Real estate | 2025 |
| Leinster Property Investments Limited | Real estate | 2016 |
| Leinster Property Management Limited | Real estate | 2019 |
| Leinster Property Services Limited | Construction | 2011 |
| Leisure Motor-Sport Services Limited | Arts & recreation | 1992 |
| Lek's Thai Cafe Ltd | Hospitality | 2025 |
| Lekker Developments Limited | Construction | 2025 |
| Lemon Business Solutions Ltd | Administrative & support | 2006 |
| Lenergy Consulting Limited | Professional & scientific | 2018 |
| Lenton Group Limited | Financial services | 2019 |
| Lenton Marketing Limited | Information & communication | 2011 |
| Lenton Property Ltd | Real estate | 2018 |
| Leoh Communications Ltd | Construction | 2024 |
| Lesley Palmer Advertising Co Ltd | Professional & scientific | 2019 |
| Lets Go Cycling CIC | Education | 2025 |
| Letwin Thompson Ltd | Health & social care | 2020 |
| Levan Kitchen Ltd | Hospitality | 2023 |
| Leven Energy Solutions Ltd | Professional & scientific | 2026 |
| Leven Road Stores Ltd | Wholesale & retail | 2008 |
| Leven Vale DP Ltd | Health & social care | 2011 |
| Levenside Limited | Professional & scientific | 2018 |
| Lewis Lawlor Limited | Construction | 2018 |
| LF Removals and Services Ltd | Manufacturing | 2025 |
| LFM Offshore Ltd | Manufacturing | 2022 |
| LFN Investments Limited | Real estate | 2022 |
| Lgmm Ltd | Real estate | 2024 |
| LGT Access Ltd | Manufacturing | 2023 |
| Lgtt Limited | Wholesale & retail | 2025 |
| LHL Inspection Services Ltd | Construction | 2024 |
| LHS Electrics Limited | Manufacturing | 2021 |
| LIA Aerospace Ltd | Transport & logistics | 2021 |
| Liam Cosh Interiors Ltd | Professional & scientific | 2015 |
| Libbys Locks HGF Ltd | Other services | 2024 |
| Lifestyle Healthcare Ltd. | Manufacturing | 1987 |
| Lift Right Weightlifting CIC | Arts & recreation | 2026 |
| Lifting Specialist Ltd | Professional & scientific | 2022 |
| Light Comms Ltd | Construction | 2021 |
| Light Matters Ltd | Other services | 2025 |
| Lighthouse Navigation NE Community Interest Company | Education | 2021 |
| Lighthouse Nursery Limited | Education | 2009 |
| Like US (NE) Limited | Administrative & support | 2023 |
| Lillian Joyce Limited | Real estate | 2024 |
| Lily Luxe Studio Ltd | Other services | 2025 |
| Lime Assets (NE) Limited | Real estate | 2024 |
| Lime Green Services Ltd | Construction | 2026 |
| Limitless Allstars CIC | Wholesale & retail | 2018 |
| Limitless Sport and Services Ltd | Arts & recreation | 2018 |
| Lincoln Group Ltd | Hospitality | 2019 |
| Lincoln Lifting International Ltd | Construction | 2023 |
| Linden Growth Solutions Limited | Professional & scientific | 2019 |
| Linden Project Services Ltd | Professional & scientific | 2012 |
| Lingill Limited | Professional & scientific | 2018 |
| Links Integrated Systems Ltd | Construction | 2024 |
| Linthorpe BED Centre Limited | Wholesale & retail | 2002 |
| Linthorpe Internals Ltd | Construction | 2021 |
| Litc Limited | Construction | 2017 |
| Little Big Top Leisure Limited | Arts & recreation | 2025 |
| Little Miss MOP Ltd | Administrative & support | 2021 |
| Little Paws Day Care & Boarding Limited | Households | 2021 |
| Little Starfish Limited | Real estate | 2021 |
| Livingstion Limited | Wholesale & retail | 2025 |
| Livingstone M Construction Company Ltd | Construction | 2021 |
| Livinlittle Ltd | Wholesale & retail | 2022 |
| Lizlar Kreations Limited | Manufacturing | 2025 |
| LJ Instrument Services Limited | Professional & scientific | 2018 |
| LJE Couriers Ltd | Transport & logistics | 2026 |
| LJH Site Services Ltd | Professional & scientific | 2025 |
| LJJ Trustee Limited | Other services | 2021 |
| LJL Technical Services Ltd | Professional & scientific | 2016 |
| LJM Inspection Solutions Ltd | Professional & scientific | 2025 |
| LJS Electrical Engineering Ltd | Construction | 2019 |
| LJS Real Estate Ltd | Real estate | 2020 |
| LK Sade Ltd | Professional & scientific | 2018 |
| Lklr Renewable Energy Ltd | Energy | 2020 |
| LLE Enviro Ltd | Professional & scientific | 2021 |
| LLH Cabin Sales Ltd | Wholesale & retail | 2024 |
| LLO Inspection Services Limited | Construction | 2019 |
| Lloyd Electrical Engineering Ltd | Manufacturing | 2011 |
| Lloyds Jewellery Ltd | Wholesale & retail | 2011 |
| Lmfs Management Ltd | Administrative & support | 2025 |
| LMJ Estates Group Ltd | Real estate | 2025 |
| LMM Property Solutions Ltd | Hospitality | 2023 |
| LMP Refinish Ltd | Other services | 2018 |
| LNK Property Rentals Ltd | Real estate | 2024 |
| Local Minibus Hire Ltd | Transport & logistics | 2015 |
| Local Specific Limited | Information & communication | 2010 |
| Lock Gates Hartlepool Limited | Hospitality | 2019 |
| Locksemerstock Ltd | Administrative & support | 2025 |
| Locumdrive Ltd | Construction | 2023 |
| Lodestar Consultancy Services Ltd | Professional & scientific | 2018 |
| Loftatech Limited | Professional & scientific | 2016 |
| LOG Cabin Fruits Ltd | Wholesale & retail | 2015 |
| Log-Star Limited | Administrative & support | 2002 |
| Logic Manufactured Bespoke Limited | Manufacturing | 2011 |
| Logic Street & Park Furniture Limited | Extraterritorial | 2021 |