| M B Connected Investments Ltd | Real estate | 2024 |
| M B Connected Ltd | Professional & scientific | 2023 |
| M H C Limited | Other services | 2002 |
| M I Workwear Ltd | Wholesale & retail | 2017 |
| M J P Carpentry Services Limited | Construction | 2000 |
| M Jolley Consultancy Limited | Administrative & support | 2014 |
| M P Leisure Ltd | Hospitality | 2003 |
| M S Norbury Ltd | Construction | 2011 |
| M Signs UK Limited | Professional & scientific | 2004 |
| M&G Global UK Limited | Real estate | 2015 |
| M&G IT Services Limited | Information & communication | 2023 |
| M&M Group ( Midlands) Limited | Financial services | 2020 |
| M&M Property Innovations Limited | Construction | 2020 |
| M.D Thermal Ltd | Construction | 2022 |
| M.E Ward Limited | Professional & scientific | 2024 |
| M.J.P Eco Energy Limited | Wholesale & retail | 2015 |
| M.R.H. Autos Limited | Wholesale & retail | 2003 |
| M.T. Developments Limited | Professional & scientific | 1972 |
| M2 Flooring Services Ltd | Construction | 2021 |
| M2E Ltd | Professional & scientific | 2015 |
| MAC Building and Roofing Limited | Construction | 2021 |
| Macbeattie Recruitment Ltd | Administrative & support | 2009 |
| Machin & Palfreyman Ltd | Manufacturing | 2003 |
| Maclennan Ltd | Professional & scientific | 2000 |
| Macquis Build Limited | Construction | 2022 |
| Made by Leah Limited | Manufacturing | 2016 |
| Made to BE Personalised Ltd | Wholesale & retail | 2023 |
| Madebymandyukcrafts Ltd | Wholesale & retail | 2021 |
| Madeth Ltd | Transport & logistics | 2019 |
| MAG Services Ltd | Transport & logistics | 2018 |
| Magic Lantern Media Limited | Information & communication | 2019 |
| MAH Education Limited | Arts & recreation | 2020 |
| MAH Health Industries Limited | Education | 2025 |
| Maid in Stratford Ltd | Administrative & support | 2016 |
| Mainpride Loft Conversions Limited | Construction | 2012 |
| Major Curry Affair Lichfield Ltd | Hospitality | 2024 |
| Mako Asset Management Ltd | Professional & scientific | 2023 |
| Malan Holdings Ltd | Real estate | 2023 |
| Malini Bala Limited | Health & social care | 2013 |
| Malvern Rise Management Company Limited | Households | 2017 |
| Manchester Martial Arts Ltd | Arts & recreation | 2024 |
| Maney Project Services Ltd | Professional & scientific | 2020 |
| Mangia Mangia Lichfield Ltd | Hospitality | 2025 |
| Mankind (Lichfield) Ltd | Wholesale & retail | 2013 |
| Mann Inc Ltd | Wholesale & retail | 2018 |
| Mann Medical Ltd | Health & social care | 2021 |
| Manoir Property Staging & Interiors Ltd | Construction | 2025 |
| Manor Refrigeration (Midlands) Limited | Manufacturing | 2015 |
| Manor Taxi Ltd | Transport & logistics | 2023 |
| Manso Joinery Limited | Manufacturing | 2021 |
| Manufacturing Production Solutions Limited | Administrative & support | 2005 |
| Mapa Spontex UK Limited | Wholesale & retail | 1978 |
| Maple Brook Projects Ltd | Construction | 2021 |
| Mara RC Ltd | Professional & scientific | 2023 |
| Marchall Holdings Limited | Extraterritorial | 2012 |
| Marchington Investments Limited | Real estate | 2012 |
| Marcoria UK Ltd | Information & communication | 2024 |
| Margot & Brook Ltd | Professional & scientific | 2025 |
| Mark Ellison Limited | Construction | 2003 |
| Mark Hands Holdings Limited | Administrative & support | 2024 |
| Mark Horton Transport Limited | Transport & logistics | 2016 |
| Mark J Forbes Ltd | Professional & scientific | 2026 |
| Mark Reynolds Financial Planning Limited | Financial services | 2007 |
| Mark Simmons Heating & Plumbing Limited | Construction | 2004 |
| Mark Starkey Properties Limited | Real estate | 2008 |
| Marken Heating & Air Conditioning Limited | Energy | 2012 |
| Marklew Productions Limited | Administrative & support | 2018 |
| Marl Group Ltd | Professional & scientific | 2018 |
| Marsh Property Limited | Real estate | 2004 |
| Marshallmanagement Ltd | Professional & scientific | 2024 |
| Marson and Ridge Ltd | Hospitality | 2024 |
| Marson Bathrooms Ltd | Construction | 2025 |
| Martin & Mcbride Limited | Professional & scientific | 2015 |
| Martin Hart Interiors Limited | Extraterritorial | 2008 |
| Martin Hart Shopfitting Limited | Construction | 2005 |
| Martin Heston Equipment Limited | Administrative & support | 1981 |
| Martincadwallader Ltd | Professional & scientific | 2024 |
| Martyn Proctor Ltd | Professional & scientific | 2017 |
| Mary Meacham Ltd | Professional & scientific | 2013 |
| Maryfields (Midlands) Limited | Real estate | 2026 |
| Masonry Solutions (Midlands) Ltd | Manufacturing | 2013 |
| Masterclass Events Limited | Hospitality | 2024 |
| Matrius Property Investments Limited | Real estate | 2020 |
| Matt Adams Limited | Construction | 2006 |
| Matt:E Ltd | Manufacturing | 2007 |
| Matthew Preston Photography Ltd | Professional & scientific | 2018 |
| Maurice & Co Property Limited | Real estate | 2025 |
| Mavericks Football Club C.I.C. | Arts & recreation | 2023 |
| Mawera (UK) Limited | Manufacturing | 1982 |
| Maximise Brands Limited | Wholesale & retail | 2019 |
| Maximum Health Ltd | Arts & recreation | 2024 |
| Maximum Motor Sport Limited | Arts & recreation | 2012 |
| Maxwell Safety Limited | Professional & scientific | 2022 |
| May's Walk Management Limited | Real estate | 1999 |
| Mayarch Limited | Real estate | 2017 |
| Mayfair Properties (Midlands) Ltd | Real estate | 2006 |
| Mayfair Tea Limited | Wholesale & retail | 2025 |
| Mayo Music Limited | Information & communication | 2015 |
| Maypet Ltd | Construction | 2016 |
| Mayyk Limited | Information & communication | 2023 |