| OMA Properties Ltd | Real estate | 2018 |
| Omniabooks Ltd | Wholesale & retail | 2021 |
| Omsai Developers Limited | Real estate | 2021 |
| ON Investments Ltd | Financial services | 2021 |
| On-Line Publishing Ltd | Wholesale & retail | 2020 |
| ONA Sports Investment Limited | Arts & recreation | 2021 |
| One Day Group Ltd | Information & communication | 2020 |
| One Email Away Ltd | Wholesale & retail | 2024 |
| One Music Studio Ltd | Information & communication | 2026 |
| One Point Finance Ltd | Professional & scientific | 2025 |
| Onel Cleaning Ltd | Administrative & support | 2023 |
| Online Support Computing Limited | Information & communication | 1997 |
| Ons-Novotech Ltd | Wholesale & retail | 2023 |
| Onyx Connections Limited | Information & communication | 2010 |
| Open a European Company Limited | Professional & scientific | 2003 |
| Openaukcompany.Com Limited | Professional & scientific | 2007 |
| Opia Collective Ltd | Arts & recreation | 2018 |
| Optifinance Bookkeeping Services Ltd | Professional & scientific | 2024 |
| Opulent Investments Ltd | Real estate | 2014 |
| Opulent Property Portfolio Ltd | Real estate | 2017 |
| OR & Wonder Interiors Ltd | Wholesale & retail | 2014 |
| OR & Wonder Ltd | Wholesale & retail | 2014 |
| Orange Hill Studio Ltd | Information & communication | 2022 |
| Orbital Aluminium Industries Ltd. | Other services | 2020 |
| Organisation Mvuala Motoko Alidor Ltd | Agriculture & fishing | 2018 |
| Orion Square Limited | Real estate | 2026 |
| ORM Accounting Services Limited | Professional & scientific | 2011 |
| Orso Practice Ltd | Health & social care | 2015 |
| OSI Chocolate Ltd | Wholesale & retail | 2026 |
| Osier Group Limited | Professional & scientific | 2017 |
| Osterley Education Limited | Education | 2021 |
| OTK Property Ltd | Real estate | 2020 |
| Otkie Solutions Ltd | Information & communication | 2019 |
| Ourbarn at Blondin CIC | Health & social care | 2026 |
| Outer Edge Investments Limited | Real estate | 2000 |
| Outperform Ltd | Education | 2023 |
| Outronix Ltd | Wholesale & retail | 2025 |
| Outset Productions Limited | Information & communication | 2025 |
| Oxyn AI Ltd | Information & communication | 2026 |
| Ozmam Productions Ltd | Information & communication | 2018 |
| Ozon International LLP | | 2020 |
| P SEN Healthcare Limited | Health & social care | 2024 |
| P&A Joinery Solutions Ltd | Construction | 2016 |
| P. Goddard & Sons Limited | Wholesale & retail | 1947 |
| P5EM5VATH5 Ltd | Education | 2025 |
| PA 2 Assist Ltd | Administrative & support | 2023 |
| Pablo Creation Global Ltd | Wholesale & retail | 2023 |
| Paddys Paws Ealing Ltd | Agriculture & fishing | 2023 |
| Padria Ltd | Wholesale & retail | 2018 |
| Pageone Communications Limited | Information & communication | 2002 |
| Pagiola Ltd | Professional & scientific | 2026 |
| Palani Sound Ltd | Information & communication | 2026 |
| Pals Spirits UK Ltd | Administrative & support | 2023 |
| PAM Wharfe Consulting Ltd | Professional & scientific | 2015 |
| Pambino Ltd | Professional & scientific | 2026 |
| Paneandpasta Ltd | Hospitality | 2025 |
| Pangea Konsulting Limited | Information & communication | 2023 |
| Pansy Applications Limited | Information & communication | 2018 |
| Panta Rhei Ventures Ltd | Wholesale & retail | 2021 |
| Paper Adventures Limited | Arts & recreation | 2022 |
| PAR Essentials Limited | Wholesale & retail | 2024 |
| Paradise Residences Ltd | Hospitality | 2014 |
| Paragon Digital Limited | Professional & scientific | 2015 |
| Paramount London Ltd | Wholesale & retail | 2018 |
| Park & Go Ltd | Transport & logistics | 2025 |
| Park Farm Properties Ltd | Real estate | 2018 |
| Parthenia Advisory Ltd | Professional & scientific | 2025 |
| Particles Ltd | Administrative & support | 2016 |
| Partisan Ltd | Manufacturing | 2006 |
| Partspoint Ltd | Wholesale & retail | 2023 |
| Partum Life Sciences Ltd | Administrative & support | 2022 |
| Pasinet Limited | Information & communication | 2011 |
| Passione VG Ltd | Wholesale & retail | 2019 |
| Pathology Labs Ltd | Professional & scientific | 2020 |
| Patient - Practitioner Partnership Limited | Professional & scientific | 2010 |
| Patisserie Conseil Limited | Manufacturing | 2014 |
| Patisserie LES 3 Chocolats Ltd | Hospitality | 2018 |
| Patrick Harrigan Ltd | Other services | 2008 |
| Paul's Bakers (Southall) Limited | Wholesale & retail | 2000 |
| Payfuture Holdings Limited | Financial services | 2022 |
| Paymai Properties Limited | Real estate | 2024 |
| PB Customs Agency Ltd | Extraterritorial | 2021 |
| PBA Painting & Decorating Ltd | Construction | 2025 |
| PBC Investment Ltd | Real estate | 2022 |
| PCL Enterprises Limited | Education | 2005 |
| PDD Construction Ltd | Construction | 2018 |
| PDR Medical Ltd | Health & social care | 2016 |
| Peacock Cottage Breaks Limited | Real estate | 2014 |
| Peak Engineering Ltd | Professional & scientific | 2022 |
| Pearl Accountants Limited | Professional & scientific | 2009 |
| Pearlsap Private Limited | Information & communication | 2014 |
| Pearson DJA Holdings Limited | Financial services | 2025 |
| Penmar Care Ltd | Health & social care | 2018 |
| People Power Limited | Energy | 2019 |
| People Watching Pictures Ltd | Information & communication | 2023 |
| Peopro Limited | Professional & scientific | 2020 |
| Perfect Served Limited | Professional & scientific | 2023 |
| Perissology Group Ltd | Wholesale & retail | 2017 |
| Perks Plus Ltd | Other services | 2023 |
| Persian Artisan Rugs Ltd | Wholesale & retail | 2025 |