| Norwich Dental Ltd | Health & social care | 2021 |
| Norwood Systems Limited | Extraterritorial | 2011 |
| Nostara Limited | Arts & recreation | 2017 |
| Nostro Cafe Ltd | Wholesale & retail | 2023 |
| NOT Just an Accountant Limited | Professional & scientific | 2007 |
| NOT Just Tickets Ltd | Information & communication | 2020 |
| Nota Bene Health Ltd | Health & social care | 2013 |
| Notary Services Limited | Professional & scientific | 2022 |
| Noteaide Ltd | Extraterritorial | 2025 |
| Nothing BUT Epic Limited | Information & communication | 2017 |
| Notion Labs United Kingdom, Private Limited | Information & communication | 2022 |
| Notorem Ltd | Information & communication | 2026 |
| Notus Consulting Limited | Professional & scientific | 2020 |
| Nouveau HD Beauty Group Limited | Other services | 2019 |
| Nouveau Tile Limited | Construction | 2022 |
| Nova Domus Limited | Administrative & support | 2009 |
| Nova Efficax Limited | Administrative & support | 2025 |
| Nova Group Limited | Manufacturing | 1980 |
| Nova MCR Ltd | Wholesale & retail | 2025 |
| Nova Measurements (UK) Limited | Professional & scientific | 2022 |
| Nova Metrix (UK) Limited | Professional & scientific | 2014 |
| Nova Risk Limited | Professional & scientific | 2024 |
| Nova Software Limited | Information & communication | 2013 |
| Novakem Limited | Wholesale & retail | 2011 |
| Novapane Insulating Glass Limited | Manufacturing | 1975 |
| Novaterra Energy (UK) Limited | Professional & scientific | 2026 |
| Novaturient Holdings Ltd | Health & social care | 2022 |
| Novax International Ltd | Administrative & support | 2024 |
| Novax Recruitment Ltd | Administrative & support | 2020 |
| Noveau Consulting Services Limited | Administrative & support | 2009 |
| Novelly Limited | Wholesale & retail | 2019 |
| Novo Living Ltd | Real estate | 2025 |
| Novo Portfolio Services Limited | Real estate | 2022 |
| Novo Property Group Limited | Professional & scientific | 2003 |
| Novomedics Limited | Health & social care | 2015 |
| Novus Analytics Ltd | Administrative & support | 2022 |
| NOW Boarding Limited | Professional & scientific | 2019 |
| NOW Financial Planning Limited | Financial services | 2022 |
| Nowgene Limited | Wholesale & retail | 2016 |
| NP Lettings and Deal Sourcing Limited | Real estate | 2020 |
| NPS Client Services Ltd | Health & social care | 2023 |
| NRF Projects Limited | Professional & scientific | 2024 |
| NRM Consulting Limited | Professional & scientific | 2025 |
| Nrsa Group Limited | Financial services | 2025 |
| NS Engineering Services Limited | Administrative & support | 2015 |
| Ns&Co Limited | Real estate | 2024 |
| NSA Property Holdings LLP | | 2021 |
| Nsayeed Limited | Health & social care | 2017 |
| NT Therapy Ltd | Health & social care | 2024 |
| NTE Optical Limited | Financial services | 2024 |
| Nucifora Cardiac Imaging Ltd | Real estate | 2022 |
| Nucigent Technology Private Limited | Information & communication | 2019 |
| Nucleus Business Solutions Limited | Professional & scientific | 2004 |
| Nucleus Engineering Solutions Limited | Professional & scientific | 2020 |
| Nudge Limited | Professional & scientific | 2019 |
| NUE Staffing Solutions Limited | Professional & scientific | 2018 |
| Nuffle Labs UK Limited | Professional & scientific | 2024 |
| Nula Holdings Limited | Financial services | 2026 |
| Nullarbor Limited | Health & social care | 2011 |
| Number 7 Commercial and Procurement Services Limited | Administrative & support | 2023 |
| Numero UNO Group UK Ltd | Administrative & support | 2024 |
| Nunhead Housing Management Limited | Real estate | 2014 |
| Nursling Industrial Estate Ltd | Financial services | 2026 |
| Nursling Industrial Units 1-5 42 42A 45 Ltd | Financial services | 2026 |
| Nursling Industrial Units 8A-10 17 18 Ltd | Financial services | 2026 |
| Nurture Psychology Ltd | Health & social care | 2015 |
| Nurtured Roots Psychology Ltd | Health & social care | 2019 |
| Nurturo Training Limited | Education | 2026 |
| Nusantara Consultancy Limited | Professional & scientific | 2025 |
| Nuta Health Ltd | Health & social care | 2022 |
| Nuta Properties Ltd | Real estate | 2025 |
| Nuta Systems Ltd | Information & communication | 2025 |
| Nutricoach Limited | Hospitality | 2023 |
| Nutrimed Pharma Ltd | Health & social care | 2023 |
| Nuvation BIO UK Limited | Professional & scientific | 2022 |
| NVP Consulting Limited | Administrative & support | 2015 |
| NW Business Consultants Limited | Professional & scientific | 2008 |
| NW Marketing Suite Limited | Professional & scientific | 2023 |
| NW Surgical Solutions LLP | | 2013 |
| NWF Advisory Ltd | Financial services | 2026 |
| NWI Cavell 1 Limited | Real estate | 2020 |
| NWI Cavell 2 Limited | Real estate | 2020 |
| NWI Cheshire Limited | Administrative & support | 2007 |
| NWI Edgbaston J1 Limited | Real estate | 2019 |
| NWI Edgbaston J2 Limited | Real estate | 2019 |
| NWI Huddersfield 1 Limited | Real estate | 2020 |
| NWI Huddersfield 2 Limited | Real estate | 2020 |
| NWI Lancaster 1 Limited | Real estate | 2020 |
| NWI Lancaster 2 Limited | Real estate | 2020 |
| NWI Lincoln 1 Limited | Real estate | 2020 |
| NWI Lincoln 2 Limited | Real estate | 2020 |
| NWI ST Edmunds 1 Limited | Real estate | 2020 |
| NWI ST Edmunds 2 Limited | Real estate | 2020 |
| NWP Land Limited | Real estate | 2022 |
| NX Projects Ltd | Information & communication | 2026 |
| NZA Legal Ltd | Professional & scientific | 2026 |
| O & M SUB Limited | Hospitality | 2015 |
| O DEW Consulting Limited | Professional & scientific | 2014 |
| O'Donnell Duckworth Ltd | Professional & scientific | 2019 |
| O'Hara Construction Limited | Construction | 2011 |