| Oluyinkasho Limited | Professional & scientific | 2024 |
| OMA Education Limited | Administrative & support | 2025 |
| Omega Network Solutions Limited | Information & communication | 2009 |
| Omemma Enterprises Ltd | Wholesale & retail | 2023 |
| Omjaj Ltd | Wholesale & retail | 2025 |
| Omnibuild Ltd | Construction | 2025 |
| Omosa Limited | Construction | 2025 |
| Omra Consulting Limited | Professional & scientific | 2009 |
| ON Call Plumber Ltd | Construction | 2021 |
| Onboarding Pro Consultancy Limited | Professional & scientific | 2025 |
| One Emmanuel Limited | Construction | 2015 |
| One World Agents Limited | Information & communication | 2012 |
| Onwards & Upwards Training Ltd | Education | 2020 |
| Onwards and Training Limited | Education | 2022 |
| Optimum Cleans Ltd | Administrative & support | 2026 |
| Optyc Electrical Solutions Limited | Construction | 2026 |
| Opulence Solutions Technologies Ltd | Information & communication | 2013 |
| OPX Peer Systems Ltd | Information & communication | 2026 |
| Opyjay Ltd | Professional & scientific | 2023 |
| Orange Performing Arts Ltd | Health & social care | 2023 |
| Orchid Citi Ltd | Extraterritorial | 2020 |
| Oregon Transit Logistik GmbH Ltd | Transport & logistics | 2023 |
| Organic Super Foods Ltd | Wholesale & retail | 2025 |
| Orion Access (Equipment) Limited | Administrative & support | 2009 |
| Orion Access Hire and Training Ltd | Administrative & support | 2017 |
| Orion Access Platforms Ltd | Administrative & support | 2017 |
| Orion Access Training Ltd | Administrative & support | 2017 |
| Orion Services (UK) Limited | Administrative & support | 1998 |
| Orlando Entertainment Limited | Arts & recreation | 2017 |
| Orleeman Financial Services Limited | Financial services | 2016 |
| Orleeman Property Solutions Limited | Real estate | 2016 |
| Osahon Cleaning Ltd | Administrative & support | 2025 |
| Osarum Properties Limited | Real estate | 2024 |
| Oscar and Henley Rail Solutions Ltd | Construction | 2017 |
| Osimen Rail Services Limited | Construction | 2012 |
| Osiris Mart UK Limited | Wholesale & retail | 2022 |
| Osman Sesay Services Ltd | Construction | 2014 |
| Otisbounty Courier Services Limited | Transport & logistics | 2019 |
| Ottoman Grill Limited | Hospitality | 2019 |
| OTU Services Ltd | Administrative & support | 2026 |
| Outfit Management Limited | Construction | 2019 |
| Overlay Services Ltd | Information & communication | 2011 |
| Ovotino Media Ltd | Information & communication | 2015 |
| Owen Support Services Limited | Health & social care | 2013 |
| Own IT! Enterprise Company Limited | Real estate | 2024 |
| Owoyale Ltd | Hospitality | 2024 |
| OX Tea Limited | Manufacturing | 2017 |
| Ozeks Limited | Health & social care | 2023 |
| P & B Mechanical Services Limited | Construction | 2003 |
| P Chalk Holdings Ltd | Administrative & support | 2017 |
| P J Property & Maintenance Ltd | Real estate | 2016 |
| P&Pexclusive Ltd | Wholesale & retail | 2020 |
| P&V General Business Ltd | Wholesale & retail | 2016 |
| P. Chalk Limited | Administrative & support | 1995 |
| P.G.L. Electrical Services Limited | Wholesale & retail | 1985 |
| P.R.M Lift Services Ltd | Professional & scientific | 2025 |
| PAA Plus 1 Ltd | Public administration | 2019 |
| Pabidok Ventures UK Limited | Health & social care | 2014 |
| Paintedbychristelle Ltd | Other services | 2021 |
| Pakt London Limited | Manufacturing | 2010 |
| Pamy Building Services Ltd | Construction | 2023 |
| Panda Plus Care Services Ltd | Health & social care | 2022 |
| Pangea Express Logistics Ltd | Transport & logistics | 2025 |
| Papcloud Limited | Information & communication | 2015 |
| Parcelmate Logistics Limited | Transport & logistics | 2016 |
| Parent Power Education Limited | Education | 2019 |
| Pashabuild Ltd | Construction | 2018 |
| PAT Tarrant Floats | | 1998 |
| Path to Progress Consultancy Ltd | Education | 2025 |
| Pathkind Ltd | Administrative & support | 2025 |
| Paths Publishing Group Ltd. | Information & communication | 2011 |
| Patricgaalmi Limited | Wholesale & retail | 2025 |
| Patspiration Club CIC | Professional & scientific | 2026 |
| Pattycare Walls Limited | Health & social care | 2024 |
| Pavcon Events Ltd | Administrative & support | 2025 |
| Pawpaw Tree Ltd | Wholesale & retail | 2024 |
| Payment Hub Limited | Administrative & support | 2024 |
| PC Strategic Consulting Limited | Professional & scientific | 2014 |
| PCL Transport SVS Ltd | Wholesale & retail | 2021 |
| PE Signature Properties Ltd | Real estate | 2021 |
| Peace & Passion Care Service Limited | Health & social care | 2026 |
| Peace Childminder Ltd | Health & social care | 2025 |
| Peace Manor Residential Care Limited | Health & social care | 2011 |
| Peak Rock Ltd | Wholesale & retail | 2003 |
| Pearleview Limited | Real estate | 2021 |
| Pearone Financial Solutions Ltd | Financial services | 2015 |
| Peculiar Care Homes Limited | Health & social care | 2013 |
| Pekulia Productions Ltd | Hospitality | 2024 |
| Pembury Clarke Accountants Ltd | Professional & scientific | 2020 |
| Pemogrand Ltd | Professional & scientific | 2018 |
| Peniel Care Support Services Ltd | Health & social care | 2025 |
| Peniel International Limited | Health & social care | 2003 |
| Peniel Properties Limited | Real estate | 2022 |
| People Centric Solutions Limited | Administrative & support | 2023 |
| Perennity Bridge Ltd | Information & communication | 2026 |
| Perfect Facilities Services Ltd | Administrative & support | 2013 |
| Petaiye Ltd | Real estate | 2025 |
| Petar Mitov Ltd | Construction | 2024 |
| Petezems Ltd | Health & social care | 2024 |
| Petnor Media Solutions Limited | Professional & scientific | 2020 |