| Mica Yoga Ltd | Arts & recreation | 2024 |
| Michael B Wilkes CS Ltd | Professional & scientific | 2018 |
| Michael Farley & Associates Ltd | Professional & scientific | 2010 |
| Michael Grubb Studio Limited | Professional & scientific | 2012 |
| Michael Mcglynn Painting and Decorating Ltd | Construction | 2024 |
| Michael Reid Ltd | Construction | 2000 |
| Michael Rose Organisation Limited | Arts & recreation | 2017 |
| Michael Rose Trading Ltd | Wholesale & retail | 2015 |
| Michael Simpson Photography Ltd | Professional & scientific | 2018 |
| Michael Wilson Limited | Health & social care | 2015 |
| Michaels Limited | Health & social care | 1996 |
| Michal Cash and Point Ltd | Transport & logistics | 2020 |
| Michelle DA Costa Ltd | Health & social care | 2026 |
| Micro NAV Limited | Information & communication | 1995 |
| MICRO90 Limited | Information & communication | 2007 |
| Midas AFI Limited | Wholesale & retail | 2019 |
| Midas Estates Ltd | Real estate | 2001 |
| Midas Lettings and Property Management Ltd | Real estate | 2026 |
| Middleman Entertainment Ltd | Arts & recreation | 2013 |
| Middleton Outsourcing Ltd | Administrative & support | 2023 |
| Middleton Park Management (Bournemouth) Limited | Households | 1973 |
| Mifone Limited | Wholesale & retail | 2025 |
| Mighty Writer Limited | Education | 2015 |
| Mihai Trans Services Limited | Transport & logistics | 2014 |
| Mikah-Luna Ltd | Real estate | 2021 |
| Mike Fudge Plumbing and Heating Limited | Construction | 2014 |
| Mike Newman JNR Ltd | Arts & recreation | 2012 |
| Mike Newman Property Services Limited | Construction | 2013 |
| Mike Preen Limited | Wholesale & retail | 2023 |
| Mike Toon Limited | Water & waste | 2009 |
| Milborne Management Limited | Hospitality | 2026 |
| Milemarc Limited | Arts & recreation | 2014 |
| Miles Taxi 1 Limited | Transport & logistics | 2024 |
| Miles Taxi Limited | Transport & logistics | 2024 |
| Milford Property Ltd | Real estate | 2018 |
| Milhams Ltd | Administrative & support | 1995 |
| Militarua Ltd | Professional & scientific | 2017 |
| Mill Court (Wiveliscombe) Limited | Households | 2022 |
| Millar Maslin Associates Limited | Information & communication | 2011 |
| Millbank Residents Association Limited | Households | 1986 |
| Milldown Mews Ltd | Real estate | 2025 |
| Millennia Estates Services Limited | Real estate | 2021 |
| Millhams Street Management Limited | Households | 2000 |
| Millhurst Homes 2001 Limited | Construction | 2026 |
| Millifruit Ltd | Information & communication | 2025 |
| Milligan Home Care Ltd | Health & social care | 2022 |
| Millionaires Property Ventures Ltd | Real estate | 2026 |
| Millo Lodge Management Company Limited | Households | 1992 |
| Millpond Accountancy Services Limited | Professional & scientific | 2009 |
| Mills (BET) NO 1 Company Ltd | Extraterritorial | 2019 |
| Mills (BET) NO 2 Company Ltd | Extraterritorial | 2019 |
| Mills (Chattels) NO 1 Company Ltd | Extraterritorial | 2019 |
| Mills (Chattels) NO 2 Company Ltd | Extraterritorial | 2019 |
| Mills (Will) NO 1 Company Ltd | Extraterritorial | 2019 |
| Mills (Will) NO 2 Company Ltd | Extraterritorial | 2019 |
| Mills (Winkton) NO 1 Company Ltd | Extraterritorial | 2019 |
| Mills (Winkton) NO 2 Company Ltd | Extraterritorial | 2019 |
| Mills Chase Limited | Administrative & support | 2017 |
| Millsam Developments Limited | Construction | 1997 |
| Millstream House Management Company Limited | Households | 1997 |
| Milton Court Management Company (Ferndown) Limited | Households | 1975 |
| Milton Court RTM Limited | Households | 2003 |
| Milton E.J. Developments Limited | Real estate | 2023 |
| Milton House Freehold Limited | Real estate | 2008 |
| Milton Menswear Limited | Wholesale & retail | 2023 |
| Milton Pines Freehold Limited | Households | 2016 |
| Milton Villas Limited | Households | 2003 |
| Mimic Limited | Information & communication | 2012 |
| Mimis Food Limited | Manufacturing | 2016 |
| Mimosa Health and Beauty Limited | Health & social care | 2017 |
| Minaa Modest Fashion Limited | Wholesale & retail | 2024 |
| Minchin Meadow Limited | Administrative & support | 2026 |
| Mind OUT Arts CIC | Arts & recreation | 2023 |
| Mind OUT Theatre Ltd | Arts & recreation | 2023 |
| Mindcanyon Ltd. | Health & social care | 2018 |
| Mindex Data Services Limited | Information & communication | 1995 |
| Mindful Solutions Ltd | Other services | 2019 |
| Minerva Creative Consulting Limited | Professional & scientific | 2023 |
| Minfield Limited | Real estate | 2024 |
| Mini Manor Ltd | Hospitality | 2021 |
| Mini Monsters Cafe Ltd | Hospitality | 2021 |
| Mini Naples Pizza Limited | Hospitality | 2024 |
| Mini Naples Pizza Southbourne Ltd | Hospitality | 2025 |
| Mini Rome Cafe Limited | Hospitality | 2024 |
| Minibems Limited | Information & communication | 2016 |
| Minster Electrical Contractors Limited | Administrative & support | 2005 |
| Minster Mews Freehold Limited | Households | 2005 |
| Minster Wealth Management Limited | Extraterritorial | 2018 |
| Minsterview Estates Ltd | Real estate | 2006 |
| Minstrel Lodge Residents Association Limited | Households | 1991 |
| Mint Barbers - Bournemouth Ltd | Other services | 2019 |
| Mint Barbers - Westbourne Ltd | Other services | 2019 |
| Mint Hair Stylists Ltd | Other services | 2013 |
| Mintgb Limited | Wholesale & retail | 2023 |
| Minton Mews Management Company Limited | Households | 1987 |
| Minu Group Ltd | Hospitality | 2024 |
| MIR Taxi Limited | Transport & logistics | 2024 |
| Miracle Construction Ltd | Construction | 2021 |
| Mirage Hair and Beauty (Kinson) Limited | Other services | 2009 |
| Miranda Estates Ltd | Real estate | 2024 |