| Orchards Electrical Services Ltd | Construction | 2025 |
| Ordo Energy Limited | Construction | 2023 |
| Ordoline UK Limited | Manufacturing | 2021 |
| ORI Global Ltd | Wholesale & retail | 2026 |
| Orion Machinery & Equipment Limited | Manufacturing | 2025 |
| Orion Pumps & Air Equipment Limited | Wholesale & retail | 1992 |
| Oris-Enterprise Ltd | Construction | 2024 |
| Orishirishi Ltd | Hospitality | 2025 |
| Orisun Heights Limited | Real estate | 2023 |
| Orpington Day Nursery & Pre-School Limited | Extraterritorial | 2020 |
| Ortega Consulting Limited | Administrative & support | 2020 |
| OS Designs & Partners Limited | Professional & scientific | 2016 |
| Osafo Ltd | Other services | 2023 |
| OSB Group PLC | Financial services | 2019 |
| Osborne Weller Estate Planning Ltd | Professional & scientific | 2018 |
| Osborne Weller Financial Services Limited | Financial services | 2021 |
| Oseubemsa Limited | Other services | 2014 |
| Oshitech Ltd | Information & communication | 2010 |
| OSJ Dynamics Ltd | Information & communication | 2023 |
| OSJ Partners Ltd | Other services | 2016 |
| OSJ Realtors Ltd | Real estate | 2026 |
| Otium Lake Ltd | Real estate | 2017 |
| Ouddicted Ltd | Wholesale & retail | 2026 |
| OUR Happy Haulage Ltd | Transport & logistics | 2022 |
| OUR House by the Sea Limited | Hospitality | 2013 |
| OUR Rock Housing Solutions Ltd | Real estate | 2023 |
| Ouroboros Financial Planning Limited | Financial services | 2022 |
| Outdoor Buildings UK Ltd | Construction | 2024 |
| OYD Logistics Limited | Wholesale & retail | 2020 |
| Ozengell Quarry LLP | | 2020 |
| P & a Bailey Properties Limited | Real estate | 2024 |
| P & J Jefferson Limited | Professional & scientific | 2009 |
| P & S Anderson (Builders) Limited | Construction | 2014 |
| P Crawford (Kent) Ltd | Construction | 2017 |
| P J and Daughters Limited | Construction | 2011 |
| P J Brown Decorators Ltd | Construction | 2011 |
| P J Butler Ltd | Administrative & support | 2005 |
| P J Premium Funding Limited | Other services | 2002 |
| P M Reeves (Strood) Ltd | Construction | 2023 |
| P M Reeves Ltd | Construction | 2020 |
| P S W Heating & Plumbing Ltd | Construction | 2015 |
| P&B Building Services Limited | Construction | 2016 |
| P&C Carpentry and Building Limited | Construction | 2018 |
| P&J Fryer Limited | Administrative & support | 2024 |
| P&K Windows Limited | Administrative & support | 2010 |
| P&L Hart Properties Limited | Real estate | 2021 |
| P&N Stays Ltd | Real estate | 2025 |
| P&P Autotraders Limited | Wholesale & retail | 2020 |
| P&S Pro Services Ltd | Real estate | 2024 |
| P&W Chemicals Limited | Wholesale & retail | 2021 |
| P&W Universal Holdings Limited | Real estate | 2021 |
| P&W Water Hygiene Ltd | Professional & scientific | 2015 |
| P. & W. Nash (Engineering Services) Limited | Manufacturing | 1990 |
| P.D Civils & Building Ltd | Construction | 2023 |
| P.J. Mullan & Sons (Contractors) Limited | Construction | 1994 |
| P.J. Mullan & Sons (Plant Hire & Sales) Limited | Construction | 1994 |
| P.J. Services Limited | Construction | 1979 |
| P.M Projects Sussex Limited | Professional & scientific | 2018 |
| P.R.I.D.E Care Support UK Ltd | Health & social care | 2020 |
| P.W. Leeman Limited | Wholesale & retail | 1976 |
| P369 Real Estate Ltd | Real estate | 2025 |
| Paddock View (Challock)Management Company Limited | Households | 2019 |
| Page Decorating Ltd | Construction | 2014 |
| Page Plant Services Ltd | Construction | 2007 |
| PAL Property Group Limited | Real estate | 2018 |
| Palladian Media Limited | Information & communication | 2017 |
| Palm Tree Plates Ltd | Hospitality | 2025 |
| Palmers Home Properties Ltd | Real estate | 2020 |
| PAM2 Consultancy Ltd | Professional & scientific | 2022 |
| Pamira Associates Ltd | Information & communication | 2020 |
| PAN London Transport Limited | Transport & logistics | 2022 |
| Panbal Limited | Health & social care | 2018 |
| Panda Colabs Ltd | Professional & scientific | 2018 |
| Papa Holdings Limited | Financial services | 2016 |
| Papercar Consultancy Limited | Administrative & support | 2021 |
| Pappardelle Chef Ltd | Hospitality | 2024 |
| Park Car Wash Strood Ltd | Other services | 2025 |
| Park Farm Plant Ltd | Administrative & support | 2026 |
| Park Valley Leisure Limited | Arts & recreation | 2010 |
| Parker Games Ltd | Wholesale & retail | 2016 |
| Parker Marine Transport Ltd | Transport & logistics | 2019 |
| Parkin Carpentry Services Limited | Construction | 2016 |
| Parkway Energy Management (UK) Ltd | Professional & scientific | 2007 |
| Parkwood Beauty Clinic Ltd | Other services | 2003 |
| Parr Installations Ltd | Construction | 2019 |
| Parrk Consultancy Limited | Information & communication | 2021 |
| Partnerships Working Limited | Professional & scientific | 2024 |
| Passe-Partout Consulting Limited | Professional & scientific | 2000 |
| Passgo Trading Ltd | Construction | 2000 |
| Passive Pro Limited | Wholesale & retail | 2024 |
| Paston Haulage Ltd | Transport & logistics | 2018 |
| PAT Murphy Consultants Limited | Construction | 2013 |
| Patel Engineering Services Limited | Professional & scientific | 2015 |
| Pathway 2 Prosperity International Ltd | Administrative & support | 2019 |
| Pathwayhub Digital Ltd | Information & communication | 2025 |
| Pathways to Independent Living, Learning and Resilience (Pillar) Ltd | Health & social care | 2024 |
| Patmoz Ltd | Information & communication | 2012 |
| Patrick Duff Opticians Limited | Administrative & support | 2007 |
| Patrick Wayne Wealth Management Limited | Financial services | 2016 |
| Paul Edwards Kitchens Ltd | Construction | 2011 |