| Malvern Court Management Ltd | Real estate | 1985 |
| Malvern Hill House (Cheltenham) Residents Association Limited | Households | 1982 |
| Malvern Place Management Company Limited | Households | 1989 |
| Malvern Road Management Ltd | Households | 1988 |
| Malvern View Ltd | Hospitality | 2022 |
| MAM Property Developers Ltd | Construction | 2026 |
| Mama MUM Ltd | Administrative & support | 2024 |
| Mamas and Wiggles Ltd | Wholesale & retail | 2020 |
| Managed Intelligence Ltd | Professional & scientific | 2025 |
| Managers Operating Guide Limited | Education | 2024 |
| Managing IT Projects Ltd | Information & communication | 2000 |
| Managing Success Ltd | Real estate | 2018 |
| Manchester and Provincial Car Parks Limited | Transport & logistics | 1987 |
| Manchester Park Management Company Limited | Households | 1989 |
| Mandeleo Partners LLP | | 2020 |
| Mander Hall Academy Ltd | Arts & recreation | 2018 |
| Manderley Davlor Ltd | Real estate | 2022 |
| Mandm Walton Ltd | Professional & scientific | 2019 |
| Manfield Mortgage Services Limited | Financial services | 2005 |
| Mangnalls Architecture Ltd | Professional & scientific | 2020 |
| Manor Barn Kitchen Ltd | Hospitality | 2025 |
| Manor Brun LLP | | 2009 |
| Manor Ground Properties Limited | Real estate | 2017 |
| Manor Homes (UK) Ltd | Real estate | 2014 |
| Manor Park Management (2016) Limited | Extraterritorial | 2016 |
| Manor Park Management Limited | Real estate | 1988 |
| Manor Shark | Other services | 2020 |
| Mansell Heritage Investments | Professional & scientific | 2025 |
| Mansim Limited | Health & social care | 2007 |
| Mansion House (Prestbury) Management Limited | Households | 2003 |
| Manton Executives Limited | Administrative & support | 2021 |
| Manton Property Holdings Ltd | Real estate | 2024 |
| Mantra IT Solutions Limited | Information & communication | 2015 |
| Mantra Marketing Limited | Administrative & support | 2000 |
| Manuka Direct Ltd | Wholesale & retail | 2018 |
| Many Hats Creative Limited | Professional & scientific | 2016 |
| Maple (234) Limited | Households | 2004 |
| Maple (279) Limited | Households | 2006 |
| Maple (306) Limited | Households | 2007 |
| Maple (309) Limited | Households | 2007 |
| Maple (366) Limited | Households | 2012 |
| Maple (388) Limited | Households | 2014 |
| Maple (447) Limited | Households | 2019 |
| Maple House Property Ltd | Real estate | 2024 |
| Maple Leaf Property Consultants Limited | Real estate | 2004 |
| Maple Rock Design Limited | Professional & scientific | 2016 |
| Mapm Limited | Wholesale & retail | 2014 |
| Mapps Place Therapy Ltd | Professional & scientific | 2021 |
| Marbid Partnership Limited | Wholesale & retail | 1992 |
| Marble Flame Consulting Limited | Professional & scientific | 2009 |
| Marcello Music Limited | Arts & recreation | 2023 |
| Marchant Group Ltd | Financial services | 2017 |
| Marches Biogas Limited | Administrative & support | 2009 |
| Marchmont Property Services Ltd | Real estate | 2018 |
| Marco Salon Ltd | Other services | 2026 |
| Marco&Luca Limited | Hospitality | 2025 |
| Marcus Bergin Gardening Limited | Administrative & support | 2024 |
| Marcus Hawtin Builders Limited | Construction | 2009 |
| Marcus Homes Limited | Construction | 2009 |
| Mardies Contract Services Ltd | Construction | 2019 |
| Mariam Properties & Investments Ltd | Real estate | 2023 |
| Marich Limited | Real estate | 2018 |
| Marine JET Power Limited | Manufacturing | 1996 |
| Marisco Limited | Real estate | 1998 |
| Marjuze Ltd | Professional & scientific | 2019 |
| Mark Banwell Chimneys & Stoves Ltd | Administrative & support | 2020 |
| Mark Casey Limited | Construction | 2012 |
| Mark Edgeworth (Auto-Electrical) Ltd | Wholesale & retail | 2003 |
| Mark Hayward Carpentry Ltd | Construction | 2017 |
| Mark Henderson Lighting Design Limited | Administrative & support | 2011 |
| Mark Holland (Cheltenham) Limited | Professional & scientific | 2008 |
| Mark Latchford Screen and Digital Print Limited | Manufacturing | 2012 |
| Mark LEA Interior Designs Limited | Wholesale & retail | 2014 |
| Mark Lewis Design Limited | Professional & scientific | 2008 |
| Mark Lutman Consultant Ltd | Professional & scientific | 2013 |
| Mark Lynch Limited | Information & communication | 2006 |
| Mark Prance Ltd | Financial services | 2013 |
| Mark Price Consulting Ltd | Professional & scientific | 2022 |
| Mark Solway Ltd | Professional & scientific | 2024 |
| Mark Weaver Design Ltd | Professional & scientific | 2025 |
| Mark Young Design Ltd | Professional & scientific | 2016 |
| Markadia Limited | Professional & scientific | 2016 |
| Marketing & Development (Holdings) Limited | Real estate | 1972 |
| Marketing Dimensions Limited | Professional & scientific | 2004 |
| Marketing Effectiveness Consultancy Ltd | Professional & scientific | 2026 |
| Marketing Partnership Group Limited | Professional & scientific | 2017 |
| Marketing Support Services Limited | Administrative & support | 1989 |
| Marketing Yeah Ltd | Professional & scientific | 2018 |
| Marlborough Land Developments Limited | Construction | 1991 |
| Marle Rise (Cheltenham) Limited | Real estate | 2008 |
| Marlow First Management Limited | Information & communication | 1998 |
| Marlows Commercial Cleaning Ltd | Administrative & support | 2025 |
| Marmalade Fine Fragrance Ltd | Manufacturing | 2011 |
| Marqeta UK Ltd | Other services | 2018 |
| Marque Motors Limited | Wholesale & retail | 2016 |
| Marsh Residencies Limited | Real estate | 2020 |
| Marshall & Marshall Accountants Ltd | Professional & scientific | 2025 |
| Marshall Enterprises (Lichfield) Ltd | Real estate | 2002 |
| Marshall House (Residents Association) Limited | Households | 1980 |
| Marshall Rare Books Limited | Wholesale & retail | 2023 |