| Newschools (Merton) Limited | Administrative & support | 2002 |
| Newschools (Swanscombe) Holdings Limited | Administrative & support | 2001 |
| Newschools (Swanscombe) Limited | Administrative & support | 2001 |
| Nexgen Solutions Ltd | Wholesale & retail | 2022 |
| Next Door Hextable C.I.C. | Hospitality | 2022 |
| Next GEN Development and Lettings Limited | Real estate | 2022 |
| NGS Kent Limited | Construction | 2025 |
| Nigel Endersby Advertising & Marketing Limited | Professional & scientific | 2002 |
| Nines MEN Limited | Construction | 2015 |
| Nivaria Capital Ltd | Financial services | 2024 |
| NLG Investment Group Limited | Financial services | 2023 |
| NMH Services Ltd | Construction | 2026 |
| NO Letting Go Inventory Management Ltd | Administrative & support | 2007 |
| Noblehorizons Crest Ltd | Information & communication | 2023 |
| NON Nocere Health Ltd | Health & social care | 2025 |
| Nora Financial Ltd | Financial services | 2025 |
| Nordic House Ltd | Hospitality | 2024 |
| North Halling Engineering Ltd | Water & waste | 2005 |
| North Halling Holdings Limited | Financial services | 2022 |
| Nter Estates Ltd | Other services | 2020 |
| Nurtura Care Group Ltd | Administrative & support | 2025 |
| Nutramare UK Ltd | Wholesale & retail | 2026 |
| NZR Windows & Doors Limited | Construction | 2000 |
| O and PM Ltd | Professional & scientific | 2018 |
| O&H Property Limited | Real estate | 2022 |
| O'Moore Limited | Wholesale & retail | 2014 |
| Oakfield Flat Roofing Limited | Construction | 2011 |
| Oaklands Treesurgeons & Landscape Gardeners Limited | Administrative & support | 2005 |
| Oakline Property Solutions Ltd | Administrative & support | 2025 |
| Oakview Place Maintenance Limited | Households | 2024 |
| Oakwoods Joinery Limited | Construction | 1977 |
| Ocimum Consulting Limited | Information & communication | 2010 |
| OES Technology Ltd | Information & communication | 2016 |
| OH Plumbing Ltd | Construction | 2022 |
| OJC Heating Limited | Construction | 2020 |
| OKR Holdings Limited | Financial services | 2019 |
| Okunnuga Solid Mineral Exchange Limited | Administrative & support | 2025 |
| Olaru Properties Ltd | Real estate | 2026 |
| OLH Holdings Limited | Financial services | 2023 |
| Omez Services Ltd | Administrative & support | 2017 |
| Onalis Quality Solutions Ltd | Professional & scientific | 2019 |
| Onboard Interiors Ltd | Construction | 2019 |
| One City Maintenance Limited | Construction | 2012 |
| Operationx Limited | Information & communication | 2025 |
| Optimum Autos Limited | Wholesale & retail | 2026 |
| Opulent Bespoke Limited | Construction | 2022 |
| Orbmix Technologies Ltd | Information & communication | 2023 |
| Orca Search Ltd | Administrative & support | 2012 |
| Orion Trade Supplies Limited | Wholesale & retail | 2014 |
| OS South East Group Limited | Construction | 2025 |
| Osage Dynasty Properties Management LLP | | 2024 |
| Osage Limited | Information & communication | 2008 |
| Osage Properties Limited | Real estate | 2018 |
| Osra Consulting Limited | Information & communication | 2011 |
| OSW Co Holdings 1 Limited | Financial services | 2016 |
| OSW Co Holdings 2 Limited | Financial services | 2016 |
| OSW Co Holdings 3 Limited | Financial services | 2019 |
| OSW Co Investments Limited | Financial services | 2019 |
| OSW LP Holdco Limited | Financial services | 2016 |
| Ottaway & Thompson Group Limited | Construction | 2025 |
| Owner.Ly Ltd | Real estate | 2020 |
| Ozilo Auto Limited | Manufacturing | 2025 |
| Ozsez Ltd | Real estate | 2026 |
| P & J Home Improvements Limited | Construction | 2016 |
| P C Doyle Construction Limited | Construction | 1997 |
| P J Steel Limited | Wholesale & retail | 2003 |
| P Patel Consulting Limited | Information & communication | 2026 |
| P W Lifting Limited | Construction | 2017 |
| P White Flooring Limited | Construction | 2012 |
| P&P Logistics Ltd | Transport & logistics | 2021 |
| P&Z Solutions Limited | Wholesale & retail | 2018 |
| PA Tree and Garden Care Ltd | Agriculture & fishing | 2021 |
| Padel Primero Ltd | Wholesale & retail | 2025 |
| Padris Real Estate UK Limited | Real estate | 2017 |
| Padwer Property Limited | Construction | 2022 |
| Page Garden Services Limited | Administrative & support | 2024 |
| PAN Care Service Ltd | Health & social care | 2018 |
| Panda Technical Services Limited | Information & communication | 2010 |
| Panter Roofing Limited | Construction | 2025 |
| Paragon Enforcement Ltd | Administrative & support | 2020 |
| Parallel Mechanical Services Limited | Construction | 2026 |
| Paranishma Limited | Professional & scientific | 2020 |
| Parcock Computing Limited | Information & communication | 2016 |
| Parisse Care Consulting Limited | Health & social care | 2014 |
| Park Home Projects Ltd | Administrative & support | 2025 |
| Parkwood Hall Co-Operative Academy Trust | Education | 2015 |
| Parkwood Hall School Voluntary Fund | Education | 2011 |
| Partner Construction Limited | Construction | 2010 |
| Partner Contracting Limited | Construction | 1998 |
| Partner Group U.K. Limited | Real estate | 2011 |
| Partner Investments Limited | Real estate | 2013 |
| Party Vibe Tribe Ltd | Other services | 2025 |
| Passion DU Fromage Ltd | Wholesale & retail | 2010 |
| Patch and MIX Crafts Limited | Wholesale & retail | 2020 |
| Paul Wilson Services Limited | Health & social care | 2009 |
| PDC Sevenoaks Limited | Health & social care | 2020 |
| PDE Solutions Ltd | Construction | 2023 |
| PDL Ductwork Limited | Construction | 2017 |
| Peaches Hair and Beauty Limited | Other services | 2024 |
| Peakline Access Group Limited | Construction | 2026 |