| Omega Kitchens (Leicestershire) Limited | Manufacturing | 2002 |
| Omnd Ltd | Real estate | 2022 |
| OMS Construction Ltd | Construction | 2017 |
| ON the Brink Catering Limited | Hospitality | 2011 |
| One 2 One Sign Solutions Ltd | Professional & scientific | 2009 |
| One Love Pizza Ltd | Hospitality | 2023 |
| Onelife Wealth Advice Ltd | Professional & scientific | 2015 |
| Onescotteh Ltd | Health & social care | 2026 |
| Online Profiling Limited | Information & communication | 2001 |
| Online Wealth Advice Ltd | Financial services | 2015 |
| Open Point Ltd | Construction | 2024 |
| Open Source IT Solutions Ltd | Information & communication | 2025 |
| Operational Systems Technology Limited | Information & communication | 2016 |
| OPM Stocking Ltd | Wholesale & retail | 2022 |
| Optical Clinic RX Ltd | Health & social care | 2022 |
| Optimus Oral Surgery Ltd | Health & social care | 2017 |
| Orca Networks Ltd | Construction | 2024 |
| Orchard Prescribing Limited | Health & social care | 2025 |
| Ordogs Ltd | Transport & logistics | 2011 |
| Origin Environmental Ltd | Professional & scientific | 2021 |
| Orrin Ltd | Real estate | 2023 |
| Orthogas Limited | Health & social care | 2012 |
| Osaka Investments (Europe) Limited | Real estate | 2009 |
| Osborne Medical Imaging Ltd | Health & social care | 2024 |
| Osbornes Carpentry & Building Ltd | Construction | 2023 |
| OSG (GB) Limited | Professional & scientific | 2000 |
| OSN Stocktakers Ltd | Professional & scientific | 2019 |
| Oxford Property Management LLP | | 2004 |
| P & F Capital Ltd | Financial services | 2021 |
| P & F Plant Limited | Administrative & support | 2007 |
| P & J Amusement Machines Limited | Extraterritorial | 2023 |
| P a Dodd Ltd | Wholesale & retail | 2008 |
| P C Diabetes Limited | Health & social care | 2016 |
| P Conboy Limited | Other services | 2009 |
| P Day Developments Limited | Construction | 2002 |
| P Kukreja Ltd | Professional & scientific | 2020 |
| P Mcentee Ltd | Professional & scientific | 2024 |
| P&F Environmental Services Limited | Professional & scientific | 2020 |
| P3 Delivery Ltd | Other services | 2014 |
| Packable Limited | Transport & logistics | 2007 |
| Packetlink Limited | Administrative & support | 2013 |
| Pade Industries Limited | Administrative & support | 2013 |
| Paediatric Allergy Medical Services Ltd | Health & social care | 2025 |
| PAINT2PANEL Services Ltd. | Wholesale & retail | 2016 |
| Paka Properties Ltd | Real estate | 2023 |
| Pallant Psychological Services Limited | Real estate | 2005 |
| Panchal Healthcare Ltd | Health & social care | 2016 |
| Panda Presents Ltd | Information & communication | 2024 |
| Paragon Aesthetic Services Ltd | Health & social care | 2022 |
| Parfocal Ltd | Information & communication | 2025 |
| Pari Associates Limited | Other services | 2009 |
| Parimatch United Investments Limited | Information & communication | 2014 |
| Parrian Properties Limited | Real estate | 2020 |
| Parsons Group Limited | Wholesale & retail | 2022 |
| Pathready Ltd | Health & social care | 2025 |
| Patil Medical Consultancy Ltd | Health & social care | 2023 |
| Patrick Musto Limited | Other services | 2009 |
| Paul Brewin Electrical Ltd | Construction | 2017 |
| Paul Plant Transport Ltd | Transport & logistics | 2017 |
| Paul Taggar Ltd | Manufacturing | 2012 |
| Paulbyby Transport Ltd | Transport & logistics | 2013 |
| Pdil Holdings Limited | Real estate | 2019 |
| Peak District Leisure Ltd | Hospitality | 2018 |
| Pear Tree Fields Farm Ltd | Agriculture & fishing | 2017 |
| Pennard Commercial Services Ltd | Real estate | 1988 |
| People Practice Partners Limited | Administrative & support | 2022 |
| Perera Consulting Limited | Professional & scientific | 2024 |
| Perera Property Investments Ltd | Real estate | 2018 |
| Perfect Planning Architectural Services Limited | Professional & scientific | 2018 |
| Perfectus Beauty Limited | Health & social care | 2022 |
| Perihan ALI Limited | Other services | 2010 |
| Perkins Plant Hire Limited | Administrative & support | 2025 |
| Personalised Treasures Ltd | Wholesale & retail | 2022 |
| Petals Polly Flowers Ltd | Wholesale & retail | 2012 |
| Pete Rigden Ltd | Transport & logistics | 2022 |
| Petram Mining Solutions Ltd | Wholesale & retail | 2025 |
| Pettitts Pre-School Ltd | Health & social care | 2015 |
| PGS Estates Limited | Other services | 2016 |
| Phillips Project Services Ltd | Professional & scientific | 2022 |
| Physique Club Limited | Arts & recreation | 2024 |
| PI Shelley Limited | Wholesale & retail | 2025 |
| Piddington Associates Limited | Other services | 2015 |
| Pinfold Projects Ltd | Construction | 2011 |
| Pinfold Property Holdings Limited | Real estate | 2018 |
| Pinnacle Finance Solutions Ltd | Professional & scientific | 2022 |
| Pintle Projects Limited | Professional & scientific | 2020 |
| Piquet Construction Limited | Construction | 2015 |
| Pixel Peek Ltd | Health & social care | 2023 |
| PJ Hutchinson & SON (Holdings) Limited | Financial services | 2013 |
| PJK Consultancy and Training Limited | Administrative & support | 2010 |
| PK Car Wash Limited | Other services | 2012 |
| PK Pressure Washer Sales and Servicing Limited | Manufacturing | 2019 |
| Planet Consultancy Services Ltd | Professional & scientific | 2022 |
| Plant Check Ltd | Information & communication | 2025 |
| Plastikcity Ltd | Administrative & support | 2012 |
| Playscapes Design Limited | Construction | 2010 |
| Pmntransport Ltd | Transport & logistics | 2018 |
| POD Digital Limited | Information & communication | 2022 |
| POD Digital Marketing Limited | Information & communication | 2016 |
| POD Digital Marketing Two Limited | Information & communication | 2018 |