| London Masonry Surfaces Limited | Construction | 2021 |
| London PT Studio Limited | Administrative & support | 2021 |
| London River Boats Limited | Administrative & support | 2022 |
| London School of Education and Management Limited | Education | 2016 |
| London Skin Specialists Ltd | Administrative & support | 2019 |
| London Taxi Cabs Limited | Transport & logistics | 2010 |
| London Vision Property Limited | Households | 2013 |
| Lonely Creatures Network Ltd | Wholesale & retail | 2022 |
| Longlands Properties Ltd | Construction | 2021 |
| Loop Light & Power Limited | Construction | 2016 |
| Lords Construction Limited | Administrative & support | 2017 |
| Lotom Ltd | Real estate | 2025 |
| Lotto Club Lotto Ltd | Other services | 2011 |
| Lotus Aesthetics Professional Ltd | Real estate | 2020 |
| Louis Rose Ltd | Professional & scientific | 2025 |
| Love Nails (Blackfen) Limited | Other services | 2022 |
| Love on the Inside Ltd | Extraterritorial | 2026 |
| Love Your Back Osteopathy Limited | Health & social care | 2018 |
| Lovelace Voice Consulting Ltd | Information & communication | 2019 |
| Loveland Properties (London) Ltd | Administrative & support | 2007 |
| LOW Cool Refrigeration Ltd | Construction | 2022 |
| Lowe Group Limited | Construction | 2017 |
| Lowkast Carbon Intelligence Ltd | Information & communication | 2025 |
| Loxley Gaiger Limited | Information & communication | 2016 |
| Loyaldene Limited | | 1991 |
| Lp’S Secure Services Ltd | Information & communication | 2020 |
| LR-L48 Limited | Other services | 2018 |
| LRS Testing Limited | Construction | 2007 |
| LSB Interiors Ltd | Construction | 2019 |
| Lsbl Retail Limited | Wholesale & retail | 2024 |
| LSJ Services Ltd | Construction | 2021 |
| LSK 77 Limited | Financial services | 2025 |
| Lspm Construction Limited | Construction | 2024 |
| Lsts Ltd | Administrative & support | 2021 |
| LT Building Services Ltd | Administrative & support | 2022 |
| LT Business Consultancy Ltd | Administrative & support | 2023 |
| LTA Consultancy Limited | Professional & scientific | 2020 |
| LTB Consultancy Ltd | Professional & scientific | 2024 |
| LTL Heritage Mart Ltd | Wholesale & retail | 2025 |
| Luckypants.Com Limited | Professional & scientific | 2003 |
| Lucmos Ltd | Professional & scientific | 2012 |
| Lucy Canty Projects Ltd | Professional & scientific | 2023 |
| Lucy Day Coaching Limited | Administrative & support | 2020 |
| Lucy&Sam Limited | Wholesale & retail | 2011 |
| Luke Adlam Limited | Administrative & support | 2022 |
| Luke C Grey Estate Agents Ltd | Administrative & support | 2024 |
| Lulworth Limited | Households | 2013 |
| Lumen Software Limited | Wholesale & retail | 2019 |
| Lumi Skin London Ltd | Other services | 2023 |
| Lumina Lighting Limited | Wholesale & retail | 2012 |
| Lumos Inc Ltd | Real estate | 2023 |
| Luoana Ltd | Construction | 2016 |
| Lupine 42 Ltd | Information & communication | 2025 |
| Lush Beauty Lounge Limited | Other services | 2018 |
| Lushi Builder’S & Maintenance Ltd | Construction | 2024 |
| Lw-Aw Limited | Manufacturing | 2013 |
| LWP Refurbishment Ltd | Construction | 2015 |
| LY Housing Limited | Real estate | 2026 |
| LY Property Management Ltd | Real estate | 2024 |
| M & M Electrical Building Services London Limited | Construction | 2015 |
| M & R Security Limited | Administrative & support | 2015 |
| M Adie Fire & Security Ltd | Administrative & support | 2018 |
| M and D Alflatt Family Ventures Limited | Financial services | 2025 |
| M and M Premier Services Ltd | Water & waste | 2025 |
| M Brothers Limited | Information & communication | 2015 |
| M C Reed Limited | Administrative & support | 2021 |
| M C Technicians Ltd | Construction | 2001 |
| M Hyland Electrical Services Limited | Construction | 2019 |
| M J B Electrics Limited | Construction | 2003 |
| M J Carpentry South East Limited | Construction | 2021 |
| M J Fruit Farms Limited | Other services | 1993 |
| M J Rock Holdings Ltd | Real estate | 2019 |
| M O'Brien Limited | Administrative & support | 2012 |
| M Reynolds Electrical Ltd | Construction | 2018 |
| M Reynolds Electrical Services Ltd | Construction | 2024 |
| M&C H Properties Ltd | Real estate | 2016 |
| M&T 2025 Limited | Administrative & support | 2025 |
| M&T Bradley Services Ltd | Construction | 2021 |
| M.A Publishing Ltd. | Professional & scientific | 2013 |
| M.A.C Tree Care Ltd | Agriculture & fishing | 2021 |
| M.E.E Projects Management Limited | Construction | 2026 |
| M.H.J. Limited | Professional & scientific | 1979 |
| M2M Car Sales Limited | Wholesale & retail | 2025 |
| M2RADIO Limited | Information & communication | 2016 |
| MA Catering Ltd | Wholesale & retail | 2018 |
| Macca Consulting Solutions Limited | Administrative & support | 2022 |
| Maceys Estates Limited | Real estate | 2010 |
| Machray Consultancy Services Ltd | Health & social care | 2024 |
| Macka Removals Ltd | Education | 2019 |
| MAD Electrical Ltd | Construction | 2026 |
| Madeira Park Residents Association Limited | Administrative & support | 1982 |
| Madosh Ltd | Real estate | 2024 |
| Magnolia Hairdressing Ltd | Other services | 2020 |
| Magnum & Able Limited | Professional & scientific | 2011 |
| Magnum Commercial Limited | Construction | 2015 |
| Magpie B.M.S. Services Limited | Construction | 1994 |
| Main Road Place Ltd | Construction | 2025 |
| Main Road Space Limited | Construction | 2024 |
| Mainsflow Plumbing & Heating Ltd | Administrative & support | 2022 |
| Maintenance & Environmental Services Limited | Administrative & support | 2016 |