| Nilkanth Property Limited | Real estate | 2019 |
| Ninehex Limited | Real estate | 2025 |
| NINETEEN89 Holdings Limited | Financial services | 2023 |
| NINETYFOUR94 Limited | Wholesale & retail | 2025 |
| Ninsonia Holdings Limited | Financial services | 2026 |
| Ninsonia Property Limited | Real estate | 2026 |
| Nistreana Ltd | Construction | 2021 |
| NIT Property Ltd | Real estate | 2026 |
| Nitc Holdings Limited | Financial services | 2022 |
| Nith Services Limited | Other services | 2016 |
| Nithilam Consultancy Ltd | Information & communication | 2025 |
| Nitra Clean Ltd | Water & waste | 2021 |
| Nitro Tyres 24/7 Limited | Wholesale & retail | 2025 |
| Niyata Limited | Real estate | 2025 |
| NJH Consultancy Ltd | Professional & scientific | 2021 |
| NL Patel News Bouys Limited | Wholesale & retail | 2023 |
| NLY Building Services Ltd | Professional & scientific | 2016 |
| NME1 Care Limited | Health & social care | 2021 |
| Nnation Ltd | Construction | 2025 |
| NND Services Ltd | Transport & logistics | 2019 |
| Nnfm Ltd | Administrative & support | 2022 |
| NO Place Limited | Information & communication | 2020 |
| Noak Holdings Limited | Real estate | 2026 |
| Nobengo Limited | Other services | 2020 |
| Noble Aesthetics Ltd | Health & social care | 2018 |
| Noble East Anglia Limited | Health & social care | 2025 |
| Nobleton Limited | Hospitality | 2025 |
| Noesis Solutions Limited | Information & communication | 2022 |
| Nofa Limited | Real estate | 2024 |
| Nolan Brothers Property Management Limited | Real estate | 2018 |
| Nolan's Ltd. | Real estate | 1985 |
| Nolan's Properties Limited | Real estate | 1993 |
| Nolan's Properties Maintenance Limited | Administrative & support | 2001 |
| Nollyluxe Ltd | Wholesale & retail | 2026 |
| Nopi Care Ltd | Health & social care | 2013 |
| Noram Investments Ltd | Real estate | 2019 |
| Noramos Services Company Limited | Health & social care | 2013 |
| Norazen Ltd | Information & communication | 2024 |
| Norfolk Watersides Ltd | Agriculture & fishing | 2024 |
| Normar Contracts Ltd | Construction | 2025 |
| Norrington's Fire and Electrical Consultancy Limited | Construction | 2014 |
| Norris Consultants Limited | Professional & scientific | 2025 |
| North & Sterling Ltd | Wholesale & retail | 2026 |
| North INT. Ltd | Wholesale & retail | 2020 |
| North London Loft Rooms Limited | Construction | 2015 |
| North London Shutters Services Limited | Construction | 2024 |
| North Street Property Limited | Construction | 2014 |
| Northstar Homes Limited | Real estate | 2001 |
| Note Basildon Limited | Manufacturing | 2003 |
| Note Prototyping Limited | Manufacturing | 1997 |
| Noteloop Limited | Construction | 2022 |
| Notes Wine & Music Limited | Wholesale & retail | 2021 |
| Notsallow 134 Limited | Administrative & support | 2000 |
| Nova Dynamics Ltd | Information & communication | 2023 |
| Nova Fine Art Limited | Wholesale & retail | 2019 |
| Nova Invikta Limited | Transport & logistics | 2022 |
| Nova Music Group Limited | Arts & recreation | 2008 |
| Nova Presents Limited | Professional & scientific | 2019 |
| Novanet NS Ltd | Professional & scientific | 2023 |
| Novelty Arena Limited | Administrative & support | 2017 |
| Novilho Butcher Ltd | Wholesale & retail | 2020 |
| Novus Search Limited | Administrative & support | 2020 |
| Nowak Dental Laboratories Limited | Financial services | 2024 |
| NP Building Services Limited | Construction | 2014 |
| NPM Labs Ltd | Information & communication | 2026 |
| Nprm Ltd | Information & communication | 2025 |
| NR Ventures Ltd | Hospitality | 2023 |
| NS Homes Investments Ltd | Real estate | 2026 |
| NS3 Motors Ltd | Wholesale & retail | 2019 |
| Ntend Info Ltd | Information & communication | 2023 |
| Ntinga Holdings Limited | Manufacturing | 2024 |
| Ntinga Limited | Manufacturing | 2006 |
| Ntnl (Natural Teachers Natural Learners) Ltd | Wholesale & retail | 2021 |
| NU Eden Ltd | Wholesale & retail | 2019 |
| NU Energy Solar Limited | Construction | 2026 |
| NU Trading Lakeside Ltd | Hospitality | 2020 |
| NU Trading Romford Ltd | Hospitality | 2020 |
| Nu-Kleen Services Limited | Administrative & support | 1994 |
| Nugents Therapy Limited | Health & social care | 2025 |
| Nukan Publishing Ltd | Information & communication | 2024 |
| Nukleen Group Ltd | Administrative & support | 2013 |
| Nunya Business Limited | Extraterritorial | 2021 |
| NUR Barbers Ltd | Other services | 2026 |
| Nurdagi Ltd | Hospitality | 2021 |
| Nusprout Ltd | Manufacturing | 2025 |
| Nutland UK Limited | Wholesale & retail | 2017 |
| Nutra Healthcare Ltd | Wholesale & retail | 2021 |
| Nuttys Dive Centre Ltd | Wholesale & retail | 2025 |
| Nuventa Consulting Ltd | Professional & scientific | 2016 |
| NV Steelerecting Ltd | Construction | 2026 |
| NW Plumbing & Heating Services Ltd | Construction | 2023 |
| NW Properties London Ltd | Real estate | 2019 |
| NWM Vehicle & Marine Management Limited | Wholesale & retail | 2016 |
| NXT Retail Technologies Inc Ltd | Information & communication | 2021 |
| Nybites Limited | Health & social care | 2024 |
| Nyork OT Ltd | Health & social care | 2025 |
| Nziza Health Ltd | Health & social care | 2018 |
| O B C Management Limited | Real estate | 1988 |
| O M Persons New Ltd | Construction | 2024 |
| O&A Consulting Limited | Construction | 2025 |