| Ludgershall Homes Ltd | Construction | 2022 |
| Ludlow Specsavers Limited | Wholesale & retail | 2007 |
| Ludlow Visionplus Limited | Wholesale & retail | 2007 |
| Luma Power Limited | Professional & scientific | 2026 |
| Luma Realty Limited | Real estate | 2025 |
| Lumacon Group Limited | Administrative & support | 2020 |
| Lumacon Limited | Professional & scientific | 2019 |
| Lumava Ltd | Professional & scientific | 2022 |
| Lumencord Limited | Wholesale & retail | 2026 |
| Luna Acrobatics and Aerial Arts Ltd | Arts & recreation | 2026 |
| Luna Hotels Limited | Hospitality | 2017 |
| Lunita Properties Limited | Real estate | 2020 |
| Lush Dogs Ltd | Other services | 2019 |
| Lussac Consulting Limited | Professional & scientific | 2014 |
| Luton Exclusive Limited | Real estate | 2023 |
| Luton Specsavers Hearcare Limited | Wholesale & retail | 2012 |
| Luton Visionplus Limited | Wholesale & retail | 1990 |
| Lutterworth Specsavers Limited | Wholesale & retail | 2002 |
| LUX Build Group Ltd | Construction | 2026 |
| LUX Event Interiors Ltd | Administrative & support | 2026 |
| Luxury Nails Fareham Ltd | Other services | 2025 |
| Luxvici Holdings Limited | Professional & scientific | 2023 |
| Luxwood Design Ltd | Manufacturing | 2024 |
| Luxx Bespoke Ltd | Wholesale & retail | 2019 |
| LV Yachting Limited | Administrative & support | 2012 |
| LW Property Services Limited | Construction | 2026 |
| Lyca Homes & Properties Ltd | Real estate | 2023 |
| Lycroft Eggs Limited | Wholesale & retail | 2014 |
| Lymington Boat Makers Ltd | Manufacturing | 1996 |
| Lymington Specsavers Hearcare Limited | Wholesale & retail | 2024 |
| Lymington Specsavers Limited | Wholesale & retail | 2007 |
| Lymington Visionplus Limited | Wholesale & retail | 2007 |
| Lymphara Ltd | Other services | 2025 |
| Lynch Live Commerce Ltd | Wholesale & retail | 2025 |
| Lynq Limited | Information & communication | 1981 |
| Lynx International Limited | Extraterritorial | 1950 |
| Lysses Limited | Hospitality | 2001 |
| Lythe Hill Limited | Hospitality | 2015 |
| M & a Carpentry (Southern) Limited | Construction | 2007 |
| M & D Care (Holdings) Limited | Real estate | 2016 |
| M & D Care Group Limited | Health & social care | 2017 |
| M & D Care Limited | Health & social care | 2007 |
| M & O Transport Limited | Administrative & support | 2016 |
| M a & J Building Contractors Ltd | Construction | 2025 |
| M Core Group Limited | Administrative & support | 2020 |
| M F Landscapes Ltd | Administrative & support | 2022 |
| M Good Holdings Ltd | Administrative & support | 2025 |
| M J Downer Ltd | Construction | 1997 |
| M P Decor Limited | Construction | 2015 |
| M R Associates Properties Limited | Real estate | 2019 |
| M Ramsay Plastering Ltd | Construction | 2014 |
| M Technology Consultants Ltd | Information & communication | 2020 |
| M Y H Trading Limited | Hospitality | 2024 |
| M&C Reid Ltd | Professional & scientific | 2025 |
| M&J B3ST 23 Ltd | Real estate | 2023 |
| M&J Property Lettings Limited | Real estate | 2026 |
| M&M Bioprocess Consultancy Limited | Professional & scientific | 2024 |
| M.A. Wright Ltd | Construction | 1997 |
| M.E Rendering Ltd | Construction | 2020 |
| M.J Cafe Limited | Hospitality | 2016 |
| M.K RGN Ltd | Health & social care | 2018 |
| M.K.T. (Portsmouth) Ltd | Hospitality | 2014 |
| M.K.W. Transport Ltd | Transport & logistics | 2015 |
| M4 Consulting Limited | Construction | 2007 |
| M6 Couriers Ltd | Transport & logistics | 2020 |
| MA14 Properties Ltd | Construction | 2020 |
| Mabc Limited | Professional & scientific | 2019 |
| Mabeo IT Ltd | Information & communication | 2018 |
| MAC and Co Barginland Ltd | Wholesale & retail | 2026 |
| MAC and Co Candy Land Ltd | Wholesale & retail | 2025 |
| MAC DPE Limited | Wholesale & retail | 2015 |
| MAC Shack IT Ltd | Other services | 2008 |
| Macclesfield Specsavers Hearcare Limited | Wholesale & retail | 2022 |
| Macintosh Village Car Park (Management) Limited | Households | 2002 |
| Mackay Buildings Ltd | Hospitality | 2020 |
| Macleod Diagnostic Imaging Ltd | Health & social care | 2026 |
| Macromatics Ltd | Information & communication | 2016 |
| Macwood Ltd | Manufacturing | 2018 |
| Madcat Productions (Hampshire) Ltd | Construction | 2022 |
| Maddison Drew Limited | Real estate | 2023 |
| Maddoxford Lane Management Limited | Households | 2019 |
| Made by ME Crafts Limited | Wholesale & retail | 2014 |
| Made by ME Studio Limited | Arts & recreation | 2019 |
| Madhaus Limited | Information & communication | 2018 |
| MAE & White Lettings Limited | Real estate | 2019 |
| Maebill Civils Limited | Construction | 2020 |
| Maebill Limited | Construction | 2020 |
| Maesteg Specsavers Limited | Wholesale & retail | 2006 |
| Maesteg Visionplus Limited | Wholesale & retail | 2006 |
| Maeva Finance Limited | Financial services | 2025 |
| MAG Sussex Limited | Real estate | 2007 |
| Magamara Ltd | Wholesale & retail | 2023 |
| Magellan Automotive Limited | Wholesale & retail | 2008 |
| Magennis Close (Gosport) Management Limited | Households | 1989 |
| Maggsea Marine Services Ltd | Agriculture & fishing | 2024 |
| Maghull Specsavers Limited | Wholesale & retail | 2016 |
| Magill & Company Limited | Financial services | 1989 |
| Magpie Money UK Limited | Financial services | 2021 |
| Mahmoud Shafii Limited | Professional & scientific | 2025 |
| Maidenhead Specsavers Hearcare Limited | Wholesale & retail | 2012 |