| Nicola Anne Ltd | Manufacturing | 2012 |
| Ninety Degrees Marketing Ltd | Administrative & support | 2014 |
| Nivala Research Limited | Manufacturing | 2023 |
| Njfca Ltd | Information & communication | 2023 |
| NO Half Measures PUB Co Stoney Stanton Limited | Hospitality | 2017 |
| NO Half Measures PUB Company NO.3 Limited | Hospitality | 2019 |
| Nora Landscapes Ltd | Construction | 2025 |
| Nordic Black Limited | Financial services | 2018 |
| Northants HOG Roast Ltd | Hospitality | 2019 |
| Northforge X Limited | Transport & logistics | 2012 |
| Norton Gardens Management Company Ltd | Households | 2022 |
| Norton Grounds Limited | Administrative & support | 2022 |
| Nourish Learning and Development Limited | Professional & scientific | 2009 |
| Nouveau Corporate Solutions Ltd | Professional & scientific | 2019 |
| Nova Wellbeing Ltd | Information & communication | 2025 |
| Novaream Ltd | Wholesale & retail | 2024 |
| Novel Ideas Promotion Ltd | Professional & scientific | 2015 |
| NPX Ltd | Other services | 2025 |
| NQ Zebraworks Limited | Information & communication | 2000 |
| NRA Capital Investments Limited | Financial services | 2026 |
| NS and PS Developments (UK2) Limited | Real estate | 2018 |
| Nuclear Engineering Supply Chain (Birmingham) Limited | Manufacturing | 2009 |
| Numbers Sense Ltd | Professional & scientific | 2026 |
| Nuneaton Launderette Limited | Other services | 2020 |
| Nuneaton Property Company Limited | Real estate | 1937 |
| Nurture and Grow Nursery Ltd | Education | 2022 |
| Nutcha Hinckley Ltd | Health & social care | 2023 |
| Nutts Lane Freehold Company Limited | Households | 2024 |
| NXG Innova Techlabs Ltd | Information & communication | 2025 |
| O.Hughes Electrical Ltd | Construction | 2023 |
| Oak & Stone Carpentry & Plumbing Ltd | Manufacturing | 2025 |
| Oakandash Limited | Extraterritorial | 2015 |
| OC Property Investments Ltd | Real estate | 2020 |
| Ocean LED Marine Limited | Manufacturing | 2014 |
| Octanauts Ltd | Education | 2017 |
| Offo Limited | Wholesale & retail | 2025 |
| OHM (Hinckley) Limited | Extraterritorial | 2018 |
| Ojlets Limited | Real estate | 2026 |
| Okuma UK Limited | Professional & scientific | 2011 |
| Okvin Group Limited | Professional & scientific | 2021 |
| Okvin Group Technology Ltd | Mining & quarrying | 2021 |
| Old Dalby Residents Company Limited | Households | 2000 |
| Olive & Co Property Limited | Real estate | 2026 |
| Ollila Law Limited | Professional & scientific | 2011 |
| OLP Holdings Ltd | Real estate | 2025 |
| Olympus Eyewear (Wholesale) Ltd | Wholesale & retail | 2012 |
| ON Call Home Repairs Ltd | Construction | 2025 |
| ON PAR Catering Ltd | Hospitality | 2024 |
| ON Site Industrial Limited | Wholesale & retail | 2003 |
| ON Time Recruitment Ltd | Administrative & support | 2023 |
| One Life Mortgages Ltd | Financial services | 2023 |
| One Roof Financial LLP | | 2008 |
| Only Educational Ltd | Education | 2021 |
| Onyx (2002) Limited | Financial services | 2002 |
| Open Hand Sourcing Ltd | Wholesale & retail | 2025 |
| Open Thinking Partnership | Education | 2012 |
| Optometry Ltd | Wholesale & retail | 2011 |
| Orange Auctions Limited | Wholesale & retail | 2025 |
| Orange Peel Industries Ltd | Professional & scientific | 2018 |
| Orange Sunrise Limited | Professional & scientific | 2025 |
| Orchard END Nursery Ltd | Education | 2015 |
| Orliant Limited | Information & communication | 2013 |
| Orton Road Apartments Management Company Limited | Households | 2007 |
| Orton Shaw Limited | Professional & scientific | 2025 |
| Oryx Safety Management Ltd | Professional & scientific | 2025 |
| OUR House Your Home Limited | Real estate | 2017 |
| Over the Top Textiles Limited | Other services | 1997 |
| OWL Administration Services Ltd | Extraterritorial | 2014 |
| Own Game Ltd | Wholesale & retail | 2026 |
| Oxford Grange Limited | Real estate | 2012 |
| P & H Hatton Investments Limited | Real estate | 2025 |
| P & P Automotive Limited | Wholesale & retail | 2020 |
| P Holt Engineering Ltd | Professional & scientific | 2011 |
| P Hughes Holdings Ltd | Financial services | 2021 |
| P.D. Windows Ltd | Construction | 2019 |
| P.G. Developments Coventry Ltd | Construction | 2014 |
| PA Trustees Ltd | Professional & scientific | 2010 |
| Page Denim Designs Ltd | Wholesale & retail | 2004 |
| Paint TEC Solutions Ltd | Manufacturing | 2023 |
| Pamar UK Ltd | Transport & logistics | 2011 |
| Pane E Gusto Ltd | Hospitality | 2024 |
| Papplewick Property Management Limited | Construction | 2026 |
| Paragon Fire Limited | Construction | 2025 |
| Paramount Building Contractors Limited | Construction | 2013 |
| Park Rugby Limited | Arts & recreation | 2019 |
| Parker-Mead Limited | Wholesale & retail | 2014 |
| Parkhub.App Limited | Information & communication | 2025 |
| Parkview Accounting Solutions Ltd | Professional & scientific | 2026 |
| Parris LLP | | 2018 |
| Pashabox Limited | Wholesale & retail | 2012 |
| Pasific Foods Limited | Hospitality | 2025 |
| Patriot Motorcycles Limited | Extraterritorial | 2009 |
| Paul Cordingley Limited | Other services | 2002 |
| Paul Jordan Consultants Ltd | Information & communication | 2025 |
| Paul Noble - Land & Rail Services Limited | Construction | 2014 |
| Paul Randle Developments Ltd | Construction | 2020 |
| Paynes Garage(Holdings) Limited | Professional & scientific | 1965 |
| Paynes Garages Limited | Wholesale & retail | 1947 |
| PB Project Services Ltd | Construction | 2020 |
| PCA Financial Consultancy Limited | Professional & scientific | 2018 |