| Mystic Reels Ltd | Information & communication | 2024 |
| Mystra Consulting Ltd | Professional & scientific | 2025 |
| Mythosplus Ltd | Hospitality | 2025 |
| MZB Ecom Hub Ltd | Wholesale & retail | 2025 |
| MZC Ltd. | Health & social care | 2011 |
| Mziu Properties Ltd | Real estate | 2022 |
| Mziu Rooms Ltd | Hospitality | 2022 |
| Mziu Shisha Lounge Ltd | Hospitality | 2022 |
| MZL Bellator Ltd | Construction | 2024 |
| N & K Cleaning Services 25 Limited | Administrative & support | 2025 |
| N & K Cleaning Services Limited | Administrative & support | 2025 |
| N & P Engineering Services Ltd | Professional & scientific | 2007 |
| N a Raven Limited | Manufacturing | 2014 |
| N Bishop & Co Ltd | Real estate | 2018 |
| N Brown Plumbing & Heating Ltd. | Construction | 2001 |
| N C Architects Limited | Professional & scientific | 2002 |
| N Cole Plastering & DRY Lining Limited | Professional & scientific | 2019 |
| N D Technology Holdings Limited | Financial services | 2015 |
| N H Composites Ltd | Administrative & support | 2010 |
| N J Johnston Ltd | Professional & scientific | 1996 |
| N M Ahmed Investments Ltd | Real estate | 2019 |
| N MAC Holdings UK Limited | Financial services | 2026 |
| N P D Electrical Limited | Professional & scientific | 2019 |
| N Plus a Ltd | Education | 2020 |
| N S L Barbers Ltd | Other services | 2025 |
| N T Sawyer Limited | Professional & scientific | 2022 |
| N&D Sweet Dreams Ltd | Wholesale & retail | 2022 |
| N&D Sweet Village Ltd | Wholesale & retail | 2024 |
| N&H Dataai Service Limited | Wholesale & retail | 2026 |
| N&M Property Management Ltd | Real estate | 2022 |
| N&S Rental Holding Ltd | Real estate | 2022 |
| N. P Enwezor Pharma Services Limited | Wholesale & retail | 2022 |
| N. Perry QS Limited | Professional & scientific | 2004 |
| N.C. Opportunist Ltd | Information & communication | 2005 |
| N.D.Technology Limited | Manufacturing | 2004 |
| N.L. FOX Property Ltd | Real estate | 2023 |
| N.Rys House Renovations Ltd | Construction | 2023 |
| N.T.A Roofing and Cladding Ltd | Construction | 2026 |
| N3 Air B and B Ltd | Real estate | 2025 |
| NA Law Limited | Professional & scientific | 2017 |
| NA Lettings Ltd | Real estate | 2022 |
| NA Planning Ltd | Professional & scientific | 2017 |
| Nabaco Limited | Hospitality | 2026 |
| Nable Supported Living Limited | Administrative & support | 2025 |
| Nabline Ltd | Construction | 2021 |
| Nago Enterprise Ltd | Health & social care | 2012 |
| Naiad Dynamics UK Limited | Manufacturing | 2008 |
| Nail Bar 1C Ltd | Other services | 2024 |
| Nails 2 Nails & Beauty Limited | Other services | 2022 |
| Nakama Enterprises Ltd | Hospitality | 2024 |
| Naked Food Innovations Limited | Other services | 2023 |
| Nala Jewellery Ltd | Wholesale & retail | 2025 |
| Nali Property Ltd | Real estate | 2023 |
| Nalu Homes SPV 101 Limited | Construction | 2017 |
| Nalu Limited | Construction | 2017 |
| NAM Tran Beauty Ltd | Other services | 2025 |
| Nandrews Limited | Wholesale & retail | 2001 |
| Nanotech Marine Services Ltd | Manufacturing | 2015 |
| Nansco Limited | Real estate | 2019 |
| NAO Lamon Limited | Health & social care | 2025 |
| Naomi Healthcare Ltd | Health & social care | 2023 |
| Naono Cleur Limited | Wholesale & retail | 2025 |
| NAP UK Enterprises Limited | Construction | 2019 |
| Napoli Taylor Developments Limited | Construction | 2025 |
| Nara Delight Ltd | Hospitality | 2020 |
| Nara Southampton Ltd | Hospitality | 2024 |
| Narcis Motors Ltd | Wholesale & retail | 2025 |
| Nardi Contractors Ltd | Construction | 2024 |
| Narmi Skin Ltd | Wholesale & retail | 2026 |
| Naronggame Limited | Information & communication | 2025 |
| Narti Clothing Limited | Wholesale & retail | 2020 |
| NAS Plant Limited | Administrative & support | 1997 |
| Nasaran Holdings Ltd | Wholesale & retail | 2024 |
| Nascenti Limited | Extraterritorial | 2021 |
| Nasiru Taura Ltd | Professional & scientific | 2024 |
| Nass South Ltd | Water & waste | 2023 |
| Nasz Sklep (Southampton) Limited | Wholesale & retail | 2016 |
| Natali Healthcare Solutions UK Ltd | Health & social care | 2024 |
| Natalie Page Aesthetics Academy Ltd | Education | 2022 |
| Natalie Page Aesthetics Limited | Other services | 2022 |
| Natalie Reynolds Limited | Professional & scientific | 2017 |
| Natalie Richmond Communications Limited | Professional & scientific | 2024 |
| Natant Blue Ltd | Professional & scientific | 2021 |
| Nathan's PAW Care Ltd | Other services | 2022 |
| Nathan's PAW Trails Ltd | Other services | 2022 |
| Nathan's PAW Training Ltd | Other services | 2020 |
| Nation Training Limited | Education | 2016 |
| National Boat Shows Limited | Administrative & support | 1955 |
| National Home Surveys Ltd | Construction | 2025 |
| National Independent Health Care Services Ltd | Real estate | 2022 |
| National Oceanography Centre | Professional & scientific | 2018 |
| National Oceanography Centre Innovations Limited | Professional & scientific | 2019 |
| Nations Farm Limited | Real estate | 1987 |
| Nationwide Concreting Limited | Construction | 2010 |
| Nationwide Contract Cleaners Limited | Professional & scientific | 1971 |
| Nationwide Elisei Couriers Ltd | Transport & logistics | 2022 |
| Nationwide Plant & Property Limited | Real estate | 2015 |
| Nationwide Pressure Washers Limited | Manufacturing | 2021 |
| Nationwide Renovation & Maintenance Ltd | Construction | 2024 |
| Native School of Music Ltd | Education | 2020 |