| Midfield Limited | Agriculture & fishing | 1994 |
| Midland Trading Ltd | Wholesale & retail | 2019 |
| Midlands Premier Driveways Limited | Construction | 2022 |
| Midlands Premier Patios Limited | Construction | 2022 |
| Midlands Warehousing Limited | Transport & logistics | 2013 |
| Midnight Embers Ltd | Wholesale & retail | 2024 |
| Midwest Corporate Services (UK) Limited | Professional & scientific | 2025 |
| Mielczar Ltd | Transport & logistics | 2024 |
| Miftahul -ILM Academy CIC | Education | 2024 |
| Migatronic Welding Equipment Limited | Wholesale & retail | 1978 |
| Mighty Pizza Ltd | Hospitality | 2020 |
| Migora Consulting Limited | Information & communication | 2015 |
| Migrate Communications Ltd | Information & communication | 2018 |
| Mihai and K Logistic Ltd | Administrative & support | 2023 |
| Mihai Florea Limited | Transport & logistics | 2014 |
| Mike COX Consultancy Ltd | Professional & scientific | 2025 |
| Mike RIX Consulting Limited | Professional & scientific | 2010 |
| Mike Smart Security Ltd | Construction | 2019 |
| Mike's Famous Bookstall Limited | Wholesale & retail | 2024 |
| Mikez Ltd | Transport & logistics | 2025 |
| Mike’S Electrical Ltd | Construction | 2020 |
| Miki’S Bakery Limited | Hospitality | 2025 |
| Miko Services Ltd | Construction | 2025 |
| Mikoblech Ltd | Transport & logistics | 2023 |
| Mikou & Co. Limited | Extraterritorial | 2024 |
| Miku Developments Limited | Real estate | 2023 |
| MIL Lane Game Farm Ltd | Wholesale & retail | 2025 |
| Milan Materials Limited | Wholesale & retail | 2025 |
| Milan Rhodes Limited | Real estate | 2018 |
| Milano Food Ltd | Hospitality | 2000 |
| Mile END Farm Limited | Agriculture & fishing | 1998 |
| Mileage Trading Limited | Transport & logistics | 2015 |
| Milebond Limited | Real estate | 2013 |
| Miles Master Limited | Transport & logistics | 2022 |
| Miles Plant Services Limited | Manufacturing | 2020 |
| Milestone Ranch Country Park Limited | Wholesale & retail | 2024 |
| Milewood (Holdings) Ltd | Financial services | 2010 |
| Milewood Healthcare Ltd | Health & social care | 2002 |
| Milhug Holding Ltd | Financial services | 2023 |
| Military Training Limited | Extraterritorial | 2011 |
| Milkybk Ltd | Administrative & support | 2022 |
| Mill Capital Global Ltd | Professional & scientific | 2026 |
| Mill Court Consultants Limited | Professional & scientific | 2009 |
| Mill Garages North East Limited | Wholesale & retail | 2008 |
| Mill Stream View Ltd | Construction | 2020 |
| Mill Stream View Management Limited | Households | 2023 |
| Millbrook Homes (Doncaster) Limited | Real estate | 2004 |
| Milldons Ltd | Construction | 2023 |
| Miller Dutton Limited | Professional & scientific | 1996 |
| Millers Green (Sneinton) Management Company Limited | Households | 2002 |
| Millers Yard Construction Services Ltd | Real estate | 2009 |
| Millhouses Management Services Limited | Real estate | 2014 |
| Millhouses Property Services Limited | Real estate | 2019 |
| Millies Corner Ltd | Extraterritorial | 2012 |
| Milliseconds Limited | Information & communication | 2023 |
| Mills Medical Services Limited | Health & social care | 2012 |
| Millstone Ventures Limited | Real estate | 2025 |
| Miltex Limited | Wholesale & retail | 2003 |
| Milton Court (Blockley) Limited | Households | 2003 |
| Milvik Africa Holdings Limited | Financial services | 2021 |
| Mimarie Property Ltd | Real estate | 2025 |
| Mimet Ltd | Water & waste | 2015 |
| Mimi 91 Ltd | Transport & logistics | 2020 |
| Mimi Inc Ltd | Real estate | 2021 |
| Mimik Group Ltd | Hospitality | 2023 |
| Mimik Ltd | Transport & logistics | 2019 |
| Mimosa Holding Ltd | Financial services | 2024 |
| Mimzza Designs Ltd | Information & communication | 2020 |
| Mina Health Ltd | Health & social care | 2021 |
| Mina-Meva Limited | Professional & scientific | 2024 |
| Minbrooke Testing Services Ltd | Construction | 2015 |
| Mincom Ltd | Financial services | 2015 |
| Mind and ALL Limited | Health & social care | 2025 |
| Mind Legacy Ltd | Health & social care | 2026 |
| Mind Wellbeing Communities CIC | Education | 2025 |
| Mind Wellbeing Launchpad Limited | Professional & scientific | 2025 |
| Mindful Activities Yorkshire C.I.C. | Information & communication | 2020 |
| Mindful Gaming CIC | Wholesale & retail | 2024 |
| Mindling Design Limited | Professional & scientific | 2022 |
| Mindlounge Ltd. | Financial services | 2015 |
| Mindlyfter Ltd | Wholesale & retail | 2024 |
| Mindset Baits Limited | Manufacturing | 2025 |
| Mineral Processing Ltd | Mining & quarrying | 2012 |
| Miners Sports Group Limited | Arts & recreation | 2024 |
| Mini and Maxi Ltd | Wholesale & retail | 2024 |
| Mini Mezzz Childcare Limited | Health & social care | 2022 |
| Mini Moves Home Clearance Ltd | Transport & logistics | 2023 |
| Mini Shop Market Ltd | Wholesale & retail | 2025 |
| Minimae Limited | Wholesale & retail | 2025 |
| Minishop 1 Limited | Wholesale & retail | 2025 |
| Ministry of Herbs Limited | Health & social care | 2012 |
| Ministry Security Ltd | Administrative & support | 2025 |
| Mink Solutions Ltd | Administrative & support | 2014 |
| Mint Lantern Ltd | Extraterritorial | 2026 |
| Mint Meadow Group Ltd | Extraterritorial | 2026 |
| Mint People Services Ltd | Administrative & support | 2024 |
| MINT49 Ltd | Professional & scientific | 2026 |
| Miody Babci Anieli Ltd | Wholesale & retail | 2024 |
| Mira 27 Limited | Hospitality | 2025 |
| Miral Dominic Limited | Construction | 2006 |