| Outside Bars (EA) Ltd | Hospitality | 2018 |
| Outside in Building Limited | Administrative & support | 2016 |
| Outsource Consulting Ltd | Professional & scientific | 2022 |
| Outsourced Payroll Consultancy Ltd | Administrative & support | 2019 |
| Outspan Ltd | Administrative & support | 2004 |
| Outt Limited | Professional & scientific | 2020 |
| Outthere Norwich CIC | Health & social care | 2026 |
| Oval Tubes (UK) Limited | Manufacturing | 2001 |
| Ovaview Group Limited | Wholesale & retail | 2017 |
| Overbury Complete Building Service Ltd | Construction | 2019 |
| Overbury Image Limited | Administrative & support | 2021 |
| Overbury Steward Ltd | Professional & scientific | 2017 |
| Overburys Financial Services Limited | Financial services | 2010 |
| Overdale Therapy Ltd | Health & social care | 2025 |
| Overgaard AI Ltd | Professional & scientific | 2025 |
| Overton Technical Services Limited | Professional & scientific | 2018 |
| Overwatch OPS Ltd | Administrative & support | 2025 |
| Oveslab Ltd | Health & social care | 2025 |
| OVH PC Ltd | Construction | 2008 |
| Ovits Oral Care Ltd | Health & social care | 2024 |
| Ovlt Healthcare Ltd | Health & social care | 2022 |
| Owen Powered Access Ltd | Administrative & support | 2011 |
| OWL Barn Limited | Wholesale & retail | 1995 |
| OWL Brand Stationery Limited | Extraterritorial | 2018 |
| Owner Drivers Ltd | Administrative & support | 2010 |
| OWP Holdings Ltd | Financial services | 2019 |
| OX Electrical Services Limited | Construction | 2011 |
| Oxbridge Tutors Online Ltd | Education | 2022 |
| Oxford Oriental Consultants Ltd | Education | 2016 |
| Oxford Stem Ltd | Manufacturing | 2018 |
| Oxford VEG Restaurant Ltd | Hospitality | 2024 |
| Oxfordian College Ltd | Professional & scientific | 2019 |
| Oxifree Global Limited | Wholesale & retail | 2022 |
| Oxley and Langley Investments Limited | Real estate | 2016 |
| Oxlid Ltd | Extraterritorial | 2025 |
| Oxon Security Home Counties UK Limited | Administrative & support | 2007 |
| Oxwich Communications Limited | Professional & scientific | 2004 |
| Oxygen Fit Limited | Arts & recreation | 2010 |
| Oyster Travel Norwich Ltd | Administrative & support | 2012 |
| Ozark Holdings Limited | Construction | 2017 |
| Ozzie's Oinkers Ltd. | Agriculture & fishing | 2019 |
| P & C Building Services Ltd | Construction | 2006 |
| P & D Tank Services Ltd | Construction | 2012 |
| P & K Home Improvements Ltd | Construction | 2021 |
| P & M Devlukia Limited | Professional & scientific | 2024 |
| P & S Organ Supply Company (UK) Ltd | Administrative & support | 2006 |
| P &G Property Group Limited | Real estate | 2025 |
| P a Evans Limited | Financial services | 2013 |
| P a Hire Limited | Administrative & support | 2012 |
| P a White Associates Ltd | Financial services | 2022 |
| P and P Plant Hire Ltd | Administrative & support | 2025 |
| P and S Platt Limited | Hospitality | 2001 |
| P Bowyer Associates Limited | Other services | 1985 |
| P D Drake Housing Ltd | Real estate | 2018 |
| P D S Roofing Limited | Construction | 2007 |
| P D Trading Limited | Wholesale & retail | 2010 |
| P E Mayo Consulting Ltd | Financial services | 2011 |
| P F Furnishings Limited | Manufacturing | 2012 |
| P Grote & Co Limited | Hospitality | 2015 |
| P J Plumbing Heating & Maintenance Limited | Construction | 2003 |
| P J Southgate Limited | Agriculture & fishing | 2002 |
| P J W Johnson Limited | Transport & logistics | 2008 |
| P Ketteringham (Potatoes) Limited | Agriculture & fishing | 1998 |
| P M Pharma Ltd | Manufacturing | 2021 |
| P Merry Limited | Health & social care | 2010 |
| P Morley Construction Services Ltd | Construction | 2019 |
| P N W Carpentry Ltd | Construction | 2008 |
| P P K Factors Limited | Wholesale & retail | 1995 |
| P R G Hornor Limited | Financial services | 2013 |
| P Reid Services Ltd | Transport & logistics | 2024 |
| P Store Ltd | Wholesale & retail | 2025 |
| P Vladi Ltd | Real estate | 2024 |
| P W Angling Ltd | Agriculture & fishing | 2011 |
| P&A Property Investing Ltd | Real estate | 2024 |
| P&D Specialist Services Limited | Construction | 2007 |
| P&H Moore Properties Limited | Real estate | 2025 |
| P&K International Limited | Professional & scientific | 2022 |
| P&L Energy Limited | Manufacturing | 2017 |
| P&P Studio Limited | Construction | 2011 |
| P&R Jones Trading Co Ltd | Construction | 2018 |
| P. & H. Mayhew & SON Limited | Agriculture & fishing | 1994 |
| P. a. T. Pass Ltd | Construction | 2003 |
| P. Barnard Contractor Ltd | Agriculture & fishing | 2025 |
| P. Casey Builders Ltd | Construction | 2006 |
| P. F. Southgate Limited | Agriculture & fishing | 1960 |
| P. Jones Joinery Limited | Construction | 2005 |
| P. Waller (Decorators) Limited | Construction | 1980 |
| P.A. Quantrell Construction Ltd | Construction | 2023 |
| P.A.C. Management Services Limited | Administrative & support | 2017 |
| P.C. Decorating Services Limited | Construction | 2003 |
| P.C.S.W Limited | Hospitality | 2006 |
| P.D. Chapman Limited | Agriculture & fishing | 1936 |
| P.D.Drake Limited | Construction | 2014 |
| P.D.I. (Utilities Design & Management) Ltd | Construction | 1998 |
| P.E.S (East Anglia) Limited | Construction | 2017 |
| P.E.S Properties (East Anglia) Limited | Construction | 2024 |
| P.H.A.T Shellys Ltd | Hospitality | 2024 |
| P.I.P.S. Trustee Limited | Financial services | 1986 |
| P.J. Cozens Limited | Professional & scientific | 2000 |
| P.J. Davey & Co. Ltd | Agriculture & fishing | 2000 |