| Luvmydog Limited | Administrative & support | 2010 |
| Luxe Suite Inn Ltd | Real estate | 2024 |
| Luxury Lush Limited | Other services | 2022 |
| LVG Locket Limited | Administrative & support | 2022 |
| LW6 Developments Ltd | Real estate | 2024 |
| LYE PO Ltd | Transport & logistics | 2026 |
| Lyndale Estates Maintenance Limited | Administrative & support | 2007 |
| M & J Property Group Limited | Real estate | 2023 |
| M & J Utilities Ltd | Construction | 2022 |
| M & L Butts Extensions Limited | Construction | 2025 |
| M & N Meats Ltd | Wholesale & retail | 2002 |
| M G Shopfronts Limited | Construction | 2003 |
| M Glazzard Education Ltd | Education | 2019 |
| M Homer Services Limited | Professional & scientific | 2013 |
| M R Fish Imports Ltd | Wholesale & retail | 2025 |
| M Wellings Engineering Limited | Professional & scientific | 2023 |
| M&C Quality Building Limited | Construction | 2022 |
| M&Ch Consulting Ltd | Professional & scientific | 2020 |
| M&M Brothers Store Limited | Wholesale & retail | 2025 |
| M&M Healthcare Group Limited | Health & social care | 2026 |
| M. Golunski & Co., Limited | Wholesale & retail | 1978 |
| M. J. Grainger & Co Ltd | Professional & scientific | 2015 |
| M. Pitchford Holdings Limited | Manufacturing | 1989 |
| M.A. Construction Services Limited | Construction | 2007 |
| M.A.T.E. Interiors Ltd | Construction | 2010 |
| M.C.B.C. Commercial Limited | Construction | 2017 |
| M.C.B.C. Holdings Limited | Financial services | 2017 |
| M.D Taylor Holdings Limited | Real estate | 2025 |
| M.I.F. Filters Limited | Extraterritorial | 2004 |
| M3 Football Limited | Arts & recreation | 2021 |
| Mace Security Ltd | Administrative & support | 2018 |
| Machine Spares Limited | Wholesale & retail | 2001 |
| Machinex Solutions Limited | Professional & scientific | 2010 |
| MAD Ferrett Ltd | Wholesale & retail | 2017 |
| Maddison BL Consultancy Ltd | Information & communication | 2024 |
| Maddison BL Holdings Ltd | Financial services | 2026 |
| Maddison BL Management Ltd | Real estate | 2021 |
| Madiha Properties Ltd | Real estate | 2024 |
| Madni Express Ltd | Hospitality | 2021 |
| Maghoma Properties Limited | Real estate | 2025 |
| Magna Property Ltd | Real estate | 2020 |
| Magnum Industries Europe Limited | Administrative & support | 2001 |
| Magnum Venus Products Europe Limited | Extraterritorial | 2023 |
| Mahan MK Limited | Hospitality | 2023 |
| Majorca Beach Rugby Limited | Professional & scientific | 2011 |
| Majujo Contract Solutions Limited | Information & communication | 2017 |
| MAK (Worcestershire) Ltd | Construction | 2026 |
| Mala Build and Construct Ltd | Construction | 2021 |
| Male Family Group Limited | Arts & recreation | 2020 |
| Malik Group 247 Ltd | Wholesale & retail | 2024 |
| Mamo MBS Limited | Hospitality | 2016 |
| Mancave Limited | Extraterritorial | 2022 |
| Mandd 2020 Holdings Limited | Financial services | 2021 |
| Mani's Bar & Grill Limited | Hospitality | 2018 |
| Mannering Consultants Limited | Other services | 2018 |
| Manor Motor Service Centre Limited | Wholesale & retail | 2022 |
| MAP Digital Ltd | Information & communication | 2026 |
| MAP Engineering (Wednesbury) Ltd | Construction | 2003 |
| Mapara Limited | Wholesale & retail | 2020 |
| Mapleview Estates Ltd | Real estate | 2023 |
| Marble Software Limited | Information & communication | 2020 |
| March GAS Limited | Construction | 2012 |
| Marcus Investments Limited | Construction | 2014 |
| Mario's Food Ltd | Hospitality | 2023 |
| Mark Connolly Building Contractors Limited | Construction | 2016 |
| Mark Sinclair Ltd | Professional & scientific | 2023 |
| Mark’S Honest Autos Ltd | Wholesale & retail | 2026 |
| Mars Transport Services Ltd | Transport & logistics | 2025 |
| Mars Waste Management Ltd | Water & waste | 2024 |
| Marsarril Estates Limited | Construction | 2025 |
| Marsh Scaffold Ltd | Construction | 2025 |
| Martha Thomas Ltd | Arts & recreation | 2024 |
| Martin Lukeman Darts Limited | Arts & recreation | 2024 |
| Mason Metals 2025 Ltd | Financial services | 2025 |
| Mastertrade Supplies Limited | Wholesale & retail | 2007 |
| Mastro Developments Limited | Real estate | 2018 |
| Matcha Nojo Ltd | Hospitality | 2025 |
| Materials-Tech Limited | Professional & scientific | 2022 |
| Matrix Trades and Labour Ltd | Construction | 2026 |
| Matsuzaka Properties Limited | Real estate | 2021 |
| Matton Properties Limited | Real estate | 2025 |
| Maverick Property JK Limited | Real estate | 2022 |
| MAX Utility Services Limited | Administrative & support | 2023 |
| MAX Utility Solutions Limited | Administrative & support | 2025 |
| Maycroft Management Limited | Professional & scientific | 2023 |
| Mayfair Co (England) Limited | Wholesale & retail | 2023 |
| Mayfair Invest Limited | Real estate | 2020 |
| Mayfair Petroleum Ltd | Wholesale & retail | 2023 |
| MAZ Pacheco Limited | Arts & recreation | 2023 |
| MBC Promotions Group Limited | Households | 2016 |
| MBC Promotions Limited | Other services | 2002 |
| MBM Fleet Services Limited | Transport & logistics | 2026 |
| MBM Trailers Limited | Manufacturing | 2024 |
| MBS Lettings Ltd | Real estate | 2017 |
| MCB Financial Limited | Financial services | 2007 |
| MCB Financial Planning Limited | Financial services | 2007 |
| Mccarthy Betts Holdings Limited | Financial services | 2023 |
| Mccarthy Betts Property Limited | Real estate | 2023 |
| Mcfarlane Capital Ltd | Financial services | 2019 |
| Mcgilp Properties Limited | Real estate | 2021 |