| MK Reformed Academy Limited | Education | 2024 |
| MK Reformed Edgbaston Limited | Arts & recreation | 2025 |
| MK Reformed Harborne Limited | Arts & recreation | 2025 |
| MK Reformed Knowle Limited | Arts & recreation | 2022 |
| MK Reformed Knutsford Limited | Arts & recreation | 2025 |
| MK Reformed Mere Green Limited | Arts & recreation | 2024 |
| MK Reformed New Street Limited | Arts & recreation | 2025 |
| MK Reformed Stratford Limited | Arts & recreation | 2025 |
| MK Reformed Warwick Limited | Arts & recreation | 2026 |
| MK Tours & Events Limited | Arts & recreation | 2025 |
| ML & KG Services Limited | Professional & scientific | 2016 |
| ML Exterior Cleaning Ltd | Professional & scientific | 2025 |
| MLC Group Holdings Limited | Financial services | 2024 |
| MLC Leisure Limited | Manufacturing | 2022 |
| MLK Constructions Ltd | Construction | 2019 |
| Mlre Limited | Financial services | 2021 |
| Mlwc Holdings Ltd | Professional & scientific | 2016 |
| Mlwc Ltd | Construction | 2014 |
| MLX Media Ltd | Information & communication | 2024 |
| MM & RM Properties Ltd | Real estate | 2017 |
| MM Holding Investments Limited | Professional & scientific | 2025 |
| MM Northwest Development Ltd | Real estate | 2026 |
| MM Watch Co. Limited | Wholesale & retail | 2009 |
| MMB Carpentry Ltd | Construction | 2026 |
| Mmcg Partners Limited | Health & social care | 2016 |
| MMG Developments Plus Ltd | Construction | 2026 |
| MMI Incorporate Limited | Construction | 2012 |
| Mmpa Holding Limited | Financial services | 2025 |
| Mmplogistics Ltd | Transport & logistics | 2025 |
| Mmrb Investments Limited | Real estate | 2024 |
| MN Rahman Limited | Public administration | 2018 |
| MNB Blinds Ltd | Manufacturing | 2025 |
| MNE Investments Limited | Financial services | 2020 |
| MNI Consulting Limited | Administrative & support | 2019 |
| MNT Infotech(Uk) Ltd | Information & communication | 2018 |
| Mnts Estates Limited | Real estate | 2024 |
| MO 2 Go Private Hire Services Ltd | Transport & logistics | 2025 |
| Moat Barn Ltd | Professional & scientific | 2020 |
| Mobcorp Ltd | Information & communication | 2025 |
| Mobile Phone Parts Company Ltd | Wholesale & retail | 2021 |
| Mobile+Care Limited | Wholesale & retail | 2016 |
| Mobilia Stone Limited | Construction | 2025 |
| MOD Events Ltd | Professional & scientific | 2023 |
| Modboxuk.Com Ltd | Wholesale & retail | 2020 |
| Model Advisory Services Ltd | Professional & scientific | 2026 |
| Model Features Limited | Water & waste | 1952 |
| Modern Stoneworks Limited | Construction | 2021 |
| Modius Holdings Limited | Financial services | 2018 |
| Moeez Enterprise Limited | Health & social care | 2014 |
| Moen Holdings Limited | Financial services | 2025 |
| Moghal Locums Ltd | Professional & scientific | 2016 |
| MOH Hanif & Co Ltd | Real estate | 2022 |
| Moita Deliveries Limited | Transport & logistics | 2026 |
| Molaro Properties Ltd | Real estate | 2025 |
| Molequle-On Limited | Wholesale & retail | 2023 |
| Molins Express Limited | Administrative & support | 2013 |
| Molly Lane Gifts Ltd | Wholesale & retail | 2021 |
| Molly the Dog Investments Limited | Administrative & support | 2018 |
| Mollycoddles Doggy Day Care Limited | Other services | 2023 |
| Momentsbydoyle Ltd | Professional & scientific | 2025 |
| Momentum DC Limited | Information & communication | 2015 |
| Monacelle Investments Limited | Financial services | 2026 |
| Monacokool Limited | Administrative & support | 2003 |
| Monaghan Design & Build Limited | Construction | 2019 |
| Monarch Forge Group Ltd | Construction | 2025 |
| Mondian Consultancy Services Ltd | Administrative & support | 2018 |
| Monet Stanford Ltd | Health & social care | 2025 |
| Moneybliss Limited | Professional & scientific | 2021 |
| Monkey Smiles Ltd | Construction | 2022 |
| Monkspath (FMA) Limited | Arts & recreation | 2016 |
| Monkspath Financial Management Limited | Professional & scientific | 2010 |
| Monster and Monster Limited | Information & communication | 2011 |
| Monstermedals Ltd | Administrative & support | 2012 |
| Montague House (Leamington Spa) Management Company Limited | Households | 2002 |
| Montgomery Carpets Limited | Other services | 2001 |
| Montgomery Sharpe Limited | Real estate | 2020 |
| Montvell Ltd. | Manufacturing | 2025 |
| Monty Services Ltd | Health & social care | 2025 |
| Monty's Pharma Ltd | Health & social care | 2021 |
| Monwood Consultants Limited | Professional & scientific | 2026 |
| Mon£Ey Limited | Wholesale & retail | 2018 |
| MOO Social Ltd | Professional & scientific | 2023 |
| Moodlifter Limited | Extraterritorial | 2018 |
| Moody Pearce Holdings Limited | Professional & scientific | 2023 |
| Moody Pearce Limited | Professional & scientific | 2016 |
| Moon Dust Developments Ltd | Information & communication | 2022 |
| Moorcroft Controls Limited | Professional & scientific | 2010 |
| Moorcroft Electrical Limited | Construction | 2004 |
| Moorcroft Switchgear Limited | Manufacturing | 2022 |
| Moorcroft UK Group Limited | Financial services | 2022 |
| Moore Motors Limited | Wholesale & retail | 2000 |
| Moore Property DEV Limited | Real estate | 2025 |
| Moore Property Portfolio Limited | Real estate | 2023 |
| Moorfield Real Estate Ltd | Construction | 2021 |
| Moorgate Asset Administration Limited | Professional & scientific | 2008 |
| Moorgate Loan Servicing Limited | Financial services | 1997 |
| Moosa Shah Holdings Limited | Information & communication | 2025 |
| MOP Heads & Buckets Limited | Administrative & support | 2019 |
| Moraf Holdings UK Ltd | Administrative & support | 2020 |
| Morgan Fitter Limited | Other services | 2005 |