| LSM & Hilary Ltd | Professional & scientific | 2021 |
| LSM Properties Ltd | Real estate | 2020 |
| Lsps Holdings Limited | Financial services | 2026 |
| Lstd Enterprises Limited | Hospitality | 2023 |
| LT MCD Limited | Information & communication | 2024 |
| LT Network Solutions Ltd | Information & communication | 2013 |
| LT Operations Limited | Professional & scientific | 2025 |
| LT Property Services (NE) Ltd | Construction | 2023 |
| Ltll Hubs Limited | Arts & recreation | 2022 |
| LTM Recruitment Specialists Ltd | Administrative & support | 2020 |
| Ltpb Service Management Ltd | Administrative & support | 2026 |
| LTR Wind Limited | Professional & scientific | 2020 |
| Lucagen Consultancy Limited | Professional & scientific | 2019 |
| Luced Consultancy Ltd | Construction | 2023 |
| Luchta Property Services Limited | Construction | 2025 |
| Luciano's North East Ltd | Hospitality | 2019 |
| Lucid Directions Ltd | Information & communication | 2025 |
| Lucinda Kerr Limited | Administrative & support | 2015 |
| Luckies Brewing Ltd | Manufacturing | 2026 |
| Luckies Pubs & Brewing Ltd | Professional & scientific | 2026 |
| Lucky Brew & TAP Ltd | Manufacturing | 2024 |
| Lucky Jiang Limited | Hospitality | 2025 |
| Lucky Mortgages Limited | Financial services | 2024 |
| LUCKY888TAKEAWAY Ltd | Hospitality | 2025 |
| Lucror Limited | Financial services | 2006 |
| Ludex Consulting Limited | Professional & scientific | 2020 |
| Luenyx Limited | Information & communication | 2025 |
| Lugo Hub CIC | Wholesale & retail | 2026 |
| Luigi Bernardelli Limited | Other services | 1963 |
| Luigikhans Hotel Ltd | Hospitality | 2018 |
| Luigikhans Ltd | Hospitality | 2015 |
| Luis Italian Bar & Kitchen Limited | Hospitality | 2022 |
| Luke Coates Engineering Limited | Professional & scientific | 2016 |
| Lukemans Empire Ltd | Real estate | 2024 |
| Lulu & SAS Bridal Co. Ltd | Wholesale & retail | 2024 |
| LUM Reek Ltd | Real estate | 2023 |
| LUM Reek Ventures Ltd | Professional & scientific | 2024 |
| Lumacore Fire & Security Ltd | Construction | 2025 |
| Lumacore Group Ltd | Financial services | 2026 |
| Lumacore Ltd | Construction | 2026 |
| Lumanorth Ltd | Information & communication | 2022 |
| Lumen Shalya Ltd | Professional & scientific | 2026 |
| Lumi-Novo Holdings Limited | Professional & scientific | 2023 |
| Lumi-Novo Limited | Professional & scientific | 2024 |
| Lumina NE Ltd | Construction | 2025 |
| Lumina Property Group NE Ltd | Real estate | 2025 |
| Luminex Property Group Ltd | Real estate | 2025 |
| Luminous Group Limited | Information & communication | 2004 |
| Lumley Opticals Limited | Manufacturing | 2011 |
| Lumoscape Ltd | Arts & recreation | 2016 |
| Lumovita Limited | Arts & recreation | 2025 |
| Lunar Lynx Limited | Information & communication | 2024 |
| Lunar Skills Limited | Construction | 2023 |
| Lunaris Medical Ltd | Manufacturing | 2025 |
| Luni Stone Ltd | Wholesale & retail | 2024 |
| Luqama Ltd | Wholesale & retail | 2022 |
| Luqman Homes Ltd | Real estate | 2026 |
| Lust for Life Campervan Hire Limited | Administrative & support | 2017 |
| Lust Interiors Ltd | Wholesale & retail | 2023 |
| Lutaferni Ltd | Real estate | 2024 |
| Luton Cleaners Ltd | Administrative & support | 2016 |
| Luvclo Ltd | Wholesale & retail | 2025 |
| LUX C Ltd | Wholesale & retail | 2022 |
| Luxe Bathrooms NE Ltd | Construction | 2026 |
| Luxe Emporium X Limited | Wholesale & retail | 2021 |
| Luxe England Limited | Wholesale & retail | 2015 |
| Luxe Floors Ltd | Wholesale & retail | 2019 |
| Luxe Property Development Ltd | Construction | 2023 |
| Luxe Tea Royale Ltd | Wholesale & retail | 2026 |
| Luxe Wheeltrailers Ltd | Wholesale & retail | 2025 |
| Luxefurn Ltd | Wholesale & retail | 2025 |
| Luxley House Management Limited | Real estate | 2024 |
| Luxmi Online Limited | Wholesale & retail | 2022 |
| Luxsnacks Limited | Wholesale & retail | 2026 |
| Luxurious Findings Ltd | Wholesale & retail | 2024 |
| Luxury Auto Wrap & Tint Ltd | Wholesale & retail | 2023 |
| Luxury Coach Travel Ltd | Transport & logistics | 2009 |
| Luxury Sent Ltd | Wholesale & retail | 2020 |
| LV Cafe Ltd | Hospitality | 2025 |
| LV Orthopaedics Ltd | Health & social care | 2021 |
| Lviv International Food Limited | Wholesale & retail | 2023 |
| Lvro Retail Ltd | Wholesale & retail | 2024 |
| LVS Newcastle Ltd | Information & communication | 2026 |
| LW Bids Limited | Professional & scientific | 2018 |
| LW Medical Products Ltd | Wholesale & retail | 2020 |
| LW Serviced Apartments Limited | Other services | 2022 |
| LWS Construction Services Ltd | Construction | 2019 |
| LY Training & Consultancy Ltd | Education | 2022 |
| Lycansoft Ltd | Information & communication | 2018 |
| Lyceum Capital Property Partners Limited | Real estate | 2018 |
| Lydford Court Property Management Limited | Real estate | 2020 |
| Lyles of Newcastle Limited | Wholesale & retail | 1977 |
| Lyma Group Ltd | Health & social care | 2024 |
| Lynas Place Public Open Space Management Limited | Real estate | 2008 |
| Lynch Media Limited | Professional & scientific | 2005 |
| Lynda and John's Property Services Ltd | Real estate | 2021 |
| Lyndale Robert Limited | Real estate | 2001 |
| Lyndale-Wilson Properties Limited | Real estate | 2001 |
| Lyndholme Management Company Limited | Real estate | 2013 |
| Lyndon Consulting Limited | Professional & scientific | 2026 |