| Nauseda Trans Ltd | Transport & logistics | 2016 |
| Navan Capital Limited | Professional & scientific | 2024 |
| Nbye Ltd | Hospitality | 2025 |
| NEB Lane Residents Association Limited | Households | 2000 |
| Nelatox Ltd | Construction | 2025 |
| Netkandy Limited | Information & communication | 2022 |
| Netprovision Ltd | Professional & scientific | 2002 |
| New Ground Churches | Other services | 2007 |
| Newlands (Wimbledon) Management Ltd | Real estate | 2025 |
| Newshield Enterprises Limited | Manufacturing | 1993 |
| Newstech Limited | Information & communication | 1995 |
| Newtons Tree Services Limited | Agriculture & fishing | 2024 |
| Next Step Developments Limited | Real estate | 2010 |
| Next Step Developments PH Ltd | Real estate | 2017 |
| Next Step Nursing Limited | Hospitality | 2017 |
| Next Step Pathways Limited | Hospitality | 2017 |
| Next Step Removals Limited | Transport & logistics | 2024 |
| Nextprime Charters Limited | Administrative & support | 2016 |
| Nextprime Limited | Construction | 2017 |
| NIC Consultancy Limited | Professional & scientific | 2013 |
| Nicholas Emmins Consulting Limited | Financial services | 2018 |
| Nick Auer Consulting Ltd | Professional & scientific | 2022 |
| Nick Cook Audio Ltd | Information & communication | 2013 |
| Nick Elias Architects Ltd | Professional & scientific | 2021 |
| Nigel Mawer Limited | Other services | 2014 |
| Njjl Consulting Ltd | Wholesale & retail | 2026 |
| Noetic Management Ltd | Administrative & support | 2024 |
| Noko Space Ltd | Real estate | 2020 |
| Nomalux Ltd | Real estate | 2019 |
| North Central Developments Limited | Construction | 1992 |
| Northgate Asset Property Ltd | Real estate | 2025 |
| Northgate Corporate Holdings Ltd | Other services | 2025 |
| Northgate Hospitality Ltd | Hospitality | 2025 |
| Northgate M&E Ltd | Construction | 2025 |
| Northstand Limited | Information & communication | 2006 |
| Northwind CAD Limited | Professional & scientific | 2012 |
| Noseum Editions Ltd | Wholesale & retail | 2024 |
| Notting Hill Artisan Bakery Ltd | Manufacturing | 2026 |
| NSD Holdings Limited | Construction | 2023 |
| NSG Rail Limited | Construction | 2019 |
| Nuactiv Ltd | Wholesale & retail | 2018 |
| Nutfield Motor Repairs Limited | Wholesale & retail | 2020 |
| Nutrasource Ltd | Wholesale & retail | 2020 |
| OA LDN Ltd | Wholesale & retail | 2025 |
| Oakley & Glaser Limited | Administrative & support | 2017 |
| Oakstyle Limited | Real estate | 2024 |
| Octave Intermediaries Limited | Professional & scientific | 2015 |
| Office Solutions (S E) Limited | Administrative & support | 2007 |
| OJW Creative Services Ltd | Professional & scientific | 2020 |
| Old Elthamians Association Limited | Other services | 2012 |
| Oldtownbuilders Limited | Construction | 2023 |
| Olivia Ebba Aesthetics Ltd | Health & social care | 2024 |
| Omnis Glazing Ltd | Construction | 2019 |
| One Life Cycle Ltd | Arts & recreation | 2024 |
| Onvision Limited | Wholesale & retail | 1999 |
| Oparo Social ST James Ltd | Real estate | 2024 |
| Opas (Southern) Limited | Wholesale & retail | 1984 |
| Openfire Consulting Ltd | Professional & scientific | 2011 |
| Opus Cleaning Limited | Administrative & support | 2014 |
| Orange Health Partners Ltd | Health & social care | 2025 |
| Orbital Tech Solutions Limited | Construction | 2023 |
| Ottoman Restaurants BR Ltd | Hospitality | 2024 |
| Ottoman WW Ltd | Hospitality | 2024 |
| Outdoor Services Limited | Administrative & support | 2000 |
| Oxted EYE Clinic Ltd | Other services | 2016 |
| Oxted Fertility Services Ltd | Health & social care | 2020 |
| Oxted House Ltd | Hospitality | 2021 |
| Oxted Mushrooms Limited | Agriculture & fishing | 2024 |
| Oxted Peri Peri Limited | Hospitality | 2025 |
| P D Motors (Croydon) Limited | Wholesale & retail | 2003 |
| P.K. Slack Limited | Construction | 2012 |
| P2 Consulting Ltd | Information & communication | 2024 |
| P4R Securities Limited | Financial services | 2012 |
| Pabbi Properties Limited | Real estate | 2017 |
| Pack UP Removals Ltd | Transport & logistics | 2024 |
| Padbrook Imaging Limited | Professional & scientific | 2011 |
| Pally Services Limited | Administrative & support | 2006 |
| Pampa Massage and Beauty Ltd | Health & social care | 2023 |
| Pandamilk Ltd | Professional & scientific | 2020 |
| Panini on the Park Ltd | Hospitality | 2021 |
| Paparazzle Limited | Extraterritorial | 2011 |
| Papillon Catering Limited | Professional & scientific | 2009 |
| Paradigm 24 Limited | Administrative & support | 2024 |
| Park Farm (Bluehouse) Limited | Extraterritorial | 2015 |
| Park Giant UK Ltd | Transport & logistics | 2020 |
| Park Mews Limpsfield Limited | Extraterritorial | 2010 |
| Parkmore Healthcare Ltd | Health & social care | 2004 |
| Parsons Croft Chapmans Limited | Construction | 2021 |
| Party Pack Builder Ltd | Wholesale & retail | 2025 |
| Patristan Ltd. | Wholesale & retail | 2011 |
| Payne & Co Limited | Real estate | 2011 |
| Pcos UK Limited | Health & social care | 2005 |
| PD Documentaries Ltd | Wholesale & retail | 2021 |
| PDB9 Ltd | Information & communication | 2016 |
| PDS People LLP | | 2015 |
| Penlee Point Management Limited | Administrative & support | 2015 |
| Penrhiw Group Ltd | Professional & scientific | 2025 |
| Penrice Jones Ltd | Other services | 2023 |
| Pepperstreet Designs Limited | Professional & scientific | 2025 |
| Percipio Consulting Ltd | Information & communication | 2022 |