| Mick Haywood Building Services Ltd | Construction | 2016 |
| Migar Homes Limited | Real estate | 2003 |
| Migar Investments Limited | Professional & scientific | 2015 |
| Mighty Imperial Ltd | Hospitality | 2024 |
| Mike Lambert Stunts Limited | Arts & recreation | 2012 |
| Millhouses Fencing & Sheds Limited | Construction | 2017 |
| Mini Pandas Ltd | Wholesale & retail | 2019 |
| Mint Homes (Leeds) Limited | Construction | 2024 |
| Minted INK Ltd | Arts & recreation | 2024 |
| Mirha Associates Ltd | Transport & logistics | 2023 |
| Mirha Logistics Ltd | Transport & logistics | 2026 |
| Mirha Retail Ltd | Wholesale & retail | 2026 |
| Mjof Properties Limited | Construction | 2024 |
| MKE Holdings Limited | Real estate | 2025 |
| MLB Autospares Limited | Wholesale & retail | 2012 |
| MLC Automotive Limited | Wholesale & retail | 2020 |
| Modaitaliana Ltd | Wholesale & retail | 2024 |
| Modaitaliano Ltd | Other services | 2023 |
| Monroes Takeaway Limited | Hospitality | 2021 |
| Montagu Chambers Limited | Real estate | 2023 |
| MOS Systems Ltd | Information & communication | 2012 |
| Motor City Services Ltd | Wholesale & retail | 2025 |
| MOVE2LET Ltd | Real estate | 2014 |
| MPC Management Limited | Professional & scientific | 2024 |
| MR O Domestic Electrical Installation Services Ltd | Construction | 2025 |
| MRG Autos Ltd | Wholesale & retail | 2019 |
| MRG Estates Ltd | Real estate | 2022 |
| MRR Transport Ltd | Administrative & support | 2016 |
| MS Prime Estates Ltd | Real estate | 2026 |
| MS Propco Limited | Water & waste | 2020 |
| MSC Rope Access Solutions Ltd | Construction | 2024 |
| MSP Construction Limited | Construction | 1998 |
| MSP Properties & Rentals Ltd | Real estate | 2012 |
| Mullfell Limited | Professional & scientific | 2024 |
| Muriishe Services Limited | Health & social care | 2020 |
| Musclefactory Gymnasium LLP | | 2025 |
| Muscroft Properties Limited | Real estate | 2025 |
| Mushda Ltd | Wholesale & retail | 2024 |
| Mustard’S @ the Station Ltd | Hospitality | 2025 |
| Mutachi Solutions Ltd | Information & communication | 2024 |
| MW Entertainments Limited | Extraterritorial | 2013 |
| MXB Trading Ltd | Wholesale & retail | 2023 |
| My Daddy Limited | Information & communication | 2018 |
| Mypizzahouse Ltd | Hospitality | 2024 |
| Mysticum Luna Ltd | Wholesale & retail | 2021 |
| N & S Contracting Limited | Administrative & support | 2011 |
| N B Properties (Yorkshire) Limited | Households | 2016 |
| N H Pipe Welding Services Limited | Manufacturing | 2005 |
| N. Fanthorpe & Company Limited | Construction | 2017 |
| N.P Matthewman Joinery & Developments Limited | Construction | 2025 |
| Nangyal Store Ltd | Wholesale & retail | 2026 |
| Nathern Limited | Real estate | 2025 |
| Navigate Accountancy Limited | Professional & scientific | 2004 |
| Navigate Waste Limited | Professional & scientific | 2025 |
| Nayak Solutions Ltd | Information & communication | 2026 |
| Ncube Optical Ltd | Health & social care | 2023 |
| Negative Capability Ltd | Information & communication | 2024 |
| Nestorra Group Ltd | Real estate | 2026 |
| Netheredge Properties Limited | Real estate | 2012 |
| New Design Trade Windows Limited | Construction | 2023 |
| New Design Windows Ltd | Manufacturing | 2019 |
| New Horizon Property Ltd | Construction | 2023 |
| New Horizon Realty Ltd | Construction | 2025 |
| New Vision Business Limited | Wholesale & retail | 2022 |
| New Wing Hing 132 Ltd | Hospitality | 2025 |
| Newton & Sharp Limited | Administrative & support | 2006 |
| Nexshop Ltd | Wholesale & retail | 2023 |
| Next Level Cleans Ltd | Administrative & support | 2025 |
| Nick Commercials Ltd | Transport & logistics | 2022 |
| Nicky Story Holdings Limited | Financial services | 2018 |
| Nigel Green Limited | Financial services | 2025 |
| Niids Ltd | Wholesale & retail | 2025 |
| NJH Mechanical Design Limited | Professional & scientific | 2015 |
| Njmm Brickwork Limited | Construction | 2024 |
| NL Property Services Limited | Real estate | 2020 |
| Nnsd Ltd | Hospitality | 2025 |
| NO.9 Thai Massage & Spa Ltd | Other services | 2022 |
| Noble E&I Services Ltd | Other services | 2017 |
| Nomad Property Services Ltd | Real estate | 2025 |
| Nomsy Pets Ltd | Manufacturing | 2026 |
| North Coast Construction (Northern) Limited | Construction | 2024 |
| Northdale Ltd | Construction | 2020 |
| Northern Health and Safety Practice Limited | Administrative & support | 2010 |
| Northern Installation Services Limited | Construction | 2000 |
| Northern Plant & Machinery (NE) Limited | Manufacturing | 2025 |
| Northern Property Sourcing Limited | Hospitality | 2023 |
| NS Health Care Ltd | Health & social care | 2015 |
| Nurtured Roots Limited | Agriculture & fishing | 2021 |
| Nutri-Dyn Ltd | Wholesale & retail | 2015 |
| Nutridyn Europe Limited | Wholesale & retail | 2013 |
| NYG Interim Limited | Professional & scientific | 2008 |
| Oakbury Consultants Limited | Information & communication | 2002 |
| Oilsales UK Ltd | Administrative & support | 2024 |
| Olimpia Homes Ltd | Financial services | 2025 |
| Oliver Properties (Barnsley) Limited | Real estate | 2023 |
| Oliver Wenthorpe Limited | Arts & recreation | 2018 |
| Oliwell Ltd | Real estate | 2023 |
| OLP Sports Bar Limited | Hospitality | 2018 |
| Omnicomply Group Ltd | Information & communication | 2026 |
| One Step Marketing Ltd | Professional & scientific | 2020 |