| Nextech Ltd. | Manufacturing | 2011 |
| Nextgen Tutoring Limited | Education | 2024 |
| Nextleap Careers Limited | Professional & scientific | 2025 |
| Nextstep Technologies Ltd | Information & communication | 2024 |
| Nexus Engineering Partners Ltd | Professional & scientific | 2023 |
| Nexus Multimedia Group Limited | Information & communication | 2026 |
| Nexus Networking - Colchester - Dinner Limited | Other services | 2023 |
| Nexus Networking Limited | Information & communication | 2013 |
| Nexus Point Advisors Ltd | Professional & scientific | 2026 |
| Nexus Properties Partners Ltd | Real estate | 2024 |
| Nexus Technology & Media Limited | Wholesale & retail | 2004 |
| Nexus Technology Limited | Information & communication | 2023 |
| Nexuss Solutions Ltd. | Health & social care | 2020 |
| Nexxys Limited | Professional & scientific | 2003 |
| NF Fowler Ltd | Financial services | 2025 |
| Ngage HR Consultants Limited | Administrative & support | 2023 |
| Ngai LUN Limited | Wholesale & retail | 2024 |
| NGL Properties Ltd | Real estate | 2017 |
| NGL Wealth Management Ltd | Professional & scientific | 2020 |
| NGL1 Limited | Wholesale & retail | 2022 |
| Ngozi 2 Limited | Health & social care | 2026 |
| NGS Pharma Ltd | Wholesale & retail | 2011 |
| Ngwroofing Ltd | Construction | 2026 |
| Nhnb Investments Limited | Administrative & support | 2017 |
| NHP Wealth Management Ltd | Professional & scientific | 2024 |
| Nice Enterprises Limited | Real estate | 2018 |
| Nicety Solutions and Services (UK) Ltd | Wholesale & retail | 2023 |
| Niche Coordination Ltd | Administrative & support | 2026 |
| Niche IT Consultants Ltd | Information & communication | 1987 |
| Nicholas Anthony (Ascot) LLP | | 2010 |
| Nicholas Anthony (Colchester) LLP | | 2010 |
| Nicholas Anthony (Contracts) LLP | | 2010 |
| Nicholas Anthony (Wigmore Street) LLP | | 2010 |
| Nicholas Anthony Group Limited | Professional & scientific | 1997 |
| Nicholas Anthony Services Limited | Wholesale & retail | 1992 |
| Nicholas Family & Partners Ltd | Information & communication | 2024 |
| Nicholas Graham Builders Ltd | Construction | 1999 |
| Nicholas Percival Limited | Real estate | 2012 |
| Nicholas R Eddings Ltd | Construction | 2023 |
| Nick C Morgan Ltd | Professional & scientific | 2026 |
| Nick Mayles Limited | Professional & scientific | 2010 |
| Nick Perry Associates Limited | Professional & scientific | 2016 |
| Nick Rose Coaching and Consultancy Limited | Professional & scientific | 2023 |
| Nico Automotive Ltd | Wholesale & retail | 2018 |
| Nicola Jane Limited | Wholesale & retail | 1983 |
| Nicola Watts Ltd | Other services | 2009 |
| Nicolau Transport Ltd | Transport & logistics | 2020 |
| Nicoll Farm Ltd | Construction | 2024 |
| NIF (UK) Limited | Wholesale & retail | 2000 |
| Nigerian Physiotherapists United Kingdom Limited | Other services | 2023 |
| Nightingale Court Colchester Estate Management Limited | Households | 2000 |
| Nightingale Joinery Limited | Construction | 2008 |
| Nightowls Home Care Limited | Health & social care | 2015 |
| Nihal Healthcare Ltd | Wholesale & retail | 2015 |
| Nikanna Ltd | Real estate | 2023 |
| Niki Osteopathy Ltd | Health & social care | 2013 |
| Nikko Property Ltd | Real estate | 2021 |
| Nilkanth Inc Ltd | Hospitality | 2025 |
| Nimmi Retail Limited | Hospitality | 2020 |
| Nimpy Ltd | Real estate | 2024 |
| Niner PUB Limited | Hospitality | 2025 |
| Niscar Ltd | Wholesale & retail | 2022 |
| Nisha Katona Limited | Professional & scientific | 2016 |
| Nitabiri Limited | Health & social care | 2024 |
| Nivorin Ltd | Financial services | 2020 |
| Nixr Ltd | Information & communication | 2024 |
| Nixson & Nixson Limited | Professional & scientific | 2015 |
| NJ Consulting Services Ltd | Professional & scientific | 2016 |
| NJB Shocks Limited | Wholesale & retail | 2000 |
| Njjb Investments Limited | Professional & scientific | 1998 |
| Njoya Studios Limited | Arts & recreation | 2021 |
| NJP Associates Ltd | Professional & scientific | 2025 |
| Nnesm Holdings Ltd | Financial services | 2018 |
| NO Hope Limited | Arts & recreation | 2017 |
| NO Name Bar & Games Ltd | Arts & recreation | 2023 |
| NO Name Bar Events Ltd | Hospitality | 2026 |
| NO. 68 Boutique Limited | Construction | 2026 |
| Noaa Ltd | Professional & scientific | 2019 |
| Noahs Oak Limited | Construction | 2015 |
| Nobelday Flat Management Company Limited | Households | 1981 |
| Nobledigital Limited | Professional & scientific | 2023 |
| Noblepath Care Ltd | Health & social care | 2025 |
| Noctis Ltd | Transport & logistics | 2019 |
| Nocturna Limited | Professional & scientific | 2025 |
| Noggins Homes Ltd | Hospitality | 2024 |
| Nolton Place Management Limited | Households | 1997 |
| Nolvera Ltd | Professional & scientific | 2024 |
| Nomadita Ltd | Hospitality | 2026 |
| Nominal SUM Limited | Administrative & support | 2012 |
| NON Stop NON Stop Ltd | Wholesale & retail | 2025 |
| Non-Core Bidco 1 Limited | Health & social care | 2013 |
| Non-Core Bidco 2 Limited | Health & social care | 2013 |
| Non-Core Bidco 3 Limited | Extraterritorial | 2013 |
| Noonmar Limited | Administrative & support | 2020 |
| Noori Grill Bros Ltd | Hospitality | 2025 |
| Noori Pizza Bros Ltd | Hospitality | 2025 |
| Norbury Close 1970 Limited | Extraterritorial | 2014 |
| Nord Bathrooms and Saunas Limited | Wholesale & retail | 2026 |
| Nordic Experience Limited | Administrative & support | 2014 |
| Norfolk Autistic Society | Health & social care | 2001 |