| Noon Services Limited | Wholesale & retail | 2025 |
| Nordiccool Systems Ltd | Manufacturing | 2025 |
| North Abingdon Healthcare Ltd | Wholesale & retail | 2016 |
| North Hire and Sales Limited | Administrative & support | 2014 |
| North RD Leisure Ltd | Hospitality | 2020 |
| North West Building & Office Solutions Ltd | Construction | 2016 |
| North West Canine Hydrotherapy Limited | Administrative & support | 2020 |
| North West Car Exchange Ltd | Wholesale & retail | 2025 |
| North West Dog Grooming Ltd | Other services | 2024 |
| North West Learning Partnership Ltd | Education | 2015 |
| North West Medical Solutions Ltd | Education | 2017 |
| North West Medico Legal Services Ltd | Administrative & support | 2013 |
| North West Serviced Lets Limited | Real estate | 2017 |
| North West Shading Ltd | Administrative & support | 2019 |
| North West Vaping Supplies Limited | Wholesale & retail | 2015 |
| North West Vehicle Logistics Limited | Wholesale & retail | 2013 |
| Northeast Imaan Healthcare Ltd | Wholesale & retail | 2024 |
| Northern Industrial Services Ltd | Administrative & support | 2007 |
| Northern Monkey Investments Ltd | Wholesale & retail | 2021 |
| Northern Moor Healthcare Limited | Wholesale & retail | 2023 |
| Northern Star Coach Hire Ltd | Transport & logistics | 2024 |
| Northern Underground Trading Ltd | Hospitality | 2017 |
| Northern Ventures Group Ltd | Hospitality | 2017 |
| Northwest Installations Ltd | Construction | 2025 |
| Northwest Landscaping Ltd | Construction | 2024 |
| Northwest Moving Company Ltd | Transport & logistics | 2024 |
| Northwest Pet Grooming Ltd | Other services | 2025 |
| Northwest Skin and Laser Clinic Ltd | Other services | 2019 |
| Northwest Vehicles (NW) Ltd | Professional & scientific | 2026 |
| Norwood Healthcare Limited | Wholesale & retail | 2024 |
| Nova Health & Wellbeing Ltd | Health & social care | 2025 |
| Nova Pro Construction Ltd | Construction | 2026 |
| Novusnw CIC | Health & social care | 2025 |
| Nowosad Properties Ltd | Real estate | 2023 |
| NRA Property Investments Limited | Real estate | 2024 |
| NRS Interiors Ltd | Construction | 2021 |
| Nsdl (NW) Ltd | Transport & logistics | 2019 |
| Nssmt UK Ltd | Wholesale & retail | 2025 |
| NTD Shielding Services Ltd | Construction | 2009 |
| NTD Shielding Solutions Limited | Construction | 2015 |
| Ntmm & Co Limited | Transport & logistics | 2015 |
| Nunsthorpe Healthcare Limited | Wholesale & retail | 2026 |
| Nuri Properties Ltd | Real estate | 2026 |
| Nurture & Amity Services Ltd | Health & social care | 2026 |
| Nurture Support Services Limited | Health & social care | 2021 |
| Nutgrove Chapel Ltd | Other services | 2026 |
| Nutgrove Hall Management Company Limited | Households | 1996 |
| Nutrisol Limited | Wholesale & retail | 2021 |
| Nutwall Limited | Real estate | 2022 |
| Nuur Ltd | Wholesale & retail | 2009 |
| Nuwave Interpreting Limited | Professional & scientific | 2023 |
| Nuwave Investments Limited | Real estate | 2025 |
| NW Construction Limited | Financial services | 2026 |
| NWF Biomass Ltd | Transport & logistics | 2024 |
| Nwfm Limited | Construction | 2022 |
| Nx-Cam Limited | Manufacturing | 2006 |
| Nxtgen Quality Ltd | Education | 2017 |
| NYE Vigour Ltd | Wholesale & retail | 2024 |
| NYX Commercial Engineers Limited | Manufacturing | 2026 |
| NYX Facilities Ltd | Administrative & support | 2026 |
| O'Connor's Developments Ltd | Real estate | 2025 |
| O'Neills Property Development Ltd | Real estate | 2026 |
| Oak Road Healthcare Limited | Wholesale & retail | 2026 |
| Oaklands Literary Limited | Arts & recreation | 2016 |
| Oakley Independent Estate Planning Limited | Administrative & support | 2024 |
| Oakpharma Properties Ltd | Real estate | 2021 |
| Oasis Bin-Loc Limited | Manufacturing | 2010 |
| Oasislife Care Ltd | Health & social care | 2024 |
| Ocean Lettings Ltd | Real estate | 2023 |
| OG Rentals Ltd | Real estate | 2024 |
| OHS Fencing Ltd | Construction | 2026 |
| OJ Santos Holding Company Ltd | Financial services | 2025 |
| Ojas Limited | Professional & scientific | 2015 |
| Olayi Global Ltd | Manufacturing | 2024 |
| Old Hall PUB Co Ltd | Hospitality | 2019 |
| Olla Childrenswear Ltd | Wholesale & retail | 2025 |
| Olteanu Ltd | Transport & logistics | 2020 |
| Oluseyejade Medical Limited | Health & social care | 2025 |
| Omar Rehman Trendz Ltd | Wholesale & retail | 2025 |
| Omjo Ltd | Information & communication | 2026 |
| Omniforex Limited | Financial services | 2025 |
| ON Residentials Ltd | Real estate | 2026 |
| ON the Lash Limited | Other services | 2026 |
| One for the Road Ltd | Hospitality | 2019 |
| One Link Connect Ltd. | Administrative & support | 2022 |
| One SIX Eight Creatives Ltd | Information & communication | 2022 |
| One World One Climate Limited | Professional & scientific | 2023 |
| One-Off International Ltd | Wholesale & retail | 2026 |
| Onelonecoder Ltd | Arts & recreation | 2024 |
| Only Dessertz Ltd | Wholesale & retail | 2026 |
| Only Scrans Pizza Limited | Hospitality | 2026 |
| Onpoint Care Ltd | Health & social care | 2025 |
| Onpoint Group Ltd | Construction | 2018 |
| Onpoint Trac Hire Limited | Transport & logistics | 2022 |
| Onpoint Trac Ltd | Construction | 2018 |
| Ontime Care Services Ltd | Health & social care | 2014 |
| Ontime Physiotherapy Limited | Health & social care | 2023 |
| OOH Interiors Ltd | Professional & scientific | 2022 |
| Open Circle Community CIC | Health & social care | 2026 |
| Open Dawes Living Ltd | Real estate | 2026 |