| NBS Technologies Limited | Information & communication | 2025 |
| Neil Barnard Installations Limited | Construction | 2022 |
| Neil Harker Limited | Construction | 2002 |
| NET Pharm Ltd | Wholesale & retail | 2023 |
| Nettleton House Retreat and Stables Limited | Hospitality | 2020 |
| Netzero Renewables Group Ltd | Professional & scientific | 2024 |
| New HUA Ltd | Hospitality | 2026 |
| Newtoft Business Centre Management Company Limited | Extraterritorial | 1999 |
| Newtoft Management Company Limited | Households | 1996 |
| Nick Young Tractor Parts Limited | Wholesale & retail | 2011 |
| Nickerson Brothers Ltd. | Wholesale & retail | 1985 |
| Nickerson R.P.B. Limited | Professional & scientific | 1962 |
| Nickerson UK Limited | Professional & scientific | 1956 |
| Nickys Nice & Naughty Ltd | Manufacturing | 2018 |
| Nicola Dixey Ltd | Wholesale & retail | 2019 |
| Nigel Atkins Haulage Ltd | Transport & logistics | 2014 |
| Nigel Skinner Financial Advisers Limited | Financial services | 2009 |
| NJP Consultancy Ltd | Professional & scientific | 2023 |
| NKR Management Company Ltd | Households | 2021 |
| NMR Dynamics Ltd | Information & communication | 2025 |
| Noble Oak Investments Ltd | Real estate | 2025 |
| Noble Oak Properties Ltd | Households | 2025 |
| Noel Taylor Financial Consulting Limited | Professional & scientific | 2015 |
| Nonex Limited | Extraterritorial | 2014 |
| Nonex PBC Limited | Extraterritorial | 2012 |
| Nonex Systems Limited | Mining & quarrying | 2012 |
| Norton Minster Estates Ltd | Real estate | 2021 |
| Norton Power Partnership LLP | | 2020 |
| Nova Trading Group Ltd | Wholesale & retail | 2025 |
| NSB Construction (Lincoln) Limited | Construction | 2012 |
| Nsfa Holdings Limited | Financial services | 2022 |
| Number 2A Commerce Square Nottingham Management Co. Limited | Real estate | 1989 |
| O Watson (Contracting) Ltd | Real estate | 2024 |
| O'Brien Logistics Limited | Construction | 2022 |
| O'Brien Property Limited | Real estate | 2019 |
| O.S. Motor Traders Limited | Wholesale & retail | 2021 |
| Oaklane Developments Ltd | Construction | 2022 |
| Oakmont Distribution Ltd | Wholesale & retail | 2020 |
| OFF Grid EV Charging Limited | Manufacturing | 2025 |
| OIL Tank Replacement Services Limited | Construction | 2004 |
| Olly Williams Racing Limited | Arts & recreation | 2015 |
| Olona Build Ltd | Construction | 2024 |
| ON Radar Limited | Professional & scientific | 2016 |
| One 4 Pack Limited | Manufacturing | 2015 |
| One Sky Aviation LLP | | 2006 |
| One World Education Ltd | Education | 2026 |
| Oppen Studio Ltd. | Professional & scientific | 2014 |
| Orbis Distribution Limited | Transport & logistics | 2017 |
| Orbitprime Developments Limited | Households | 1988 |
| Orchard Close Estate Management Ltd | Real estate | 2019 |
| Orford Estates Limited | Real estate | 2017 |
| OT & Training Services Ltd | Health & social care | 2025 |
| Otaku Lincoln Ltd | Wholesale & retail | 2022 |
| Otby VS Limited | Professional & scientific | 2025 |
| Over the Moon Design Limited | Wholesale & retail | 2009 |
| Overland Leisure Ltd | Construction | 2019 |
| Owersby Farm Limited | Agriculture & fishing | 2005 |
| OZ Cloud Limited | Professional & scientific | 2014 |
| P & B Hodgson and Sons Limited | Agriculture & fishing | 2005 |
| P T W B Limited | Construction | 2012 |
| P.B.C. Enterprises Limited | Agriculture & fishing | 1999 |
| P.G.R Automotive Services Ltd | Wholesale & retail | 2014 |
| P.I.C. International Ltd | Wholesale & retail | 2018 |
| P7 Investment Limited | Financial services | 2021 |
| Panda Palace 595 Limited | Hospitality | 2023 |
| Pangolin-Services Limited | Information & communication | 2001 |
| Parallel Flooring Accessories Limited | Manufacturing | 1996 |
| Paramount Global Retail Ltd | Wholesale & retail | 2021 |
| Parkies Wine Bar Limited | Professional & scientific | 2014 |
| Parkview (Market Rasen) Limited | Wholesale & retail | 2000 |
| Parkview Properties (Market Rasen) Limited | Real estate | 2017 |
| Parnell Percival Holdings Limited | Administrative & support | 2019 |
| Parquet Parquet Limited | Construction | 2014 |
| Patrick Fitzgerald Limited | Education | 2021 |
| Patrick Fitzgerald Media Limited | Education | 2021 |
| Patrick Fitzgerald Publishing UK Limited | Education | 2021 |
| Patton House Farm Limited | Agriculture & fishing | 2023 |
| Paul Roberts Builders Limited | Construction | 2004 |
| Paul Sellars Limited | Construction | 2008 |
| Paverpol UK Ltd | Wholesale & retail | 2016 |
| Peacock Inn (Lincoln) Ltd | Hospitality | 2019 |
| Pearson's Family Investments | Financial services | 2023 |
| PEM Corporation Limited | Financial services | 2025 |
| Pemec E&I Limited | Construction | 2025 |
| Pemec OIL & GAS Limited | Construction | 2018 |
| Pemec Refrigeration Limited | Construction | 2023 |
| Pemec Solutions Limited | Administrative & support | 2021 |
| Pentagon Construction & Interiors Limited | Construction | 2019 |
| Pepper Investments Limited | Construction | 2002 |
| Perkins George Mawer & Co. Limited | Real estate | 2018 |
| Pest & Hygiene Services Ltd | Agriculture & fishing | 2023 |
| Pete Cook Limited | Manufacturing | 2010 |
| Peter J. Green & Co Ltd | Professional & scientific | 2026 |
| Peterborough Signs Limited | Other services | 2014 |
| PF Refrigeration Ltd | Construction | 2019 |
| Phoenix 21 Limited | Education | 2011 |
| Phoenix Consulting Services Limited | Professional & scientific | 2025 |
| Phoenix Trading Group Ltd | Wholesale & retail | 2025 |
| Phototitles Limited | Wholesale & retail | 2006 |
| Pilot House Ltd | Information & communication | 2022 |