| Noble Green Investments Ltd | Real estate | 2024 |
| Noble Green QS & DM Ltd | Professional & scientific | 2025 |
| Nolon Limited | Information & communication | 2002 |
| Nooly Limited | Administrative & support | 2008 |
| Nordic Park Ltd. | Wholesale & retail | 1999 |
| Norman Griffiths Limited | Extraterritorial | 2024 |
| North Wales Property Management Limited | Construction | 2019 |
| Norths Village Bakery Ltd | Wholesale & retail | 2023 |
| Northway Arms Limited | Hospitality | 2017 |
| Northway Dental Care Limited | Health & social care | 2012 |
| Northway MOT & Service Ltd | Wholesale & retail | 2012 |
| Northway Trading Estate Management Company Limited | Real estate | 1989 |
| Norton Home Interiors Limited | Construction | 2017 |
| Nova O&N Ltd | Transport & logistics | 2017 |
| Novaqor Ltd | Other services | 2024 |
| NU RAJ Ltd | Hospitality | 2024 |
| Nuakh Holdings Ltd | Real estate | 2026 |
| Nuakh Homes Ltd | Real estate | 2026 |
| Nuakh Ltd | Construction | 2024 |
| Nuakh Property Ltd | Real estate | 2024 |
| NUT Orchard Nutrition Limited | Health & social care | 2014 |
| NW GL20 Limited | Hospitality | 2025 |
| NW3 SPV 1 Ltd | Real estate | 2022 |
| Nymble Analytics Ltd | Professional & scientific | 2018 |
| O&G Supply Chain Services Ltd | Professional & scientific | 2013 |
| O'Brien Wrench and Lowcock Limited | Health & social care | 2001 |
| Oak Cask Distribution Ltd | Wholesale & retail | 2013 |
| Oak Leaf Renovations Ltd | Construction | 2022 |
| Oak Retreats Ltd | Hospitality | 2024 |
| Oakmere Parks Limited | Hospitality | 2024 |
| Oculus Vision Services Ltd | Professional & scientific | 2022 |
| OD People Ltd | Professional & scientific | 2019 |
| Oddball Customs Ltd | Wholesale & retail | 2015 |
| Odessa Motor Company Ltd | Wholesale & retail | 2011 |
| Old Manor Farm Management Company (Alstone) Limited | Households | 2023 |
| Olipops Ltd | Real estate | 2018 |
| Onbrand Apparel Ltd | Manufacturing | 2023 |
| One of One Automotive Limited | Wholesale & retail | 2025 |
| One Source Technology Limited | Manufacturing | 2021 |
| Onfield International Ltd | Wholesale & retail | 2025 |
| Optimum Paint Services Ltd | Construction | 2022 |
| Orchard Blossom Limited | Hospitality | 2024 |
| Orchard Catering Limited | Hospitality | 2007 |
| Orchard Law Limited | Professional & scientific | 2025 |
| Orchard Lean Business Solutions Limited | Professional & scientific | 2015 |
| Orchard Nurseries Enterprises Limited | Transport & logistics | 2024 |
| Orchard Press (Cheltenham) Limited | Manufacturing | 2003 |
| Orchard Press Factory Ltd | Extraterritorial | 2018 |
| Oregon Tool U.K. Limited | Wholesale & retail | 1983 |
| Oriel Property Maintenance Ltd | Construction | 2023 |
| Orion Consultancy Services Limited | Professional & scientific | 2025 |
| OTA Management Limited | Professional & scientific | 2010 |
| Oven Loving Tewkesbury Ltd | Administrative & support | 2022 |
| Over 40 and Thriving Ltd | Real estate | 2023 |
| Overbury Bloodstock Limited | Agriculture & fishing | 2014 |
| Overbury Communications Ltd | Information & communication | 2012 |
| Overbury Farms Limited | Extraterritorial | 2015 |
| Overbury Grasshoppers Limited | Education | 2009 |
| Overbury Nursery Limited | Education | 2009 |
| Overbury Stallions Ltd | Agriculture & fishing | 2003 |
| Ownithealthcare Limited | Health & social care | 2025 |
| Ownzone Space Limited | Real estate | 2018 |
| OX Overland Ltd | Wholesale & retail | 2018 |
| Oxenton Hill Sporting Club Limited | Arts & recreation | 2025 |
| Oxer Advisory Ltd | Professional & scientific | 2018 |
| Oxford Infracare Developments Holdings Limited | Real estate | 2004 |
| Oxford Infracare Developments Limited | Real estate | 2004 |
| Oxford Infracare Lift (1) Limited | Real estate | 2004 |
| Oxford Infracare Lift Holdings (1) Limited | Real estate | 2004 |
| Oxford Infracare Lift Limited | Real estate | 2004 |
| Oxford Property Maintenance Limited | Real estate | 2002 |
| P & J Bayliss Ltd | Administrative & support | 2022 |
| P & S Engineering Services Ltd | Manufacturing | 2008 |
| P a Fire and Security Ltd | Administrative & support | 2019 |
| P Buffery Consulting Limited | Administrative & support | 2026 |
| P H Giles & Co Limited | Professional & scientific | 1972 |
| P.W.W. Limited | Real estate | 1986 |
| Packwood Printers Limited | Manufacturing | 1974 |
| Padme Priya Ltd | Health & social care | 2018 |
| Padsview LLP | | 2013 |
| Paint POT Parties Ltd | Construction | 2024 |
| PAL Electrical Wholesale Limited | Wholesale & retail | 1989 |
| PAM FOX Accountancy Limited | Professional & scientific | 2015 |
| Pamuk Real Estates Ltd | Real estate | 2023 |
| Panacea Corporate Services Limited | Professional & scientific | 2011 |
| Panda Tax Accountancy Services Ltd | Professional & scientific | 2012 |
| Panelwise Limited | Other services | 2026 |
| Parsnips Dog Grooming Limited | Agriculture & fishing | 2025 |
| Partime Limited | Extraterritorial | 1980 |
| Partners (Rentals) Limited | Real estate | 2025 |
| Paul Stephenson Residential Ltd | Real estate | 2017 |
| Pawfecta Ltd | Wholesale & retail | 2022 |
| Pearl of Northway Limited | Hospitality | 2010 |
| Pedigree Pens Limited | Wholesale & retail | 1996 |
| Penmayne Management Company Limited | Households | 2020 |
| Pennyhaven Enterprises Limited | Agriculture & fishing | 2022 |
| Pentenamio Holdings Ltd | Information & communication | 2025 |
| Pentenamio Ltd | Information & communication | 2024 |
| Pentenamio Operations Ltd | Information & communication | 2025 |
| Perfect Fabrications Limited | Manufacturing | 2016 |