| Moulding Bespoke Concepts Limited | Wholesale & retail | 2025 |
| Moulin Roty (UK) Limited | Wholesale & retail | 2002 |
| Mount Odessa Services Ltd | Administrative & support | 2026 |
| Mountcastle Properties Ltd | Real estate | 2019 |
| Mounted Prints Limited | Wholesale & retail | 2025 |
| Mountguard Properties Limited | Real estate | 1995 |
| Moviemedico Ltd | Professional & scientific | 2020 |
| Moyogi Limited | Information & communication | 2010 |
| Moztech Security Limited | Information & communication | 2019 |
| Mozzi Bikes Ltd | Wholesale & retail | 2013 |
| MP Telecoms Limited | Information & communication | 2023 |
| Mpayton Solutions Ltd | Information & communication | 2019 |
| MPC Services Limited | Professional & scientific | 2007 |
| MPC Systems (North) Limited | Construction | 2012 |
| MPC Systems Holdings Limited | Financial services | 2025 |
| MPD (Derbyshire) Limited | Professional & scientific | 2021 |
| MPG Packaging Limited | Administrative & support | 2014 |
| Mpom Limited | Professional & scientific | 2024 |
| MR and MRS Mortgage Broker Ltd | Financial services | 2024 |
| MR Emergency Medical Services Ltd | Health & social care | 2016 |
| MR Resin Limited | Manufacturing | 2018 |
| MR. Heywood's Carpets Limited | Wholesale & retail | 1983 |
| MRG Mortgages and Protection Ltd | Financial services | 2025 |
| MRS Green's Eco Store Ltd | Wholesale & retail | 2021 |
| Mrsbsi Limited | Wholesale & retail | 2016 |
| MS ARB Access Ltd | Construction | 2024 |
| MS Motors Ltd | Administrative & support | 2023 |
| MS Sekhon Transport Ltd | Transport & logistics | 2025 |
| Msda Properties Ltd | Real estate | 2020 |
| MSK Ingredients & Equipment Limited | Financial services | 2015 |
| MSK Ingredients Limited | Hospitality | 2005 |
| MSK Local Ltd | Wholesale & retail | 2023 |
| MSL Pumps Limited | Manufacturing | 2007 |
| MSM Property Rentals Ltd | Real estate | 2009 |
| Msssales Ltd | Wholesale & retail | 2026 |
| Mssvehicles Ltd | Wholesale & retail | 2026 |
| MTB Automotive Ltd | Wholesale & retail | 2022 |
| MTF Property Limited | Real estate | 2026 |
| MTG Civils Ltd | Construction | 2026 |
| MTI Building Services Ltd | Construction | 2019 |
| MTM Competency Ltd | Mining & quarrying | 2014 |
| MTR People Development Ltd | Professional & scientific | 2011 |
| MTS Transport Ltd | Wholesale & retail | 2002 |
| Muck Truck Grab Services Limited | Water & waste | 2008 |
| Muckyduckpubs Ltd | Hospitality | 2017 |
| Mughal KAS Limited | Hospitality | 2025 |
| Mulberry Walk Management Company Limited | Real estate | 2019 |
| Multiplex Engineering Holdings Limited | Financial services | 2024 |
| Multiplex Engineering Limited | Other services | 1989 |
| Munro Services Ltd | Professional & scientific | 2020 |
| Musa & Son's Ltd | Wholesale & retail | 2025 |
| Musicstyling.Com Limited | Manufacturing | 2004 |
| Mutley Construction Limited | Construction | 2021 |
| Mutley Investments Holdings Limited | Financial services | 2023 |
| Mutley Investments Limited | Professional & scientific | 2020 |
| Mutley Leisure Limited | Hospitality | 2021 |
| Mutley Property Portfolio Limited | Real estate | 2022 |
| Muzak (UK) Limited | Manufacturing | 1998 |
| MVI Transport Ltd | Transport & logistics | 2018 |
| MW Optical Limited | Health & social care | 2011 |
| MW Property Group Limited | Real estate | 2020 |
| MW Window Systems (Residential) Limited | Construction | 2026 |
| MW Window Systems Limited | Construction | 2017 |
| MXP Property Limited | Real estate | 2025 |
| Mxpc Development Ltd | Financial services | 2026 |
| My Bathroom Limited | Construction | 2013 |
| My House Calow Ltd | Health & social care | 2021 |
| My Little World (East Midlands) Ltd | Education | 2022 |
| My Moto FIX Ltd | Wholesale & retail | 2025 |
| My Sanctuary Ltd | Other services | 2022 |
| My World - Children's Role Play Centre Ltd | Hospitality | 2025 |
| My-Pad Manchester Ltd | Real estate | 2014 |
| Myaccountico Limited | Professional & scientific | 2024 |
| Mycare Homes Limited | Health & social care | 2001 |
| Myella Holdings Limited | Financial services | 2024 |
| Myhill Cycling Ltd | Manufacturing | 2023 |
| Myla Rose Holdings Ltd | Professional & scientific | 2021 |
| Myla Trades Limited | Wholesale & retail | 2022 |
| Mylae Trades Limited | Wholesale & retail | 2025 |
| Mynott & Wright Limited | Construction | 1972 |
| Mypumpkin Limited | Real estate | 2024 |
| Myronko Leisure Ltd | Agriculture & fishing | 2006 |
| MZ 19 Limited | Wholesale & retail | 2026 |
| N & D Property Holdings Ltd | Financial services | 2025 |
| N & D Property Investments Ltd | Real estate | 2023 |
| N & D Property Rental Ltd | Real estate | 2025 |
| N & V Distribution Ltd | Wholesale & retail | 2024 |
| N a Surveyors Limited | Professional & scientific | 2013 |
| N D King Limited | Wholesale & retail | 2007 |
| N Harland & Sons Limited | Transport & logistics | 2024 |
| N J Edwards Properties Limited | Real estate | 2023 |
| N J G C Developments Limited | Construction | 2018 |
| N S S Brimington Limited | Wholesale & retail | 2004 |
| N S Tomlinson Security Services Ltd | Administrative & support | 2019 |
| N T Killingley Ltd | Administrative & support | 2004 |
| N&H Care Limited | Health & social care | 2017 |
| N.T.N. Aerospares Limited | Administrative & support | 2003 |
| Nacom Automation Ltd | Manufacturing | 2002 |
| Nacom Holdings Ltd | Professional & scientific | 2022 |
| Nagbico 100 Limited | Health & social care | 2020 |