| LSA Retail Telscombe Ltd | Wholesale & retail | 2016 |
| LSC Accounts Limited | Professional & scientific | 2025 |
| LSR Building Solutions Ltd | Construction | 2024 |
| LST Foods Ltd | Hospitality | 2023 |
| LTS Grab Hire Ltd | Water & waste | 2018 |
| LTY Group Ltd | Construction | 2025 |
| Luardos Mexican Street Food Limited | Hospitality | 2023 |
| Lucid Picturehouse Ltd | Information & communication | 2020 |
| Lucky Cat Global Ltd | Wholesale & retail | 2024 |
| Lucky Rooms UK Ltd | Professional & scientific | 2025 |
| Luisa.Creating & Inspiring by Design. Ltd | Professional & scientific | 2025 |
| Luli Limited | Administrative & support | 2006 |
| Luma Construction Ltd | Construction | 2018 |
| Lumaera Care Limited | Health & social care | 2026 |
| Lumalea Ltd | Construction | 2026 |
| Lumi B Limited | Construction | 2016 |
| Lumi Nails Limited | Other services | 2026 |
| Lumiere Children's Homes Limited | Real estate | 2025 |
| Luminis Property Limited | Real estate | 2025 |
| Luna AID UK Limited | Wholesale & retail | 2024 |
| Lunova Heating & Plumbing Ltd | Construction | 2025 |
| Lush General Services Limited | Administrative & support | 2018 |
| Luxe Property Investments Ltd | Real estate | 2022 |
| Luxe Travel Solution Limited | Transport & logistics | 2025 |
| Luxman MED Ltd | Health & social care | 2014 |
| Luxmi Service Ltd | Administrative & support | 2024 |
| Luxnails DH Ltd | Other services | 2025 |
| Luxury Country Cottages Ltd | Real estate | 2023 |
| Luxury Hand Car Wash Ltd | Administrative & support | 2024 |
| Luxury Party Favours Limited | Real estate | 2017 |
| Luxury Property & Lettings Ltd | Real estate | 2024 |
| Luxury Sports Cars Ltd | Wholesale & retail | 2022 |
| LUZ Ltd | Health & social care | 2026 |
| Lwazi Home Care Limited | Health & social care | 2022 |
| Lwzk Creative Ltd | Professional & scientific | 2023 |
| Lydia-Claire Halliday Consultancy Ltd | Professional & scientific | 2020 |
| LYE Service Limited | Wholesale & retail | 2004 |
| Lyme Electrical Ltd | Construction | 2006 |
| Lynn Howard Ltd | Professional & scientific | 2021 |
| Lyons Luxury Retail Ltd | Wholesale & retail | 2023 |
| Lysaro Home Limited | Wholesale & retail | 2025 |
| M & C Construction Surrey Ltd | Construction | 2014 |
| M & D Galetti Limited | Information & communication | 2013 |
| M & D Rise Healthcare Limited | Health & social care | 2021 |
| M & G Stubbs Limited | Administrative & support | 2013 |
| M & LA Vida Ltd | Extraterritorial | 2022 |
| M & N Homes Ltd | Real estate | 2018 |
| M & S Site Services Limited | Construction | 2008 |
| M a Chiro Limited | Health & social care | 2008 |
| M B E Associates Ltd | Professional & scientific | 2013 |
| M C Electrical (UK) Ltd | Construction | 2003 |
| M Davis Studio Limited | Other services | 2024 |
| M Equine Limited | Other services | 2021 |
| M Healy Haulage Ltd | Manufacturing | 2018 |
| M I Dabrowski Ltd | Construction | 2014 |
| M J D M Ltd | Construction | 2010 |
| M J Davada Ltd | Health & social care | 2014 |
| M K D Scaffolding Services Limited | Construction | 2015 |
| M Khan Consultants Ltd | Health & social care | 2020 |
| M Lansdown Consultancy Limited | Professional & scientific | 2020 |
| M M Contractors London Limited | Administrative & support | 2011 |
| M M H Davies Ltd | Administrative & support | 2024 |
| M P Assessments Limited | Administrative & support | 2010 |
| M Purcell Services Limited | Wholesale & retail | 2014 |
| M Q Food Services Ltd | Hospitality | 2024 |
| M S Salim Consultoria Ltd | Transport & logistics | 2025 |
| M Todd Electrical Limited | Construction | 2025 |
| M&Az Ltd | Construction | 2021 |
| M&D Black Consulting Limited | Professional & scientific | 2014 |
| M&M Nabha Ltd | Real estate | 2025 |
| M&M Wellness Ltd | Health & social care | 2026 |
| M&S Construction Limited | Construction | 2018 |
| M&S OFF Licence Ltd | Wholesale & retail | 2025 |
| M&S Services & Contracting Ltd | Real estate | 2017 |
| M-Fabric Collaboration Ltd | Wholesale & retail | 2023 |
| M. Stone & SON Decorators Ltd | Construction | 2021 |
| M.&.J. Contractors Limited | Construction | 2006 |
| M.A. Keen Limited | Real estate | 1965 |
| M.Y.R. Project Management Ltd | Wholesale & retail | 2021 |
| M2 Fibre Ltd | Administrative & support | 2024 |
| M25 Packs Ltd | Wholesale & retail | 2025 |
| M25 Global Ltd | Wholesale & retail | 2018 |
| M2MFIRST Limited | Information & communication | 2018 |
| M4 Data Solutions Limited | Information & communication | 2022 |
| MA House Holdings Ltd | Information & communication | 2019 |
| MA8-THREADS of Unity Ltd | Wholesale & retail | 2024 |
| MAC 2 the Future Limited | Wholesale & retail | 2024 |
| MAC Developments (Cheam) Ltd | Construction | 2014 |
| MAC Developments (Woodcote) Ltd | Construction | 2020 |
| MAC Land Projects Limited | Real estate | 2026 |
| Macaloney Pigeons Ltd | Wholesale & retail | 2024 |
| Macauri Services & Solutions Ltd | Construction | 2022 |
| Mace Davies Associates Limited | Professional & scientific | 2018 |
| MACE3 Ltd | Hospitality | 2015 |
| Macelory Ltd | Health & social care | 2015 |
| Macer Healthcare Limited | Health & social care | 2021 |
| Mackenzie Figurines Limited | Other services | 2012 |
| Mackenzie Property Portfolio Ltd | Real estate | 2025 |
| Macro Sensation Limited | Construction | 2018 |
| Macro-Advisory Limited | Professional & scientific | 2018 |