| Oxford Primary & College Limited | Education | 2016 |
| Oxford R Z Ltd | Wholesale & retail | 2022 |
| Oxford Street Luggage Wholesale Ltd | Wholesale & retail | 2023 |
| Oxlip Learning Partnership | Education | 2011 |
| Oxtavelum Ltd | Information & communication | 2021 |
| OXY Interiors Ltd | Construction | 2023 |
| Oxygen Mind Limited | Administrative & support | 2018 |
| Oymyakon Holdings Limited | Financial services | 2025 |
| Oyster Properties Limited | Construction | 2006 |
| Oysterworld Sailing Holidays Limited | | 1981 |
| Ozarda Ltd | Other services | 2011 |
| Ozbek & SON Ltd | Real estate | 2024 |
| Ozzy&Anays Trans Ltd | Transport & logistics | 2023 |
| P & G Stores Ltd | Wholesale & retail | 2025 |
| P & O Builders Limited | Extraterritorial | 1997 |
| P & O Ferrymasters Holdings Limited | Professional & scientific | 2002 |
| P & P Blast Cleaning Limited | Administrative & support | 2016 |
| P & P Building Services (East Anglia) Ltd | Construction | 2014 |
| P & P Haulage and Handling Limited | Transport & logistics | 2008 |
| P & R Corporation Limited | Financial services | 2023 |
| P a COX Trading Limited | Administrative & support | 2015 |
| P a Hambling Limited | Construction | 2005 |
| P B Carpentry & Building Services Ltd. | Construction | 2018 |
| P Bhagwat Limited | Health & social care | 2019 |
| P C Rust Builders Limited | Construction | 2026 |
| P C S Limited | Real estate | 1995 |
| P Douglas Finance Limited | Professional & scientific | 2011 |
| P Freeman Horticulture Ltd | Other services | 2023 |
| P H Pumps Ltd | Manufacturing | 2005 |
| P J M Farms (Holdings) Limited | Professional & scientific | 2011 |
| P J M Farms Limited | Agriculture & fishing | 2010 |
| P J Reed Limited | Transport & logistics | 2014 |
| P J Smith Roofing Limited | Construction | 1999 |
| P R Davey Engineering Limited | Professional & scientific | 2002 |
| P R Hodgson Limited | Other services | 2002 |
| P R Roast & Company Limited | Manufacturing | 1964 |
| P&D Build Limited | Construction | 2024 |
| P&H Estates (Suffolk) Ltd | Real estate | 2023 |
| P&P Europe Ltd | Information & communication | 2023 |
| P'S Punch Ltd | Wholesale & retail | 2026 |
| P. & V. Inns Limited | Real estate | 2015 |
| P. G. Laundry Services Ltd | Other services | 2013 |
| P. KAY (Ipswich) Limited | Transport & logistics | 1967 |
| P. Witcher Courier Services Limited | Transport & logistics | 2009 |
| P.J.Shone(Colchester)Limited | | 1960 |
| P.M.C. Landscapes Limited | Other services | 2000 |
| P.R. & R.H. Leggett Limited | Agriculture & fishing | 1999 |
| P.S. Partridge Limited | Agriculture & fishing | 1959 |
| P11@HOME Limited | Administrative & support | 2015 |
| P2 Enterprises Limited | Real estate | 2018 |
| PA Manufacturing Ltd | Manufacturing | 2025 |
| Paap Ltd | Professional & scientific | 2025 |
| Paat Travel Solution Limited | Transport & logistics | 2026 |
| Pachihera Estates Ltd | Real estate | 2022 |
| Pachihera Store Ltd | Wholesale & retail | 2020 |
| Pacific Fish and Meat Ltd | Wholesale & retail | 2024 |
| Pacific Super Stores Ltd | Wholesale & retail | 2026 |
| Packmate Ltd | Transport & logistics | 2025 |
| Packo’S Service & Repairs Ltd | Wholesale & retail | 2024 |
| Pacp Ltd | Information & communication | 2017 |
| Pacs Investments Ltd | Real estate | 2021 |
| Paddy and Scotts Cafes Ltd | Wholesale & retail | 2007 |
| Paddy Solutions Limited | Administrative & support | 2023 |
| Padel Ipswich Limited | Arts & recreation | 2024 |
| Padel Utopia Limited | Other services | 2023 |
| Padel Worx Ltd | Arts & recreation | 2025 |
| Padel XO Ltd | Arts & recreation | 2018 |
| Padrino Limited | Households | 2008 |
| Padsmile Limited | Health & social care | 2018 |
| PAF Project Management Services Limited | Construction | 2019 |
| Pago Pro Ltd | Professional & scientific | 2022 |
| Paint and Paper Limited | Wholesale & retail | 1995 |
| Paint Protection Film Centre Ltd | Wholesale & retail | 2020 |
| Painting and Decorating/Cleaning Ltd | Administrative & support | 2024 |
| PAJ Investment Properties Limited | Real estate | 2017 |
| Pajoma 139 Limited | Real estate | 2015 |
| Pajoma Limited | Real estate | 2014 |
| Pakenham Sporting Ltd | Arts & recreation | 2010 |
| Pakryse Ltd | Other services | 2024 |
| Palfost Property Developments Limited | Construction | 2023 |
| Palheirapt Limited | Transport & logistics | 2023 |
| Palladio Construction Ltd | Construction | 2025 |
| Palladio Homes Ltd | Construction | 2025 |
| Palladium Distribution Limited | Wholesale & retail | 1995 |
| Pallippatt TM Ltd | Construction | 2022 |
| Palmerston Court Management Company (2005) Limited | Real estate | 2004 |
| PAM Foreman Occupational Therapy Services Limited | Health & social care | 2023 |
| Pamssl Ltd | Wholesale & retail | 2019 |
| PAN African Calabash Media Ltd | Information & communication | 2026 |
| PAN Property Services Ltd | Real estate | 2025 |
| PANAS4 Ltd | Transport & logistics | 2026 |
| Pandoro Limited | Transport & logistics | 1947 |
| Panna Properties Limited | Real estate | 2019 |
| Pannington Hall Cottage Holiday Lets Ltd | Hospitality | 2022 |
| Panopco Ltd | Administrative & support | 2025 |
| Papa Piri Piri UK Ltd | Other services | 2020 |
| Papaky Coffee Shop (Ipswich ) Ltd | Hospitality | 2025 |
| Papaky Coffee Shop Limited | Hospitality | 2019 |
| Papyto Ltd | Transport & logistics | 2025 |
| Paradigm Sports Intelligence Ltd | Information & communication | 2023 |