| Mudge&Co Ltd | Construction | 2025 |
| Mudge&Co. (FP) Ltd | Real estate | 2026 |
| Mulberry Tree Services Winchester Limited | Agriculture & fishing | 2013 |
| Multi-Turn Ltd | Manufacturing | 2012 |
| Munch at Unit 12 Community Interest Company | Hospitality | 2021 |
| Munch Community CIC | Hospitality | 2022 |
| Munday Enterprises Limited | Manufacturing | 2014 |
| Murphx Ltd | Information & communication | 2024 |
| Murray & Whittaker Limited | Real estate | 1933 |
| Murray Road Residents Association Limited | Households | 1981 |
| Muze Limited | Professional & scientific | 2012 |
| Muzo Health Ltd | Wholesale & retail | 2023 |
| My Digital Tax Advisers and Accountants Ltd | Professional & scientific | 2024 |
| My Memoir Limited | Wholesale & retail | 2022 |
| My Spare Seat Ltd | Other services | 2026 |
| Myalchemy.Ai Limited | Other services | 2023 |
| Myeco Limited | Professional & scientific | 2013 |
| Mylo Jones Limited | Wholesale & retail | 2014 |
| Myndful Mushrooms Ltd | Manufacturing | 2023 |
| Mythic Tabletop Games Limited | Wholesale & retail | 2025 |
| N a Saunders Limited | Professional & scientific | 2003 |
| N J Newman & Co Limited | Professional & scientific | 2004 |
| N Myburgh Ltd | Professional & scientific | 2019 |
| Nails 4 U Winchester Ltd | Other services | 2025 |
| Nairana Ltd | Professional & scientific | 2021 |
| Naisbitt Properties Limited | Real estate | 2025 |
| Namibian Hardwood UK Ltd | Wholesale & retail | 2022 |
| Nammara Properties Ltd | Real estate | 2025 |
| Nanfant Barns Limited | Households | 2021 |
| Nannie Health Care Services Ltd | Health & social care | 2014 |
| Naomi House Children's Hospice Ltd | Wholesale & retail | 1993 |
| Naomi Jane Restaurants Ltd | Hospitality | 2018 |
| Nascency Services Limited | Information & communication | 2016 |
| Nasus Pictures Ltd | Professional & scientific | 2021 |
| NAT Heys Limited | Administrative & support | 2021 |
| Natalie Allison Limited | Administrative & support | 2012 |
| National Heart of Worship CIC | Arts & recreation | 2021 |
| Native Snacks Ltd | Wholesale & retail | 2018 |
| Natural Health Garden Ltd | Manufacturing | 2023 |
| Naturally British Ltd | Wholesale & retail | 2018 |
| Naveed Medicare Ltd | Other services | 2012 |
| Naylors (Reading) Limited | Real estate | 1948 |
| NB Pottery Studio Limited | Manufacturing | 2025 |
| NDC Trading Ltd | Health & social care | 2014 |
| Nearby Tree Ltd | Construction | 2025 |
| Neat-House Interiors Limited | Manufacturing | 2016 |
| Needwant Limited | Manufacturing | 2009 |
| Neil O'Donnell Transport Management Limited | Professional & scientific | 2022 |
| Neil Robinson Consultancy Ltd | Information & communication | 2025 |
| Neil Smith Consulting Solutions Ltd | Information & communication | 2020 |
| Neil T101 Limited | Extraterritorial | 2004 |
| Neil T102 Limited | Extraterritorial | 1993 |
| Nemed Consulting Limited | Information & communication | 2016 |
| Nemed Property Services Limited | Real estate | 2017 |
| Nemisha Patel Owen Ltd | Other services | 2019 |
| Neon Moose Aviation Limited | Manufacturing | 2024 |
| Neon Moose Limited | Manufacturing | 2023 |
| Neon Profits Ltd | Real estate | 2026 |
| Neriah Drape & Decoris Ltd | Wholesale & retail | 2026 |
| Neston Cottles Ltd. | Wholesale & retail | 2005 |
| Nethaus Limited | Information & communication | 2000 |
| Netherwood Close Management Limited | Households | 2014 |
| Network Development LAB Ltd | Information & communication | 2020 |
| Network Infrastructure Solutions Ltd | Information & communication | 2024 |
| New Barn Farm Crawley Management Company Ltd | Households | 2005 |
| New Barn Holdings Limited | Transport & logistics | 2015 |
| New Digital Assets Limited | Information & communication | 2023 |
| New Energy Fitness Ltd | Arts & recreation | 2012 |
| New Energy Yoga Ltd | Arts & recreation | 2016 |
| New ERA Investments Limited | Real estate | 1987 |
| New ERA Management Limited | Extraterritorial | 1984 |
| New Forest Mobility Services Limited | Wholesale & retail | 2008 |
| New Forest Open Air Theatre Limited | Arts & recreation | 2025 |
| New Forest Venison Ltd | Wholesale & retail | 2025 |
| New JOB Support Ltd | Professional & scientific | 2023 |
| New Leadership Limited | Professional & scientific | 1999 |
| New Leaf Property Management Limited | Real estate | 2016 |
| New Leaf Together CIC | Health & social care | 2025 |
| New Leafe Freehold Ltd | Financial services | 2026 |
| New Leafe Sports & Social Group Ltd | Hospitality | 2026 |
| New Milton Tyre Company Limited | Extraterritorial | 2007 |
| New Oxford Court Residents Association Limited | Households | 2020 |
| New Star Project & Property Management Limited | Professional & scientific | 2007 |
| Newbury Riding for the Disabled Limited | Arts & recreation | 2005 |
| Newick Consulting Limited | Professional & scientific | 2024 |
| Newlands Place Management Company Limited | Households | 2025 |
| Newlyns LLP | | 2008 |
| Newton Physio Ltd | Health & social care | 2025 |
| Nextgen Chip Design Limited | Professional & scientific | 2010 |
| Nextjen PM Services (UK) Limited | Information & communication | 2025 |
| Nextrend Haven Ltd | Wholesale & retail | 2023 |
| NFV Consulting Limited | Financial services | 2012 |
| NGG & More Limited | Wholesale & retail | 2021 |
| Niagara Energy Consultancy Ltd | Professional & scientific | 2023 |
| Nick Ross Investments Limited | Health & social care | 2018 |
| Nielsen Parry Limited | Professional & scientific | 2010 |
| Nigel Guilder Limited | Other services | 2006 |
| Nigel Paul Partners Ltd | Professional & scientific | 2013 |
| Nightingale Development and Investment Ltd | Real estate | 2014 |
| Nightingale Walk Management Limited | Households | 1997 |