| Moduleco Limited | Construction | 2013 |
| Modus Outcomes Limited | Professional & scientific | 2015 |
| Moft Tranfer Limited | Transport & logistics | 2025 |
| MOH Law LLP | | 2020 |
| Moien Limited | Financial services | 2021 |
| Mole Consulting Ltd | Professional & scientific | 1997 |
| Mollsretail Ltd | Wholesale & retail | 2025 |
| Molly's Chambers Holding Europe Ltd | Wholesale & retail | 2016 |
| Molo Holiday Housekeeping Specialists Ltd | Real estate | 2015 |
| Molyneux Advisory Partners Ltd | Professional & scientific | 2024 |
| Molyneux Ventures Limited | Financial services | 2024 |
| MOMENT3 Limited | Information & communication | 2019 |
| Mona Vale Time-Share Limited | Extraterritorial | 1982 |
| Monatrix Limited | Administrative & support | 2003 |
| Mondeche Limited | Construction | 2022 |
| Monere Projects Limited | Professional & scientific | 2020 |
| Moneybeing Ltd | Information & communication | 2023 |
| Monica Drive Holdings Limited | Administrative & support | 2026 |
| Monkey Puzzle Training & Consultancy Limited | Professional & scientific | 2007 |
| Monkey's Cousin Limited | Professional & scientific | 2012 |
| Monolith Projects Ltd | Real estate | 2017 |
| Monolith Property Ltd | Real estate | 2019 |
| Monster Creative Limited | Arts & recreation | 2001 |
| Mont Blanc 4809 Investments | Professional & scientific | 2024 |
| Montagu West Limited | Professional & scientific | 2013 |
| Montdog Ltd | Manufacturing | 2023 |
| Montpelier Partners Ltd | Administrative & support | 2021 |
| Montpelier Spa Road Management Company Limited | Households | 2008 |
| Montpellier Apartments (Cheltenham) Management Company Limited | Households | 1999 |
| Montpellier Asset Management Limited | Financial services | 2004 |
| Montpellier Barbers Ltd | Other services | 2016 |
| Montpellier Brewing Company Limited | Manufacturing | 2025 |
| Montpellier Caryatids Ltd | Real estate | 2024 |
| Montpellier Court (Cheltenham) Limited | Households | 2004 |
| Montpellier Courtyard Residents Ltd. | Households | 1990 |
| Montpellier Creative Limited | Professional & scientific | 2011 |
| Montpellier Grove (Cheltenham) Management Company Limited | Households | 1998 |
| Montpellier Health Care Limited | Health & social care | 2024 |
| Montpellier House Freehold Limited | Households | 2020 |
| Montpellier House Management Company Limited | Households | 1986 |
| Montpellier House Residents Limited | Hospitality | 1999 |
| Montpellier Investments Limited | Construction | 1999 |
| Montpellier Land & Development Consultancy Ltd | Construction | 2009 |
| Montpellier Legal Ltd | Professional & scientific | 2021 |
| Montpellier Management Limited | Real estate | 2015 |
| Montpellier Massage & Beauty Limited | Other services | 2023 |
| Montpellier Motorcars Limited | Wholesale & retail | 2020 |
| Montpellier Parade (Services) Limited | Households | 1975 |
| Montpellier Properties ER Ltd | Real estate | 2026 |
| Montpellier Property Management Limited | Real estate | 2024 |
| Montpellier Public Relations Limited | Professional & scientific | 2010 |
| Montpellier Residential Management Company Limited | Real estate | 2025 |
| Montpellier Trading Limited | Wholesale & retail | 2015 |
| Montpellier Ventures Limited | Administrative & support | 2022 |
| Monty and Buddy Limited | Professional & scientific | 2016 |
| Monty's Guitars Limited | Other services | 2013 |
| Mooba SF Limited | Hospitality | 2024 |
| Moolicious Ltd | Wholesale & retail | 2023 |
| Moon Rascals Ltd | Wholesale & retail | 2022 |
| Moon Under Water (Holdings) Limited | Manufacturing | 2018 |
| Moonglow Trading Limited | Extraterritorial | 2022 |
| Moonmouse Creative Limited | Administrative & support | 2005 |
| Moorcounty Limited | Real estate | 1971 |
| Moore & LEE Estates Limited | Real estate | 2020 |
| Moorend Woodland Limited | Agriculture & fishing | 1997 |
| Moorland Green Properties Limited | Construction | 2013 |
| Moorside Stars Nursery Ltd | Education | 2018 |
| Moosh at the MX Ltd | Hospitality | 2024 |
| Moosh at the Site (Cheltenham) Ltd | Hospitality | 2023 |
| Moosh Cheltenham Ltd | Hospitality | 2022 |
| Moov Chiropractic Ltd | Health & social care | 2026 |
| Moraira Systems Ltd | Information & communication | 2015 |
| Moran’S Eating House Ltd | Hospitality | 2017 |
| Morcote and ST Martins Property Limited | Households | 2012 |
| Mordros Limited | Administrative & support | 2021 |
| More Mora Ltd | Administrative & support | 2023 |
| More OR Less Creative Limited | Information & communication | 2013 |
| Moreton Kitchen Limited | Hospitality | 2022 |
| Moretti & Rosini Ltd | Wholesale & retail | 2004 |
| Morgan Associates (Cheltenham) Limited | Real estate | 1965 |
| Morgan Associates (Cheltenham) Sales Limited | Real estate | 2020 |
| Morgan Elliot Planning Limited | Construction | 2022 |
| Morgan's Services Limited | Other services | 2022 |
| Morgenstond Group Limited | Professional & scientific | 2025 |
| Morky Mc'Morkisons Ltd | Construction | 2023 |
| Morland Roberts Limited | Administrative & support | 2022 |
| Morpheus Medical Limited | Health & social care | 2012 |
| Morphos Global Limited | Professional & scientific | 2025 |
| Morran Property Group Ltd | Financial services | 2024 |
| Morroway Developments Ltd | Extraterritorial | 2024 |
| Morroway Ltd | Financial services | 2024 |
| Mortgage Advice Centre (South West) Ltd | Financial services | 2001 |
| Mortimer Nominees Limited | Real estate | 2001 |
| Mortonville Residents Company Limited | Households | 1988 |
| MOS Produce Ltd | Wholesale & retail | 2025 |
| Mosaic Search & Selection Limited | Administrative & support | 2000 |
| Moss Construction and Project Management Limited | Construction | 2017 |
| Moss Green Holdings Ltd | Wholesale & retail | 1998 |
| Moss House Interiors LLP | | 2025 |
| Mossi Properties Investment Ltd | Real estate | 2021 |