| Oakensen Limited | Professional & scientific | 2010 |
| Oaktree Court (Bedford Park) Limited | Real estate | 2006 |
| Oakwood House RTM Company Limited | Administrative & support | 2012 |
| Oakwood Prestige Cars Limited | Wholesale & retail | 2013 |
| OB Consulting Limited | Professional & scientific | 2000 |
| Ocean 36 Limited | Real estate | 2019 |
| ODY Ventures Limited | Administrative & support | 2014 |
| Odyssey 200 Ltd | Administrative & support | 2006 |
| Old Milestone Nursery Limited | Agriculture & fishing | 2004 |
| Old Time Dance Society Limited | Arts & recreation | 2007 |
| Oliver Pietersen & Co. Limited | Other services | 2009 |
| Olivia Holdings Ltd | Financial services | 2026 |
| Ondemand Customs Ltd | Wholesale & retail | 2025 |
| Onecare 24 Ltd | Health & social care | 2021 |
| Opimae Landscapes Limited | Administrative & support | 2018 |
| Opsura Consulting Limited | Professional & scientific | 2025 |
| Optima Health & Safety Consultancy Ltd | Professional & scientific | 2014 |
| Opua Ltd | Information & communication | 2019 |
| Orange Spot Solutions Ltd | Professional & scientific | 2017 |
| Orbis Network Limited | Information & communication | 2018 |
| Orca Media Productions Ltd | Professional & scientific | 2023 |
| ORI Kauffmann Ltd | Financial services | 2019 |
| Original Vision Limited | Information & communication | 1983 |
| Orion Schoolwear Limited | Wholesale & retail | 2016 |
| Orion Teamwear Limited | Wholesale & retail | 2016 |
| Orleigh FOX Accounting Limited | Professional & scientific | 2018 |
| Otter Homecare Limited | Health & social care | 2022 |
| OUR Time Project | Health & social care | 2013 |
| Over the Counter Ltd | Wholesale & retail | 2025 |
| Over the Threshold - New Homes Consultancy Ltd | Professional & scientific | 2024 |
| Oversight Consulting Limited | Professional & scientific | 2023 |
| Owlena Ltd | Wholesale & retail | 2025 |
| Oxide Sound Ltd | Information & communication | 2020 |
| OZ Contracting Limited | Information & communication | 2013 |
| P R Comtech Ltd | Professional & scientific | 2000 |
| P&M Pearce Builders Ltd | Manufacturing | 2019 |
| P&T Home Limited | Real estate | 2024 |
| P.B. White (Investments) Limited | Real estate | 1978 |
| PA Collectables Ltd | Wholesale & retail | 2026 |
| PA to Go Ltd | Administrative & support | 2013 |
| Pacific West Foods (UK) Ltd | Wholesale & retail | 2002 |
| Paghalavaan Ltd | Wholesale & retail | 2025 |
| Palaeovision Ltd | Professional & scientific | 2018 |
| Parade House Enterprises Ltd | Arts & recreation | 2022 |
| Parsons Property Development and Management Limited | Real estate | 2025 |
| Partnership Places Ltd | Real estate | 2023 |
| Pass Designs Limited | Information & communication | 2015 |
| Paul Indian Limited | Hospitality | 2026 |
| Paul@Lyons Ltd | Administrative & support | 2018 |
| PBS Warehousing Ltd | Transport & logistics | 2021 |
| PCB Connect Ltd | Manufacturing | 2019 |
| Pcjc Management Ltd | Professional & scientific | 2020 |
| PCS Wilts Limited | Other services | 2014 |
| Peak Sports Limited | Wholesale & retail | 2007 |
| Peake Engineering Services Limited | Manufacturing | 2014 |
| Peake Hydraulic Services Limited | Professional & scientific | 2016 |
| Pebley Beach Limited | Wholesale & retail | 1976 |
| Peculium Automation Ltd | Professional & scientific | 2023 |
| PEL Dynamics Ltd | Professional & scientific | 2024 |
| Peninsula Sand Propco Ltd. | Real estate | 2020 |
| Peopling Ltd | Professional & scientific | 2010 |
| Peppers Hair & Beauty Limited | Other services | 2013 |
| Performa IT Limited | Information & communication | 2011 |
| Performance Ventures Limited | Financial services | 2025 |
| Perpetro Consulting Services Limited | Health & social care | 2006 |
| Perry Landscapes Ltd | Administrative & support | 2018 |
| Petbee Ltd | Wholesale & retail | 2024 |
| Peter Alcock Automotive Limited | Professional & scientific | 2018 |
| Petley House Consulting Limited | Professional & scientific | 2013 |
| Phaedrus Technology Ltd | Professional & scientific | 2020 |
| Phoenix Square Management Company Limited | Households | 2000 |
| Physiojo Limited | Other services | 2019 |
| Pierson Surgical Ltd | Wholesale & retail | 2002 |
| Pike Group Ltd | Construction | 2023 |
| Pink & Co Drinks Ltd | Wholesale & retail | 2019 |
| Pink Grapefruit Media Ltd | Professional & scientific | 2019 |
| Pinky Food Services Ltd | Hospitality | 2023 |
| Pinney's Building Services Ltd | Construction | 2024 |
| Pioneer Technical Services Limited | Professional & scientific | 2018 |
| PIP the Chip Limited | Construction | 2015 |
| Pippett Buildings Limited | Households | 1982 |
| Pistol Juice Limited | Information & communication | 2016 |
| Pjb's Sarap Bites Ltd | Hospitality | 2025 |
| Plain Paper Ltd | Professional & scientific | 2025 |
| Plans, Surveys & Planning Ltd | Professional & scientific | 2021 |
| Plaque OUT Ltd | Wholesale & retail | 2025 |
| Play Space Installations Ltd | Arts & recreation | 2020 |
| Plendering Limited | Real estate | 1978 |
| Plushh Developments Limited | Construction | 2026 |
| Ponte Vechio Ltd | Hospitality | 2018 |
| Positive Presentations Ltd | Professional & scientific | 2022 |
| Positive Press Limited | Information & communication | 2000 |
| Poulsom Design Services Limited | Professional & scientific | 2021 |
| Power Logistics Limited | Administrative & support | 2000 |
| Power Logistics Services Limited | Administrative & support | 2009 |
| Powerkleen Ltd | Administrative & support | 2021 |
| Practech Design Studios Limited | Professional & scientific | 2006 |
| Prajen Ltd | Wholesale & retail | 2026 |
| Precise Decorating Ltd | Construction | 2024 |
| Preemptive Developments 1 Ltd | Real estate | 2025 |