| Noks Hair and Beauty Ltd | Other services | 2024 |
| Nomad Real Estate Group Ltd | Real estate | 2020 |
| North Road Right to Manage Limited | Households | 2026 |
| North West Thundersley Developments Ltd | Construction | 2019 |
| Northville Drive RTM Company Limited | Households | 2007 |
| Notefirst Limited | Hospitality | 2005 |
| Nova Gaming Studios Limited | Information & communication | 2025 |
| NRS Services (Southern) Limited | Health & social care | 2013 |
| Nstechnologies Ltd | Professional & scientific | 2018 |
| Nurse Your Mind Counselling and Psychotherapy Ltd | Health & social care | 2024 |
| Nyame NTI Limited | Administrative & support | 2023 |
| NYC Corporate Ltd | Professional & scientific | 2026 |
| Oakley Trade Services Limited | Information & communication | 2009 |
| Oakwood Palace Trading Limited | Hospitality | 2010 |
| Oasis Interiors Limited | Construction | 2019 |
| Obix Trade Ltd | Water & waste | 2020 |
| Ocean Breeze Cleaning Services Ltd | Administrative & support | 2024 |
| Office 105 Ltd | Real estate | 2022 |
| Ohpal Limited | Financial services | 2016 |
| Olives by the Sea Ltd | Hospitality | 2025 |
| Olivia Gasi Limited | Hospitality | 2018 |
| Omega BLU Ltd | Wholesale & retail | 2020 |
| Omni Strateg Limited | Financial services | 2024 |
| ON the Square Residents Limited | Households | 2004 |
| ON Your Left Management Limited | Professional & scientific | 2019 |
| One W3RLD Limited | Wholesale & retail | 2024 |
| Onesto Services Ltd | Hospitality | 2026 |
| ONJ Construction Management Ltd | Construction | 2024 |
| Only 1 Estates Ltd | Real estate | 2019 |
| Only 2 Estates Ltd | Real estate | 2020 |
| Onryde UK Ltd | Information & communication | 2022 |
| Opal & Rouge Ltd | Other services | 2025 |
| Operation Green Limited | Construction | 2024 |
| Oprimex Ltd | Transport & logistics | 2025 |
| Optical Solutions Limited | Wholesale & retail | 2011 |
| Optimum Financial Contracts Ltd | Financial services | 2018 |
| Opulent SA Ltd | Real estate | 2023 |
| Orangemax Limited | Hospitality | 2019 |
| Organico Cosmetics Ltd | Wholesale & retail | 2026 |
| Oriental Chef (Dagenham) Ltd | Extraterritorial | 2009 |
| Oriental Growth Limited | Hospitality | 2026 |
| Oriental House Restaurant Limited | Hospitality | 2026 |
| Orthis(Uk) Limited | Construction | 2017 |
| OS Search Limited | Administrative & support | 2021 |
| OUR Service Logistics Limited | Transport & logistics | 2025 |
| Overseas Student Education Ltd | Professional & scientific | 2014 |
| OX Audio Ltd | Information & communication | 2020 |
| Oxon Nails Limited | Other services | 2026 |
| Oysterbars Ltd | Hospitality | 2026 |
| P & I Services Limited | Wholesale & retail | 2024 |
| P B Equestrian Services Limited | Education | 2026 |
| P.R. Structural Glazing Limited | Construction | 1999 |
| Pajodab Limited | Construction | 2007 |
| PAK UK Food Ltd. | Hospitality | 2017 |
| Palacourt Limited | Hospitality | 1987 |
| PAN Asian Plaza Management Limited | Hospitality | 2025 |
| Pane E Vino Restaurant Limited | Hospitality | 2020 |
| PAO MEN Hotpot Limited | Hospitality | 2024 |
| Papa Mama D Ltd | Real estate | 2026 |
| Paperback Designs Limited | Information & communication | 2012 |
| Paragon Training and Consulting Limited | Construction | 2016 |
| Parallel Processing Limited | Information & communication | 2003 |
| Parcelwings Ltd | Transport & logistics | 2023 |
| Paribus Investments Limited | Financial services | 2017 |
| Park Island Limited | Hospitality | 2026 |
| Park Road Estates Ltd | Real estate | 2021 |
| Parkside Development Company Limited | Construction | 1990 |
| Partridge Estate Limited | Real estate | 2024 |
| PAT Nkwonta Limited | Health & social care | 2013 |
| Patin Limited | Other services | 2014 |
| Paul Robinson Solicitors LLP | | 2001 |
| Pavilion Newsagent Ltd | Wholesale & retail | 2023 |
| Paving the Way Groundworks and Building Services Limited | Construction | 2026 |
| PBC Security Ltd | Administrative & support | 2022 |
| Peachdrop Limited | Hospitality | 2020 |
| Pennington & Pennington Limited | Wholesale & retail | 2020 |
| Pennington and Partners Limited | Administrative & support | 2010 |
| Pentview Estates Ltd | Real estate | 2020 |
| Peppino's Catering Ltd | Manufacturing | 2021 |
| Perfect Imaging Ltd | Professional & scientific | 2015 |
| Pershore Estates Limited | Real estate | 2026 |
| Pharma Solutions Ltd | Professional & scientific | 2025 |
| Pharmbear Limited | Health & social care | 2025 |
| Piano Pavilion (Brentwood) Limited | Wholesale & retail | 2003 |
| Picchio Limited | Hospitality | 2012 |
| Pineacre Developments Limited | Real estate | 1996 |
| Pinky Nails Ltd | Other services | 2024 |
| Pinkybell Limited | Hospitality | 2019 |
| Pinnacle Haven Estates Limited | Real estate | 2025 |
| Pint & Pitcher Limited | Hospitality | 2025 |
| Pipe Tech Line Limited | Water & waste | 2023 |
| Pitsa UK Ltd | Wholesale & retail | 2023 |
| Pivotal Productions Community Interest Company | Arts & recreation | 2023 |
| Pizza Smash Ltd | Hospitality | 2025 |
| Pizza Station London Ltd | Hospitality | 2024 |
| Piñatas México UK - Pinatas Mexico UK Ltd | Wholesale & retail | 2022 |
| PJS Aviation Limited | Other services | 2017 |
| Pladden Limited | Hospitality | 2019 |
| Plas SOS Ltd | Manufacturing | 2024 |
| PLN Property Maintenance Ltd | Construction | 2018 |