| Mindfield Media Ltd | Information & communication | 2010 |
| Mines Security Ltd | Extraterritorial | 2026 |
| Mini Market Buxton Ltd | Wholesale & retail | 2026 |
| Minnie ME Limited | Education | 2009 |
| Minton House Management Company Limited | Extraterritorial | 2011 |
| Mitchells Pre-Schools Limited | Education | 2013 |
| MIX and Batch Ltd | Manufacturing | 2019 |
| MLR Lifts Limited | Construction | 2012 |
| MMG Global Ltd | Professional & scientific | 2025 |
| Mobius Motors Limited | Manufacturing | 2010 |
| Modern Working UK Limited | Real estate | 2024 |
| Modulus Card Solutions Limited | Wholesale & retail | 2003 |
| Molina Craft Furniture Ltd | Manufacturing | 2023 |
| Monks Retreat Ltd | Real estate | 2001 |
| Mono-Tec Innovations Ltd | Construction | 2026 |
| Montane Care Limited | Administrative & support | 2019 |
| Montane Finance Limited | Administrative & support | 2019 |
| Montane Group Holdings Ltd | Financial services | 2022 |
| Montane I S Ltd | Real estate | 2022 |
| Montgomery Chambers Ltd | Professional & scientific | 2015 |
| Montgomery Thermostats Limited | Manufacturing | 1979 |
| Moorcroft Mews Management Limited | Households | 2002 |
| Moore Care (Registered) Limited | Health & social care | 1999 |
| Moore Care Developments Limited | Real estate | 2003 |
| Moore Care Holdings Limited | Financial services | 2017 |
| Moore Care Limited | Health & social care | 1994 |
| Moore Care Trustees Limited | Professional & scientific | 2018 |
| Moorside Homes Limited | Construction | 2011 |
| Morfose Barber Buxton Ltd | Other services | 2023 |
| Morgan J Sanders Associates Limited | Professional & scientific | 2025 |
| Morrell's Properties Limited | Real estate | 2016 |
| Movescape Ltd | Information & communication | 2015 |
| MPH Events Limited | Administrative & support | 2024 |
| MS & HM Eckert Ltd | Transport & logistics | 2004 |
| MST Sounds Ltd | Manufacturing | 2014 |
| Mullins Associates (Group) Limited | Professional & scientific | 2017 |
| Multimech Solutions Ltd | Professional & scientific | 2010 |
| Multisys Computers Limited | Information & communication | 1991 |
| Murray Jones Renovations Ltd | Real estate | 2021 |
| Mycock and Daughters Ltd | Health & social care | 2022 |
| Mycocks Agri Ltd | Agriculture & fishing | 2014 |
| Mycocks Properties Ltd | Real estate | 2025 |
| Mynoodle Bar Ltd | Hospitality | 2024 |
| Mysterious Times Ltd | Arts & recreation | 2024 |
| N Parker Electrical Limited | Manufacturing | 2013 |
| N Shipley Engineering Services Limited | Administrative & support | 2015 |
| N33EDO Ltd | Transport & logistics | 2016 |
| Naarnia Ltd | Wholesale & retail | 2025 |
| National Quarries Industrial Services Limited | Administrative & support | 2018 |
| Nationwide FM Limited | Administrative & support | 2023 |
| NB Site Solutions Ltd | Construction | 2024 |
| NCH DIGITAL90 Limited | Information & communication | 2025 |
| NDA Auto Services Limited | Manufacturing | 2010 |
| Ndbm Consulting Ltd | Administrative & support | 2024 |
| Nems (S.E.) Limited | Administrative & support | 2013 |
| Nested Support Ltd | Health & social care | 2019 |
| Neuro-Forensic Professionals Limited | Health & social care | 2019 |
| New Close Farm Catering Limited | Hospitality | 2014 |
| New Mills Dairies Ltd | Wholesale & retail | 2017 |
| New Zealand in Depth Limited | Administrative & support | 2015 |
| Newstead House Management Limited | Real estate | 2020 |
| Nice Venues Ltd | Wholesale & retail | 2024 |
| Nikmon Limited | Households | 2025 |
| Ninax Ltd | Real estate | 2008 |
| Nippleicious Ltd. | Manufacturing | 2015 |
| NJ Williams Commercials Ltd | Wholesale & retail | 2014 |
| NMG Legal (Costs) Ltd | Professional & scientific | 2026 |
| NO Hassle Group Limited | Construction | 2022 |
| Norburys Limited | Administrative & support | 2002 |
| Northern Value Creators Limited | Professional & scientific | 2016 |
| Northlight Consulting Limited | Professional & scientific | 2009 |
| Notspot Broadband Limited | Information & communication | 2011 |
| Novaquatics Ltd | Wholesale & retail | 1997 |
| Novo Projects Ltd | Financial services | 2024 |
| NP Aquatics Ltd | Agriculture & fishing | 2026 |
| NPS Glazing Systems Limited | Construction | 2002 |
| NRM Engineering Ltd | Professional & scientific | 2022 |
| Number One Buxton Limited | Real estate | 2024 |
| Numbers in Bloom Ltd | Professional & scientific | 2025 |
| Nunsfield Leisure Gardeners Limited | Arts & recreation | 2026 |
| Nusoft Limited | Manufacturing | 2019 |
| Nyxeltech Ltd | Information & communication | 2025 |
| NZ Kebab Ltd | Hospitality | 2026 |
| Oak Restoration Limited | Construction | 2001 |
| Obsidian Commercial Property Limited | Real estate | 2022 |
| Occupational Health Solutions Limited | Health & social care | 1998 |
| Odsal Motorsports Limited | Arts & recreation | 2021 |
| OFF the Market Investment Property Ltd | Real estate | 2019 |
| Off-Site Homes Alliance Limited | Construction | 2020 |
| Oilfield Sensing Ltd | Manufacturing | 2021 |
| OJD Properties Ltd | Real estate | 2017 |
| Oktangle Ltd | Professional & scientific | 2025 |
| Oligen Technologies Ltd | Manufacturing | 2017 |
| Oliver Henry Ltd | Construction | 2018 |
| Olly Watts Automotive Ltd | Wholesale & retail | 2022 |
| Omnico Ltd | Professional & scientific | 2004 |
| One Last Shot Ltd | Wholesale & retail | 2025 |
| One Stop Boogie Productions Limited | Arts & recreation | 2023 |
| Onicko Ltd | Information & communication | 2021 |
| Opafire Limited | Professional & scientific | 2014 |