| Lucy Victoria Designs Group Ltd | Professional & scientific | 2021 |
| Luiso Investments Ltd | Financial services | 2024 |
| Lukai Fitness Ltd | Arts & recreation | 2026 |
| Luke Court (Brentwood) Management Company Limited | Households | 2017 |
| Luke DU Casse Limited | Arts & recreation | 2013 |
| Luki Properties Ltd | Real estate | 2026 |
| Lumane Ltd | Professional & scientific | 2011 |
| Lumantics Ltd | Professional & scientific | 2018 |
| Lumen Energy & Environment Limited | Professional & scientific | 2019 |
| Lumeo Films Ltd | Professional & scientific | 2025 |
| Lumiere Acquisitions Limited | Construction | 2015 |
| Lumiere Designs Limited | Construction | 2015 |
| Lumiloo Limited | Manufacturing | 2024 |
| Lumin Contract Limited | Construction | 2020 |
| Lumin GRP Limited | Financial services | 2020 |
| Lumin Haus Limited | Construction | 2019 |
| Luminar Developments Limited | Construction | 2013 |
| Luminar Homes Limited | Real estate | 2020 |
| Luminate-Events Limited | Professional & scientific | 2010 |
| Lumino Tech Ltd | Information & communication | 2025 |
| Luna Hair Salon Ltd | Other services | 2023 |
| Luna Remote Systems Ltd | Administrative & support | 2014 |
| Luna Remotes (UK) Ltd | Information & communication | 2023 |
| Luna Rising Records Ltd | Information & communication | 2024 |
| Lunar Accountancy Ltd | Professional & scientific | 2013 |
| Lunar Real Estate Limited | Real estate | 2025 |
| Lunch House Ltd | Hospitality | 2025 |
| Lunchserve Limited | Hospitality | 2010 |
| Lundbeck Group Limited | Professional & scientific | 1994 |
| Lundbeck Limited | Wholesale & retail | 1972 |
| Lundbeck Pharmaceuticals Limited | Professional & scientific | 1994 |
| Lundbeck UK LLP | | 2009 |
| Lundon Scaffolding Ltd | Construction | 2024 |
| Lunu Miris Ltd | Hospitality | 2026 |
| Lunwell Group Limited | Real estate | 2025 |
| LUO Property Ltd | Real estate | 2025 |
| Lustrans Ltd | Professional & scientific | 2017 |
| Luto and SON Construction Ltd | Construction | 2021 |
| Luvista Ltd | Households | 2025 |
| LUX END Ltd | Real estate | 2024 |
| LUX Nails Land Ltd | Other services | 2025 |
| LUX Property Assets LLP | | 2013 |
| LUX Security Doors Ltd | Construction | 2022 |
| LUX Spacey Ltd | Construction | 2026 |
| LUX Wxches Ltd | Wholesale & retail | 2023 |
| Luxan T&L Ltd | Transport & logistics | 2025 |
| Luxe AV & Events Ltd | Other services | 2022 |
| Luxe Dessert Group Limited | Wholesale & retail | 2026 |
| Luxe Music Ltd | Administrative & support | 2017 |
| Luxunq Ltd | Wholesale & retail | 2024 |
| Luxury Carpets & Furniture Ltd | Wholesale & retail | 2018 |
| Luxury City and Spa Guide Limited | Administrative & support | 2019 |
| Luxury Escape Holidays Limited | Administrative & support | 2019 |
| Luxury Goods Trading Limited | Wholesale & retail | 2024 |
| Luxury Living Apartments Ltd | Households | 2023 |
| Luxury Tinting Ltd | Wholesale & retail | 2020 |
| Luxxuro Courier Services Ltd | Transport & logistics | 2019 |
| Lvello Ltd | Administrative & support | 2025 |
| Lviz Ltd | Real estate | 2018 |
| LVK Global Ltd | Professional & scientific | 2017 |
| LVS Legal Ltd | Professional & scientific | 2022 |
| LW Event Hire Limited | Administrative & support | 2021 |
| LW88 Ltd | Information & communication | 2014 |
| Lwnet Limited | Education | 2025 |
| LX Productions Ltd | Administrative & support | 2022 |
| LX Real Estate Limited | Real estate | 2024 |
| LXE Ltd | Other services | 2024 |
| Lydbrook Trading Limited | Construction | 2013 |
| Lydia Mccarthy-Keen Ltd | Manufacturing | 2019 |
| LYN Kuan Limited | Professional & scientific | 2023 |
| Lynbo Property Management Ltd | Real estate | 2023 |
| Lynch H&S Limited | Construction | 2021 |
| Lynchstone Glazing Group Ltd | Manufacturing | 2021 |
| Lyndhurst Change Consultants Ltd | Professional & scientific | 2016 |
| Lyndon Peter Jeffery Ltd | Administrative & support | 2015 |
| Lynds Consulting Services Ltd | Professional & scientific | 2017 |
| Lynne & Anne Co Ltd | Health & social care | 2015 |
| Lynson Consultancy Services Ltd | Professional & scientific | 2018 |
| Lynton Foster | Professional & scientific | 2001 |
| Lynwood Solicitors Limited | Professional & scientific | 2015 |
| M & a Energy Consulting Ltd | Professional & scientific | 2013 |
| M & J Trans Ltd | Construction | 2013 |
| M & M Products Limited | Wholesale & retail | 1990 |
| M & N Traders Limited | Wholesale & retail | 1995 |
| M & S Valeting Ltd | Wholesale & retail | 2023 |
| M & T 365 Consulting Limited | Financial services | 2025 |
| M a Optics Ltd | Health & social care | 2014 |
| M B Power&Lighting Limited | Construction | 2013 |
| M Bahadur Hygienist Ltd | Health & social care | 2023 |
| M Butt Medical Limited | Health & social care | 2022 |
| M C Minett Limited | Professional & scientific | 2010 |
| M Carepath Ltd | Health & social care | 2024 |
| M Clack Contractor Services Ltd | Construction | 2006 |
| M Construction (London) Limited | Other services | 2019 |
| M D M Property Consultants Limited | Professional & scientific | 2022 |
| M D Properties Limited | Real estate | 2001 |
| M E C Grab Services Limited | Water & waste | 2001 |
| M Expert Construction Ltd | Construction | 2018 |
| M J Hughes Design Limited | Professional & scientific | 2004 |
| M J Lynch Limited | Construction | 2014 |