| Nspb Ventures Ltd | Real estate | 2026 |
| NSR Motors Ltd | Wholesale & retail | 2025 |
| NSV Consulting Ltd | Professional & scientific | 2025 |
| Nswift Limited | Construction | 2025 |
| Nswitch Ltd | Construction | 2025 |
| NT Production Ltd | Hospitality | 1998 |
| NT Styling & Consultancy Ltd | Professional & scientific | 2020 |
| Ntcarz Ltd | Wholesale & retail | 2026 |
| Ntcommerce Ltd | Wholesale & retail | 2026 |
| NTD Services Ltd | Administrative & support | 2025 |
| NTL Electrical Ltd | Construction | 2025 |
| Ntnk Builders Limited | Construction | 2026 |
| Ntoi Ltd | Administrative & support | 2025 |
| NU Concept Solutions Ltd | Information & communication | 1998 |
| NU Lace Limited | Wholesale & retail | 2022 |
| NU Star Engineering Limited | Manufacturing | 1982 |
| Nu-Age Skincare Ltd | Manufacturing | 2021 |
| NUA Electricals Limited | Construction | 2022 |
| Nuels Consult+ Limited | Construction | 2026 |
| Nufocus Trading Ltd | Professional & scientific | 2009 |
| Nuga Tree Ltd | Manufacturing | 2023 |
| Number One a Ltd | Real estate | 2026 |
| Number One Motor Car Parts Ltd | Wholesale & retail | 2022 |
| Number Seventeen Ltd | Real estate | 2021 |
| Number Thirty Five Limited | Real estate | 2021 |
| NUMBER27LAND Ltd | Wholesale & retail | 2024 |
| NUMBER9ALEX Ltd | Real estate | 2024 |
| Numira Solutions Ltd | Professional & scientific | 2023 |
| Numoo Advisory Ltd | Information & communication | 2025 |
| Numpie Accounting Limited | Professional & scientific | 2026 |
| Numtan Thai Ltd | Hospitality | 2019 |
| Nuna Limited | Other services | 2014 |
| NUR Collection Limited | Wholesale & retail | 2024 |
| NUR International Ltd | Wholesale & retail | 2026 |
| NUR Market Ltd | Wholesale & retail | 2022 |
| Nurture: Therapy and Family Wellness CIC | Education | 2025 |
| Nusabiotics Limited | Manufacturing | 2019 |
| Nush Content Creator Ltd | Professional & scientific | 2025 |
| Nusrat BB Ltd | Wholesale & retail | 2026 |
| Nutodbrooks Services Ltd | Health & social care | 2022 |
| Nutravox Ltd | Wholesale & retail | 2025 |
| Nutribe Ltd | Administrative & support | 2025 |
| Nutrimax Limited | Health & social care | 2019 |
| Nuttmeg IT Limited | Information & communication | 2019 |
| Nuur Community CIC | Administrative & support | 2023 |
| Nuvora Ltd | Information & communication | 2026 |
| Nuwave Security Solutions Ltd | Administrative & support | 2026 |
| Nviro Cleantech Limited | Information & communication | 2005 |
| NVN Removals Ltd | Transport & logistics | 2024 |
| NW Van MEN Limited | Transport & logistics | 2020 |
| NW10 Finance Llbb Ltd | Wholesale & retail | 2025 |
| NWO Travel Services Ltd | Transport & logistics | 2025 |
| Nxcmotors Ltd | Wholesale & retail | 2022 |
| Nxzaheer Ltd | Wholesale & retail | 2024 |
| NY Electricals Ltd | Construction | 2025 |
| NYA Rose Ltd | Wholesale & retail | 2023 |
| Nyams Monique Limited | Health & social care | 2013 |
| Nyasha Investments Ltd | Health & social care | 2014 |
| Nykel Consultancy Limited | Health & social care | 2016 |
| Nynys Ltd | Administrative & support | 2023 |
| NZ Accountancy Ltd | Professional & scientific | 2015 |
| Nznuk Ltd | Wholesale & retail | 2025 |
| O and a London Ltd | Hospitality | 2025 |
| O N Beben Limited | Transport & logistics | 2021 |
| O ROW Solutions Ltd | Transport & logistics | 2026 |
| O&G Property Management Ltd | Real estate | 2019 |
| O'Grady Investments Limited | Real estate | 2018 |
| O'Malley Event Services Ltd | Hospitality | 2026 |
| O'Neil Perkins Limited | Manufacturing | 2023 |
| O'Sullivan E&I Technical Services Ltd | Construction | 2022 |
| O.C. Management Limited | Households | 1983 |
| O.J Otto Ltd | Transport & logistics | 2019 |
| O.K.O Services Ltd | Administrative & support | 2023 |
| O.M.B.Cleaning Ltd | Administrative & support | 2018 |
| O2I Investments Ltd | Financial services | 2015 |
| OAA Music Limited | Information & communication | 2014 |
| OAG Aviation Worldwide Limited | Administrative & support | 2013 |
| Oak & Pearl Ltd | Wholesale & retail | 2025 |
| Oak and Abbey Estates Ltd | Real estate | 2026 |
| Oak City Outreach CIC | Health & social care | 2024 |
| Oak Community Services CIC | Health & social care | 2022 |
| Oak Creations Ltd | Arts & recreation | 2024 |
| Oak Road Hatter Ltd | Financial services | 2024 |
| Oak Teachers Ltd | Administrative & support | 2024 |
| Oakbeech Investments Limited | Real estate | 2015 |
| Oakbrooke Investments Limited | Real estate | 2018 |
| Oakdale Construction Services Ltd | Construction | 2025 |
| Oakdeane Investments Limited | Real estate | 2008 |
| Oakdeane Property Investments Limited | Real estate | 2017 |
| Oakes Finance Limited | Financial services | 2003 |
| Oakfield Motors Ltd | Wholesale & retail | 2025 |
| Oakfield Refurbishments Limited | Construction | 2014 |
| Oakhill View Management Company Limited | Households | 2005 |
| Oaklandsse Ltd | Information & communication | 2015 |
| Oakley Flowers and Produce Limited | Wholesale & retail | 2015 |
| Oakley Legal Services Ltd | Professional & scientific | 2010 |
| Oakley Lodge Care Home Ltd | Health & social care | 2010 |
| Oakline Wholesales Ltd | Wholesale & retail | 2026 |
| Oakmont Elite Ltd | Arts & recreation | 2026 |
| Oaktree Drylining Limited | Construction | 2021 |