| Loxton Developments 2 Limited | Real estate | 2024 |
| Loxton Developments 3 Limited | Real estate | 2025 |
| Loxton Developments Limited | Real estate | 1987 |
| LPF Consultancy Limited | Health & social care | 2022 |
| LRM HR Consultancy Limited | Professional & scientific | 2016 |
| LSP Lincoln Road SPV Ltd | Real estate | 2023 |
| Ltcg Business Specialists Ltd | Professional & scientific | 2021 |
| LTR Automation Ltd | Professional & scientific | 2022 |
| Lugh Electrical Ltd | Construction | 2025 |
| Lulah Ltd | Wholesale & retail | 2026 |
| Lumen Services Limited | Information & communication | 1998 |
| Luminara Retreats Ltd | Other services | 2025 |
| Lunicorn Limited | Professional & scientific | 2019 |
| Lunicorn Racing LLP | | 2021 |
| Luppiter Bidco Limited | Financial services | 2022 |
| Luppiter Consortium Limited | Financial services | 2022 |
| Lutum Columbus Limited | Financial services | 2019 |
| LW4P Ltd | Other services | 2025 |
| LYD Beauty Ltd | Other services | 2026 |
| Lydia’Skitchen Ltd | Hospitality | 2025 |
| Lyfta Education Limited | Information & communication | 2019 |
| Lyndcroft Media Limited | Professional & scientific | 2014 |
| Lyra Beauty Ltd | Other services | 2023 |
| LZS (Leamington) Limited | Construction | 2015 |
| M & M Getaways Ltd | Real estate | 2024 |
| M & P Harris Limited | Wholesale & retail | 2015 |
| M & S Connolly Limited | Health & social care | 2009 |
| M a C Heating & Plumbing Limited | Construction | 2024 |
| M Aerospace Unlimited | Professional & scientific | 1953 |
| M Brooks Limited | Professional & scientific | 2011 |
| M Carter Heating & Plumbing Ltd | Construction | 2022 |
| M Chip Investments Limited | Financial services | 2018 |
| M D Building Supplies Ltd | Manufacturing | 2021 |
| M J B Electrical Contractors Ltd | Construction | 2018 |
| M Moseley Limited | Professional & scientific | 2016 |
| M P J Fabrications Ltd | Manufacturing | 2003 |
| M P J Holdings Limited | Financial services | 2017 |
| M R Property (Norfolk) Ltd | Construction | 2022 |
| M S Kays Holdings Limited | Real estate | 2018 |
| M&E Roofing and Building Ltd | Construction | 2019 |
| M&M Immigration Lawyers Ltd | Professional & scientific | 2017 |
| M&S Bespoke Plumbing & Heating Ltd | Other services | 2013 |
| M-Cube Estates Ltd | Real estate | 2025 |
| M-Tech Automotive Solutions Limited | Other services | 2002 |
| M.D.G. Limited | Professional & scientific | 1994 |
| M.J.E.Associates Limited | Financial services | 2012 |
| M.R. Electrical Specialists Ltd | Construction | 2011 |
| M.R. Smart Services Ltd | Professional & scientific | 2018 |
| M1CHA3L Ltd | Wholesale & retail | 2023 |
| M4 CMM Ltd | Professional & scientific | 2024 |
| MA Associates Limited | Professional & scientific | 2018 |
| MA VIE Coaching Limited | Professional & scientific | 2023 |
| Mach 1 Couriers Limited | Transport & logistics | 1984 |
| Machine Tool Investments Ltd | Wholesale & retail | 1969 |
| Macsorley Property Ltd | Real estate | 2025 |
| MAD Caps Consultancy Limited | Information & communication | 2018 |
| Madcowinternet Ltd | Information & communication | 2015 |
| Maddisons of Warwick Limited | Wholesale & retail | 2023 |
| Madimade Limited | Administrative & support | 2013 |
| Madox Square LLP | | 2014 |
| MAF Holdco Ltd | Financial services | 2022 |
| Maffey Associates Limited | Construction | 2010 |
| Maggnetic Health Limited | Health & social care | 2024 |
| Maggnetic Property Limited | Real estate | 2024 |
| Magic Windows Banbury Limited | Wholesale & retail | 2023 |
| Mahzen Wine House Ltd | Wholesale & retail | 2023 |
| MAI Rose Solutions Limited | Professional & scientific | 2016 |
| Mail Boxes ETC. (UK) Limited | Professional & scientific | 1995 |
| Maintmaster Systems Limited | Professional & scientific | 2021 |
| Maison Properties Ltd | Real estate | 2018 |
| Maita Group Ltd | Transport & logistics | 2023 |
| Majestic Engineering Products Ltd | Extraterritorial | 2017 |
| Majestic Motors Limited | Wholesale & retail | 2010 |
| Majestic Motorsport Ltd | Wholesale & retail | 2022 |
| Majestic Storage Group Limited | Transport & logistics | 2024 |
| Majestic Storage Ltd | Transport & logistics | 2018 |
| Majesty Developments Ltd | Construction | 2013 |
| Make an Informed Decision Limited | Professional & scientific | 2010 |
| Make Good Grow CIC | Other services | 2018 |
| Makeitwodr.Co.Uk Limited | Professional & scientific | 2024 |
| Makeitwodr.Com Limited | Professional & scientific | 2024 |
| Making Waves Psychology Ltd. | Education | 2023 |
| Mako IT LAB Limited | Information & communication | 2021 |
| Mali Transport Ltd | Transport & logistics | 2026 |
| Mallory Associates Limited | Professional & scientific | 2018 |
| Malty Limited | Administrative & support | 2013 |
| Malvern View Folly Ltd | Real estate | 2023 |
| Mamd Investments Limited | Financial services | 2024 |
| Management Events Co. U.K. Limited | Administrative & support | 2007 |
| Mander Property and Consultancy Ltd | Real estate | 2023 |
| Maneno Holding Limited | Financial services | 2020 |
| Maneno Limited | Education | 2016 |
| Mannmade Customs Ltd | Wholesale & retail | 2018 |
| Manor Architectural Ceramics Limited | Manufacturing | 1997 |
| Manor House Barns Management Company Limited | Households | 1995 |
| Manor Wealth Management Limited | Financial services | 2024 |
| Manual Magic AI Limited | Information & communication | 2025 |
| Manx (Holdings) Limited | Financial services | 2020 |
| Manx Generics Limited | Wholesale & retail | 2015 |
| Manx Healthcare Limited | Manufacturing | 1994 |