| NWD Architects Ltd | Professional & scientific | 1977 |
| Oak Exports (North West) Limited | Other services | 1996 |
| Oak Exports Limited | Wholesale & retail | 1987 |
| Oak Farm (Haughton) Management Company Limited | Households | 1990 |
| Oak Kelsall Hospitality Limited | Hospitality | 2024 |
| Oak Meadow (Penyffordd) Residents Management Company Limited | Households | 2020 |
| Oakdene Building Ltd | Construction | 2005 |
| Oaklands Dental Care Limited | Health & social care | 2019 |
| Oakmere Foods Limited | Hospitality | 2011 |
| Oakmere Timber Limited | Wholesale & retail | 2020 |
| Oaktree Court (Willington) Limited | Households | 1996 |
| Ocean Park Design Ltd | Professional & scientific | 2024 |
| Ohoka Organic Limited | Agriculture & fishing | 2026 |
| Okells Holdings Limited | Financial services | 2018 |
| OLB Consultancy Limited | Professional & scientific | 2022 |
| Old Castle Fields Management Company Limited | Households | 2024 |
| Old Durham Gate and Bishops Walk Residents Management Company Limited | Households | 2024 |
| Old England Vintage Tools & Machinery Ltd | Manufacturing | 2024 |
| Old R Chace Management Company Limited | Households | 2023 |
| Oliver House Management Co. Ltd | Real estate | 2004 |
| Olivia Alexander Hair Ltd | Other services | 2022 |
| Olivia MAY Ltd | Wholesale & retail | 2013 |
| OM Tarporley Limited | Education | 2022 |
| OMC Construction Limited | Construction | 2013 |
| OMC Property Holdings Limited | Real estate | 2018 |
| Omega Peake Ltd | Administrative & support | 2019 |
| Omnia Freelance Ltd | Professional & scientific | 2022 |
| ON Game Ltd | Arts & recreation | 2026 |
| One BIT Media Limited | Information & communication | 2013 |
| One Fine Day Developments Ltd | Real estate | 2014 |
| Onlyfest Ltd | Wholesale & retail | 2024 |
| Onside Talent Limited | Other services | 2025 |
| Ontrak Labs Limited | Professional & scientific | 2023 |
| Ontrak Nutrition Limited | Agriculture & fishing | 2005 |
| Opal Services (Rural West Cheshire) | Health & social care | 2011 |
| Openside 777 Ltd | Professional & scientific | 2008 |
| Optifuel Nutrition Ltd | Manufacturing | 2025 |
| Orchard Gardens (Knaresborough) Residents Management Company Limited | Households | 2021 |
| Orchard Place (Thornton) Management Company Limited | Households | 2023 |
| Oria Web Development Ltd | Information & communication | 2024 |
| Oswestry Waste Paper Limited | Water & waste | 2006 |
| Oulton GIN Ltd | Wholesale & retail | 2024 |
| Oulton View Farm Ltd | Agriculture & fishing | 2009 |
| Oulton Workshop Limited | Wholesale & retail | 2018 |
| Oundle Walk (Oundle) Residents Management Company Limited | Households | 2024 |
| OUT of School Kids Club UK Limited | Education | 2005 |
| Outdoor Sports Hub Ltd | Wholesale & retail | 2023 |
| Outlandergem Limited | Administrative & support | 2024 |
| Overspec Ltd | Other services | 2023 |
| Oxenden Park (Thornden Wood) Management Company Limited | Real estate | 2023 |
| P & a Farren Ltd | Education | 2012 |
| P & C Pavers Ltd. | Construction | 2002 |
| Padel Court Maintenance Cheshire Limited | Construction | 2025 |
| Page Football Development Ltd | Education | 2026 |
| Palmerston Properties (NW) Ltd. | Administrative & support | 2018 |
| Papersort UK Limited | Water & waste | 2010 |
| Paradwys Properties Limited | Real estate | 2021 |
| Parc Aberkinsey Maisonettes (Rhyl Phase 5) Residents Management Company Limited | Households | 2023 |
| Parc Aberkinsy (Rhyl) Resident Management Company Limited | Households | 2022 |
| Parc Bodafon (Llandudno) Resident Management Company Limited | Households | 2024 |
| Parc Bodafon Maisonettes (Llandudno) Residents Management Company Limited | Households | 2024 |
| Parc Tirionfa (Rhuddlan) Management Company Limited | Households | 2019 |
| Parc Y Coed (Old Colwyn) Residents Management Company Limited | Households | 2021 |
| Park Farm (Etwall) Management Company Limited | Households | 2020 |
| Park Gate Village Residents Management Company Limited | Households | 2022 |
| Parklands (Weston Super Mare) Management Company Limited | Households | 2025 |
| Parkwood Property Holdings Limited | Real estate | 2025 |
| Parr Meadows Residents Management Company Limited | Households | 2023 |
| Parsonage Place (Otham) Management Company Limited | Households | 2022 |
| Parsons Croft Management Company Limited | Households | 2022 |
| Pastures Place Management Company Limited | Households | 2022 |
| Paterson & Hill Limited | Wholesale & retail | 2017 |
| Paul Craven Limited | Construction | 2003 |
| Paul Kenyon Design Ltd | Professional & scientific | 2021 |
| PD & RL Fenton | Agriculture & fishing | 2017 |
| Pear Wood Consulting Ltd | Professional & scientific | 2025 |
| Peckforton Hall Farm Management Company Limited | Households | 2001 |
| Pelicano Projects Ltd | Real estate | 2024 |
| Persimmon Gardens (Hindley) Management Company Limited | Households | 2019 |
| Perth Hotel Flats Management Company Limited | Hospitality | 1999 |
| Petrohawk Limited | Professional & scientific | 2013 |
| Phase 1 a Parc Mawr (Penllergaer) Management Company Limited | Households | 2022 |
| PHF Associates LLP | | 2024 |
| Phil Redmond Enterprises Limited | Extraterritorial | 1982 |
| Phoenix Diagnostics Ltd. | Professional & scientific | 2018 |
| Pig&Wolf Limited | Wholesale & retail | 2021 |
| Pinewood Park (Formby) Management Company Limited | Households | 2021 |
| Pipeline Testing Consultants Limited | Construction | 2016 |
| Pirton Fields (Churchdown) Management Company Limited | Households | 2020 |
| PJ Plant Hire (NW) Ltd | Administrative & support | 2023 |
| Planning Property Solutions Ltd | Real estate | 2020 |
| Plas Tirion Farm Limited | Agriculture & fishing | 2014 |
| Platts Meadow (Winsford) Management Company Limited | Households | 2019 |
| Plex Solutions Limited | Professional & scientific | 2016 |
| Plummers Meadow (Halewood) Residents Management Company Limited | Households | 2022 |
| Poet's Rest (Polesworth) Management Company Limited | Households | 2021 |
| Polly and Tots Limited | Wholesale & retail | 2019 |
| Pope Agriculture Ltd | Agriculture & fishing | 2025 |
| Portal Broking Group Limited | Financial services | 2022 |
| Portal Capital LLP | | 2021 |