| North Notts Sailplanes Ltd | Manufacturing | 2017 |
| North Notts Trucks Limited | Wholesale & retail | 2010 |
| Northern Nests Ltd | Real estate | 2019 |
| Northern Specialised Site Services Limited | Real estate | 1977 |
| Northfield Services (Retford) Limited | Other services | 2014 |
| Nottinghamshire Surveyors LLP | | 2019 |
| Notts Estates Limited | Agriculture & fishing | 1997 |
| Novus Marketing Limited | Administrative & support | 2018 |
| NQ Media Limited | Information & communication | 2013 |
| NRA Consulting Services Ltd | Professional & scientific | 2024 |
| NRG Commercials Limited | Transport & logistics | 2007 |
| NS Advisory Services Ltd | Professional & scientific | 2021 |
| Ntec Electrical Ltd | Construction | 2016 |
| Nuroom Consultancy Limited | Construction | 2026 |
| NW Heating Contracts Ltd | Construction | 2018 |
| O & P Plastering Ltd | Construction | 2021 |
| O&Lsurfacing Limited | Construction | 2012 |
| O.E. Removals Ltd | Transport & logistics | 2018 |
| Oakdale Brick Garages Ltd | Construction | 2024 |
| Oakdale Homes Limited | Construction | 1994 |
| Oakdale Properties Limited | Real estate | 2011 |
| Oaklands Estate Management Limited | Real estate | 2011 |
| Oaks Parc Ltd | Real estate | 2025 |
| Oakwell Landscapes Design and Construction Ltd | Construction | 2022 |
| Obsidia Group (UK) Ltd. | Wholesale & retail | 2012 |
| Obsidia Properties Ltd | Real estate | 2023 |
| Ocean Finest Foods Ltd | Wholesale & retail | 2009 |
| Octagon Financial Services Limited | Financial services | 2011 |
| Odessa Promotions Ltd | Administrative & support | 2020 |
| Ogle Building Contracts Limited | Construction | 2022 |
| OJB Studio Ltd | Professional & scientific | 2024 |
| Old Walled Gardens Management Company Limited | Real estate | 2013 |
| Olive Homes Ordsall Limited | Households | 2019 |
| Olive Tree Law Limited | Professional & scientific | 2019 |
| Olympus Scaffolding Services Ltd | Construction | 2025 |
| Omega Vehicles Ltd | Administrative & support | 2023 |
| Omnivale Limited | Real estate | 1997 |
| Online Mortgages UK Limited | Financial services | 2004 |
| Only Floors Ltd | Construction | 2023 |
| Open Door Property Holidays Limited | Hospitality | 2022 |
| Open Door Property Lettings Limited | Real estate | 2014 |
| Open Door Property Limited | Real estate | 2012 |
| Open Kitchen Takeaway Ltd | Hospitality | 2023 |
| Ops-Services Limited | Other services | 2006 |
| Optimum Consult Ltd | Professional & scientific | 2019 |
| Optimus Medical Limited | Wholesale & retail | 2012 |
| Optimus SPV Limited | Information & communication | 2013 |
| Oracle Facilities Management Ltd | Administrative & support | 2019 |
| Orangeaid Limited | Information & communication | 1999 |
| Ordsall Properties Ltd | Real estate | 2021 |
| Orinj Property Management Limited | Real estate | 2025 |
| Osberton Stud Limited | Agriculture & fishing | 2002 |
| Osmax Building & Hard Landscape Limited | Construction | 2021 |
| OTS (Retford) Ltd | Administrative & support | 2024 |
| Otter & Sage Ltd | Manufacturing | 2026 |
| OUT N About Mobility Ltd | Wholesale & retail | 2005 |
| Over Coals Ltd | Hospitality | 2024 |
| Ownabit Ltd | Real estate | 2024 |
| Oxify (Leeds) Ltd | Health & social care | 2021 |
| Oxify (Manchester) Ltd | Health & social care | 2022 |
| Oxify (Retford) Limited | Health & social care | 2023 |
| Oxify Gateshead (Team Valley) Ltd | Health & social care | 2023 |
| Oxify Pinnacle Ltd | Health & social care | 2023 |
| Oxify York (Clifton Moor) Ltd | Health & social care | 2023 |
| Ozcafe DE Bella Ltd | Hospitality | 2023 |
| P & D Investments UK Ltd | Wholesale & retail | 2000 |
| P & L Farming Partnership Ltd | Agriculture & fishing | 2018 |
| P & S Outdoor Timber Products Limited | Manufacturing | 2021 |
| P and P Properties Notts Ltd | Construction | 2026 |
| P Homan Limited | Agriculture & fishing | 2016 |
| P Houghton Limited | Wholesale & retail | 2006 |
| P Rossington Limited | Real estate | 2002 |
| P&S Elliott Holdings Ltd | Financial services | 2025 |
| P.T.J. Technical Services Limited | Construction | 1996 |
| P.W. Broadberry Farms Limited | Agriculture & fishing | 1988 |
| PAB Consultancy Services Limited | Administrative & support | 2024 |
| Paintman Paint Limited | Manufacturing | 2013 |
| Panda Prospects Limited | Hospitality | 2019 |
| Papillon Loisir Limited | Hospitality | 2018 |
| Park Broom Homes (Spofforth) Limited | Real estate | 2001 |
| Parkforge Ltd | Transport & logistics | 2025 |
| Parkside Autos Limited | Wholesale & retail | 2003 |
| Partner Property Ltd | Households | 2025 |
| Partners in Grime Ltd | Administrative & support | 2026 |
| Pathoshield Ltd | Manufacturing | 2020 |
| Paul Clark Contracting Services Limited | Administrative & support | 2004 |
| Paul Ferguson Electrical Ltd | Construction | 2023 |
| PB Leisure Mobile Technician Limited | Wholesale & retail | 2025 |
| PBD Enterprises Ltd | Real estate | 2014 |
| PBW Property Services Ltd | Construction | 2013 |
| PC Advanced Motorcycle Training Limited | Education | 2017 |
| PC Services (Nottinghamshire) Ltd | Health & social care | 2022 |
| PCH Deliveries Limited | Other services | 2025 |
| Peak Performance Roofing Services Ltd | Construction | 2025 |
| Peartree Associates Limited | Professional & scientific | 2002 |
| Pejunto Ltd | Wholesale & retail | 2016 |
| Pennington's Property Company Ltd | Real estate | 2022 |
| Percival Ernest Ltd | Information & communication | 2019 |
| Performance Hub Theatre School Limited | Arts & recreation | 2021 |
| Perigon Search Ltd | Administrative & support | 2019 |