| One Wirral CIC | Other services | 2019 |
| Onhold Studio Connect Ltd | Information & communication | 2007 |
| Onhold Studio Ltd | Information & communication | 2007 |
| Onnix Performance Ltd | Arts & recreation | 2025 |
| Onyx Interiors Ltd | Professional & scientific | 2025 |
| Openhouse Products Limited | Manufacturing | 1992 |
| Opes Properties and Investments Limited | Real estate | 2019 |
| Opman Limited | Information & communication | 2025 |
| Optimised Energy Solutions Limited | Administrative & support | 1998 |
| Opto (UK) Limited | Wholesale & retail | 2009 |
| Opulent Home Improvements Limited | Households | 2022 |
| Opulla Ltd | Construction | 2019 |
| Orbit Opulence Ltd | Wholesale & retail | 2025 |
| Ordinaries Limited | Extraterritorial | 2023 |
| Oremus Group Limited | Professional & scientific | 2011 |
| Oremus UK Limited | Administrative & support | 2016 |
| Orgafuel Ltd | Other services | 2025 |
| Osah Property Solution Ltd | Professional & scientific | 2021 |
| OSG Healthcare Ltd | Health & social care | 2023 |
| Osprey Barristers Ltd | Professional & scientific | 2021 |
| Ottor Ltd | Manufacturing | 2023 |
| OUR Properties NW Ltd | Administrative & support | 2026 |
| Outright Construction Ltd | Construction | 2025 |
| Outstanding Holdings Ltd | Financial services | 2022 |
| Overrock Ltd | Wholesale & retail | 2023 |
| Owens Enterprise Motors Limited | Wholesale & retail | 2023 |
| Owens Express Motors Limited | Wholesale & retail | 2014 |
| OWS Properties Limited | Real estate | 2026 |
| Oxton Booze Retail Ltd | Wholesale & retail | 2020 |
| Oxton Court Prenton Ltd | Real estate | 2020 |
| Oxton Estates Ltd | Administrative & support | 2009 |
| Oyinda Civils UK Ltd | Construction | 2025 |
| P & a Precision (Engineering) Limited | Manufacturing | 1988 |
| P & a Precision (Holdings) Ltd. | Professional & scientific | 2007 |
| P & M Plumbing Limited | Construction | 2003 |
| P Cross Engineering Ltd | Professional & scientific | 2023 |
| P Jones Groundworks Ltd | Construction | 2025 |
| P Omara Wind Limited | Administrative & support | 2025 |
| P&C Transport Ltd | Transport & logistics | 2025 |
| P&M Property (NW) Limited | Real estate | 2022 |
| P-L-E-N-T-Y-S-A-D-Z-A Ltd | Health & social care | 2024 |
| P.A.S GAS Services Limited | Construction | 2021 |
| P.D. Foods (Wholesale) Limited | Wholesale & retail | 1986 |
| P.E.S. (NW) Ltd | Manufacturing | 1997 |
| P.M. Nunns Associates Limited | Professional & scientific | 1978 |
| PA Pathway Homes Limited | Real estate | 2015 |
| Paisley's Emporium Limited | Wholesale & retail | 2004 |
| PAK DEE Thai Massage Ltd | Other services | 2024 |
| Panda Care Ltd | Health & social care | 2018 |
| Paperless Solutions Limited | Administrative & support | 2013 |
| Paragon Imports Ltd | Wholesale & retail | 2017 |
| Parent Compass Ltd | Professional & scientific | 2025 |
| Pareto (Holdings) Limited | Professional & scientific | 2004 |
| Pareto Retail Limited | Wholesale & retail | 2001 |
| Park Card Marketing Services Limited | Administrative & support | 2005 |
| Park Fitness Wirral Ltd | Arts & recreation | 2023 |
| Park Group Ltip Trustee Limited | Financial services | 2012 |
| Parkgate Medico-Legal Services Limited | Administrative & support | 2007 |
| Parle's Estates Limited | Real estate | 2021 |
| Pasha Barber 01 Limited | Other services | 2021 |
| Pass Technology Ltd | Professional & scientific | 2018 |
| Passingham Limited | Administrative & support | 2006 |
| Pathway Coaching Solutions Ltd | Education | 2025 |
| Paul Ah-Thion Limited | Information & communication | 2010 |
| Paul Ford Engineering Limited | Manufacturing | 2005 |
| Paul Greenwood Photography Ltd | Professional & scientific | 2019 |
| Pauline Quinn Hospitality Ltd | Hospitality | 2023 |
| Pausha Ltd | Hospitality | 2020 |
| Pawesome Pet Sits Ltd | Other services | 2022 |
| Pawesome Walkies Ltd | Other services | 2018 |
| PAX Clothing Ltd. | Wholesale & retail | 2021 |
| Paxton Pipe Services Ltd | Construction | 2026 |
| PAY2STAY (North West) Ltd | Agriculture & fishing | 2015 |
| Pdmsg Ltd | Hospitality | 2026 |
| Peak Developments (Wirral) Limited | Construction | 2019 |
| Pebble Eleven Limited | Wholesale & retail | 2023 |
| Pegasus Developments Ltd | Construction | 2018 |
| Pegasus Plastering Limited | Construction | 2013 |
| Pen-Y-Ffrith Caravan Park Limited | Hospitality | 2016 |
| Pendleton Care Limited | Health & social care | 2004 |
| Penga International Ltd | Transport & logistics | 2024 |
| Peninsula Brew Co Ltd | Manufacturing | 2024 |
| Peninsula Gardening Services Limited | Administrative & support | 2018 |
| Peninsula Motorcycles Ltd | Wholesale & retail | 2018 |
| Peninsula Pools Ltd | Administrative & support | 2018 |
| Peninsula Travel Wirral Ltd | Transport & logistics | 2024 |
| Peninsular Breweries Limited | Extraterritorial | 2013 |
| Penny ROO Optical Ltd | Wholesale & retail | 2024 |
| Pensby Plumbing & Plastering Limited | Construction | 2022 |
| Penwaig Limited | Construction | 2025 |
| Penway Developments Ltd | Construction | 2003 |
| Peptify Labs Ltd | Wholesale & retail | 2026 |
| Peptiq Ltd | Professional & scientific | 2026 |
| Perfectum Property Maintenance Services Ltd | Financial services | 2022 |
| Perritt Anaesthetics Limited | Health & social care | 2021 |
| Perro Genetics Limited | Wholesale & retail | 2025 |
| Pershore House Management Company Limited | Real estate | 2008 |
| Person Centred Coaching Limited | Administrative & support | 2018 |
| Personal Pride Ltd | Other services | 2023 |
| Peter Bigyan Ltd | Health & social care | 2023 |