| London Sound & Lighting Ltd | Manufacturing | 2024 |
| Long Bear Limited | Wholesale & retail | 2014 |
| Longbridge Investors Limited | Real estate | 2015 |
| Longcroft Care Home Limited | Health & social care | 2008 |
| Longcross Surveys Limited | Professional & scientific | 2007 |
| Longfield Capital Ltd | Professional & scientific | 2008 |
| Longfield Plumbing & Heating Supplies Limited | Wholesale & retail | 1999 |
| Longmeade Consultancy Ltd | Professional & scientific | 2010 |
| Longmeade FT | Administrative & support | 2022 |
| Longmeade One Ltd | Real estate | 2024 |
| Longmeade Sports Ltd | Arts & recreation | 2019 |
| Longmeade Ventures Ltd | Real estate | 2020 |
| Longmeadow Limited | Real estate | 2010 |
| Lorek Limited | Information & communication | 2013 |
| Lorek Property Ltd | Real estate | 2026 |
| Lotipic Limited | Information & communication | 2021 |
| Lotma Limited | Wholesale & retail | 2025 |
| Lotties Gold Rush Ltd | Manufacturing | 2025 |
| Lotus Care Ltd | Health & social care | 2015 |
| Lotus Caring Ltd | Health & social care | 2019 |
| Loudworks Ltd | Manufacturing | 2023 |
| Loughton Real Estate Ltd | Real estate | 2021 |
| Louisa's Dog Grooming Salon Ltd | Other services | 2022 |
| Loulabell UK Ltd | Other services | 2020 |
| Love EAT Sleep Soccer Limited | Arts & recreation | 2017 |
| Loveday Properties Limited | Real estate | 1997 |
| Loveland Limited | Health & social care | 2019 |
| Lovely Transport Ltd | Transport & logistics | 2024 |
| Lovett Building Contractors Ltd | Construction | 2015 |
| LOW Carbon Technologies Construction Limited | Construction | 2008 |
| LP Fire & Security Systems Limited | Administrative & support | 2012 |
| LP Real Estate Limited | Real estate | 2024 |
| LPM Group Ltd | Construction | 2021 |
| LPS Communications Ltd | Construction | 2023 |
| LPS Plumbing Services Ltd | Construction | 2022 |
| LQ Property London Limited | Real estate | 2019 |
| Lrose Property Improvements Ltd | Construction | 2026 |
| LRP Ltd | Wholesale & retail | 2021 |
| LRT Communications Ltd | Information & communication | 2025 |
| LRU Waterproofing Solutions Ltd | Construction | 2016 |
| LS Acorn Ltd | Manufacturing | 2011 |
| LS Graphic Installations Ltd | Other services | 2021 |
| LS Machinery & Tools Ltd | Wholesale & retail | 2018 |
| LS Plant Hire Ltd | Administrative & support | 2021 |
| LS Project Support Services Limited | Administrative & support | 2019 |
| LSB Taxis Ltd | Transport & logistics | 2023 |
| LSC Property Ltd | Real estate | 2023 |
| Lseducationservices Limited | Education | 2023 |
| LSM Car Sales Limited | Wholesale & retail | 2019 |
| LTB Limited | Construction | 2022 |
| LTR Property Investors Limited | Real estate | 2021 |
| LUC Engineer ING Ltd | Extraterritorial | 2024 |
| Luca Expedition Limited | Wholesale & retail | 2024 |
| Luca-S Transportation Ltd | Transport & logistics | 2018 |
| Lucas Paul Services Ltd | Construction | 2014 |
| Lucian Trans Ltd | Transport & logistics | 2017 |
| Lucidus Construction Ltd | Construction | 2025 |
| Lucky Jade Trading Ltd | Hospitality | 2024 |
| Lucky Legend Competitions Limited | Arts & recreation | 2026 |
| Lucy KM Limited | Health & social care | 2015 |
| LUCY2014 Transport Limited | Transport & logistics | 2014 |
| Luggage 4 U Limited | Wholesale & retail | 2017 |
| Luke Scott Stoves Ltd | Construction | 2024 |
| Lukes Tyres Limited | Wholesale & retail | 2016 |
| Lully Paws Limited | Extraterritorial | 2022 |
| Lulu’S Bunns Ltd | Manufacturing | 2025 |
| Lumen Estates Ltd | Real estate | 2025 |
| Lummy JAY Concepts Ltd | Health & social care | 2013 |
| Lupetta Ltd | Health & social care | 2026 |
| Lusail Ltd | Real estate | 2022 |
| Lush Gear Ltd | Wholesale & retail | 2025 |
| Lutati Ltd | Administrative & support | 2025 |
| LUX SE Design & Build Ltd | Extraterritorial | 2024 |
| LUX Tanning Ltd | Other services | 2025 |
| Luxcaramelwigs Limited | Other services | 2020 |
| Luxe Developers Ltd | Construction | 2020 |
| Luxe Hair Hub Ltd | Other services | 2025 |
| Luxmove Limited | Other services | 2018 |
| Luxolina Property Ltd | Real estate | 2024 |
| Luxury Lifestyle Ltd | Other services | 2017 |
| LUZ Electrical Ltd | Construction | 2023 |
| LV Associates Limited | Administrative & support | 2026 |
| LVC Electrical Limited | Construction | 2019 |
| LW Auto Repairs Limited | Wholesale & retail | 2024 |
| Lydstar Properties Ltd | Real estate | 2025 |
| Lynx Electrical Services Limited | Construction | 1997 |
| Lynx Engineering (Kent) Limited | Construction | 1997 |
| Lyon Court (Rochester) Management Company Limited | Households | 2007 |
| Lyons Bathrooms Limited | Construction | 2020 |
| Lyons Build Limited | Construction | 2015 |
| Lyopharm Consulting Ltd | Professional & scientific | 2022 |
| Lyric Mews (SE26) Management Company Limited | Professional & scientific | 1996 |
| LZM Consulting Ltd | Professional & scientific | 2026 |
| M & C Villas in Italy Ltd | Administrative & support | 2008 |
| M & N Express Transport Ltd | Transport & logistics | 2025 |
| M & O Capital Ltd | Construction | 2021 |
| M 2 Technical Services (North Wales) Ltd | Construction | 2008 |
| M a Green & Daughters Ltd | Real estate | 2024 |
| M a H Steel Limited | Other services | 2010 |
| M a Myries Property Investment Ltd | Real estate | 2024 |