| M Kelly Orthopaedics Ltd | Health & social care | 2013 |
| M L G Homes Ltd | Real estate | 2023 |
| M L Motors (Bristol) Limited | Wholesale & retail | 2009 |
| M M Facilities Management Services Limited | Administrative & support | 2023 |
| M Moore Consulting Limited | Information & communication | 2025 |
| M Newick Limited | Wholesale & retail | 2003 |
| M P Auto Services SW Ltd | Wholesale & retail | 2023 |
| M P Property and Build Limited | Construction | 2016 |
| M R C Estates Ltd | Real estate | 2016 |
| M R Delaney Ltd | Other services | 2013 |
| M R Whitehouse Limited | Health & social care | 2020 |
| M S Budd Electrical Limited | Construction | 2020 |
| M S Painting Contractor Limited | Construction | 2022 |
| M S Truck Ltd | Manufacturing | 2025 |
| M S Ventilation Limited | Manufacturing | 2003 |
| M Sheard Property Ltd | Real estate | 2018 |
| M Solutions Services Ltd | Professional & scientific | 2024 |
| M Somali Ltd | Hospitality | 2015 |
| M Still Catering Limited | Hospitality | 1994 |
| M T Miniatures Ltd | Wholesale & retail | 2010 |
| M T Property Southwest Ltd | Real estate | 2022 |
| M Taylor Electrical Services Limited | Construction | 2018 |
| M Taylor Psychology Ltd | Education | 2025 |
| M Tiley Electrical Limited | Construction | 2003 |
| M W Autos Ltd | Wholesale & retail | 2020 |
| M W Bayfield Limited | Construction | 2005 |
| M W Building Ltd | Construction | 2018 |
| M W Sales Agents Limited | Wholesale & retail | 2021 |
| M Watts Countryside Contracting Limited | Agriculture & fishing | 2017 |
| M White Contracting Ltd | Professional & scientific | 2022 |
| M Wilcox (Electrical Contractors) Limited | Wholesale & retail | 2017 |
| M Wiltshire Builder Limited | Construction | 2018 |
| M Zone Limited | Wholesale & retail | 2025 |
| M&A Advisors Limited | Professional & scientific | 2020 |
| M&A Auto Service Ltd | Wholesale & retail | 2025 |
| M&A Professional Consulting Ltd | Professional & scientific | 2025 |
| M&B Property Rentals Ltd | Real estate | 2026 |
| M&C Groundworks Ltd | Construction | 2026 |
| M&C Scaffolding Ltd | Construction | 2026 |
| M&D Catering Ltd | Hospitality | 2026 |
| M&E Loft & Rendering Limited | Construction | 2026 |
| M&G Beauty Limited | Other services | 2024 |
| M&J Goodwin Ltd | Financial services | 2022 |
| M&L Brown Ltd | Extraterritorial | 2013 |
| M&L Services Cleaning Ltd | Construction | 2025 |
| M&M Agile Solutions Limited | Information & communication | 2017 |
| M&M Bristol Cars Ltd | Wholesale & retail | 2025 |
| M&M Carpentry and Interiors Limited | Manufacturing | 2022 |
| M&M Creative LLP | | 2024 |
| M&M Daughters Limited | Wholesale & retail | 2012 |
| M&M Enterprise T/A the New Inn Ltd | Hospitality | 2018 |
| M&M Houses Limited | Real estate | 2026 |
| M&M Mortgages Limited | Financial services | 2018 |
| M&M Property and Developments (Bristol) Limited | Real estate | 2026 |
| M&N Clothing Ltd | Wholesale & retail | 2019 |
| M&N Property Developments Limited | Construction | 2016 |
| M&N.Building.Roofingsolutions Ltd | Construction | 2024 |
| M&P Indian Limited | Hospitality | 2015 |
| M&P Lettings Limited | Real estate | 2022 |
| M&P Property Consultants LLP | | 2020 |
| M&P Singh Lettings Ltd | Real estate | 2017 |
| M&R Property Ventures Ltd | Administrative & support | 2025 |
| M&R Talent Ltd | Administrative & support | 2023 |
| M&S Properties (Bristol) Limited | Real estate | 2026 |
| M&S Shar Ltd | Information & communication | 2020 |
| M&S Traders (Bristol) Limited | Wholesale & retail | 2019 |
| M&T Hospitality Ltd | Hospitality | 2019 |
| M'Lissa Music Ltd | Other services | 2017 |
| M-Clad Holdings Limited | Financial services | 2024 |
| M-H Engineering Consulting Ltd | Construction | 2023 |
| M-Media Events Ltd | Administrative & support | 2019 |
| M-Tech Electrical Controls Limited | Manufacturing | 2024 |
| M-Tech Fabrication Ltd | Manufacturing | 2025 |
| M. & J. Commercial Avon Limited | Wholesale & retail | 2024 |
| M. & J. Transport Avon Limited | Transport & logistics | 1985 |
| M. B. Air UK Ltd | Construction | 2006 |
| M. Floor Limited | Construction | 2004 |
| M. G. (140) Management Company Limited | Extraterritorial | 1990 |
| M. J. Perring Limited | Professional & scientific | 2005 |
| M. R. Property Services Ltd | Administrative & support | 2015 |
| M. S. Ovens Limited | Agriculture & fishing | 2004 |
| M.A.C.H. Investment Properties Limited | Real estate | 2026 |
| M.A.D. Associates Limited | Wholesale & retail | 2004 |
| M.A.It. Limited | Public administration | 2006 |
| M.A.K.Groundworks Ltd | Construction | 2020 |
| M.A.R Transport Limited | Transport & logistics | 2025 |
| M.A.T. Fire Systems Limited | Administrative & support | 2000 |
| M.B. Frames P.V.C.-U Limited | Manufacturing | 1992 |
| M.D. Building Services Limited | Construction | 1998 |
| M.D. Painting & Decoration Services Ltd | Construction | 2019 |
| M.E Marketing Consultancy Services Limited | Professional & scientific | 2018 |
| M.E.S.K. Electrical Services Limited | Construction | 2006 |
| M.F.W Lettings Limited | Real estate | 2024 |
| M.G Food & Beverage Ltd | Manufacturing | 2016 |
| M.Gee Limited | Wholesale & retail | 2006 |
| M.J. Miles Limited | Information & communication | 2016 |
| M.J. O'Connor (Bristol) Limited | Wholesale & retail | 1966 |
| M.Jakubczyk Trading Investment Ltd | Transport & logistics | 2012 |
| M.L. Screeding & Levelling Solutions Ltd | Construction | 2018 |
| M.O.M Play Space Ltd | Arts & recreation | 2024 |