| Lonlaw Limited | Professional & scientific | 1997 |
| Look at ME LAM Ltd | Wholesale & retail | 2025 |
| LOP Electrical Ltd | Manufacturing | 2022 |
| Lopez and White Partnership Limited | Professional & scientific | 2017 |
| Lorder Ltd | Hospitality | 2023 |
| Lorena Cleaning Company Ltd | Administrative & support | 2025 |
| Lost and Found Architects Practice Ltd | Professional & scientific | 2022 |
| Lost and Found Interiors Ltd | Professional & scientific | 2023 |
| Lotmod Limited | Wholesale & retail | 1989 |
| Lotus Lily Ltd | Real estate | 2018 |
| Louise Brown Coaching Ltd | Professional & scientific | 2020 |
| Love Soil | Education | 2026 |
| Love Windows & Doors Ltd | Construction | 2021 |
| Love Your Home BS Ltd | Construction | 2018 |
| Lowalk Limited | Administrative & support | 2017 |
| Lowell Investments Limited | Administrative & support | 2005 |
| Lowell Nominees Limited | Administrative & support | 2017 |
| Lower Derwent Fisheries Ltd | Administrative & support | 2016 |
| Loyalé Laces Limited | Other services | 2024 |
| Loze Consultancy Ltd | Professional & scientific | 2024 |
| LR Strategy Limited | Professional & scientific | 2025 |
| LS Painting & Decorating Services Ltd | Construction | 2021 |
| LSW Consultancy Services Ltd | Extraterritorial | 2017 |
| Luach Limited | Professional & scientific | 2015 |
| Luca Poian Forms Limited | Professional & scientific | 2019 |
| Lucenvia Advisory Ltd | Professional & scientific | 2025 |
| Lucie White & Company Limited | Real estate | 2007 |
| Lucille Fletcher Limited | Professional & scientific | 2026 |
| Lucinda Dalton Gallery Ltd | Wholesale & retail | 2024 |
| Lucjac Limited | Professional & scientific | 2022 |
| Lucy Challenger Ltd | Professional & scientific | 2013 |
| Lucy Freeland Consulting Limited | Professional & scientific | 2019 |
| Ludlow and Sons Limited | Real estate | 2025 |
| Lujan Design Ltd | Professional & scientific | 2017 |
| Lulu International UK Ltd | Extraterritorial | 2015 |
| Lumii Energytech Ltd | Information & communication | 2025 |
| Luminink Publishing Ltd | Information & communication | 2025 |
| Luminos Fund (UK) | Education | 2025 |
| Lunix Ltd | Construction | 2025 |
| Lush Love Limited | Manufacturing | 2026 |
| Lussano Ltd | Wholesale & retail | 2025 |
| Luuk Technologies Ltd | Information & communication | 2026 |
| Luxe by Property Ltd | Hospitality | 2024 |
| Luxe Interiors Design Ltd | Construction | 2024 |
| Luxe White Cleaners Limited | Other services | 2026 |
| Luxford Holdings Limited | Financial services | 2024 |
| Luxgolf Ltd | Other services | 2024 |
| Lvlogics UK Limited | Professional & scientific | 2020 |
| LW Properties Surrey Limited | Real estate | 1999 |
| LWS Interior Solutions Ltd | Wholesale & retail | 2000 |
| LWS Quartz & Granite Southwest Ltd | Manufacturing | 2019 |
| Lygon Holding Limited | Financial services | 2020 |
| Lygon Limited | Real estate | 2020 |
| Lygon Real Estate Limited | Real estate | 2024 |
| Lyric Dance School Haringey Ltd | Education | 2022 |
| Lyric Dance School Kingston Ltd | Education | 2022 |
| Lyric Dance School Ltd | Education | 2016 |
| Lyric Dance School Newham Ltd | Education | 2022 |
| Lytton Homes (NO. 1) Limited | Construction | 2021 |
| Lytton Homes (NO. 2) Limited | Construction | 2021 |
| Lytton Homes Holding Limited | Construction | 2021 |
| M & M Properties Management Ltd | Real estate | 2020 |
| M & N Corporate Services Limited | Professional & scientific | 2006 |
| M & N Group Limited | Professional & scientific | 1975 |
| M & N Secretaries Limited | Professional & scientific | 1999 |
| M & T Professional Taxi Limited | Transport & logistics | 2024 |
| M a K Builders Limited | Construction | 2016 |
| M Hero Management Ltd | Professional & scientific | 2025 |
| M J Harrison Ltd | Professional & scientific | 2018 |
| M K L Jennings P S Limited | Real estate | 2019 |
| M Logistics Limited | Transport & logistics | 2013 |
| M Recruitment Limited | Administrative & support | 2019 |
| M Ryan Cardiology Ltd | Health & social care | 2025 |
| M S Daniel Ltd | Professional & scientific | 2025 |
| M Square Design & Sourcing Co., Limited | Wholesale & retail | 2024 |
| M&B Removals Ltd | Construction | 2022 |
| M&M2 Investments Limited | Real estate | 2025 |
| M&N Nominees Limited | Professional & scientific | 1999 |
| M&V Property Limited | Real estate | 2018 |
| M. Hughes Properties Ltd | Administrative & support | 2016 |
| M.A.D.Records LLP | | 2022 |
| M.Caracalla Ltd | Transport & logistics | 2025 |
| M.G. Cycles - Bicycle Specialist Ltd | Manufacturing | 2023 |
| M3 Plus Company Limited | Real estate | 2023 |
| MA First UK Limited | Professional & scientific | 2025 |
| MA Propco 50 Limited | Real estate | 2017 |
| Macassar Properties Limited | Real estate | 2017 |
| Macdonald-Capstick Ltd | Professional & scientific | 2019 |
| Machine Automation Limited | Manufacturing | 2004 |
| Macsao Consulting Ltd | Information & communication | 2018 |
| Macura Homes Ltd | Real estate | 2017 |
| MAD London Limited | Wholesale & retail | 2017 |
| Madhumukti Limited | Wholesale & retail | 2025 |
| Mado SR Limited | Wholesale & retail | 2025 |
| MAE Productions Limited | Administrative & support | 2015 |
| Maervo Ltd | Information & communication | 2016 |
| Mafa Limited | Real estate | 2019 |
| Mafrouz Limited | Real estate | 2020 |
| Magedreams Ltd | Information & communication | 2024 |
| Magellan Consulting Limited | Administrative & support | 1997 |