| Merry MEN Pizza Company Ltd | Hospitality | 2025 |
| MF Recruitment Limited | Administrative & support | 2017 |
| Miramo Ltd | Information & communication | 2025 |
| Moles Farm Stables Ltd | Agriculture & fishing | 2026 |
| Monopoly Developments Limited | Construction | 2025 |
| Monopoly PEF Limited | Financial services | 2025 |
| Move 2 Cloud Solutions Limited | Information & communication | 2018 |
| Movewright Limited | Other services | 2024 |
| MRA Developments Limited | Construction | 2025 |
| Multicut Precision Engineering Ltd | Professional & scientific | 2024 |
| Multiversal Media Limited | Manufacturing | 2024 |
| MVP Plumbing and Heating Ltd | Construction | 2015 |
| My Lucky Penny Ltd | Wholesale & retail | 2018 |
| My Rental Properties Limited | Real estate | 2024 |
| N M Publishing Services Limited | Information & communication | 2011 |
| Nagcabs Ltd | Transport & logistics | 2013 |
| National Womens Register | Other services | 1986 |
| Nationwide Fire Risk Assessments Limited | Professional & scientific | 2017 |
| Nationwide Supplies Buntingford Limited | Wholesale & retail | 2010 |
| Navig Holdings Limited | Real estate | 1970 |
| NB Skip Hire Ltd | Construction | 2022 |
| Nemetech Ltd | Wholesale & retail | 2024 |
| Nest Innovations Limited | Wholesale & retail | 2025 |
| Newbold Property Investments Limited | Real estate | 2004 |
| Nextgenplaymakers Ltd | Education | 2024 |
| Niehorster Property Group Limited | Households | 2025 |
| NJE Cleaning Services Limited | Administrative & support | 2018 |
| NJE Residential Cleaning Services Limited | Administrative & support | 2018 |
| Norcon Software Limited | Information & communication | 2013 |
| Norfolk AD Holding Limited | Energy | 2021 |
| Norfolk Road Ltd | Health & social care | 2021 |
| Nowtax Ltd | Professional & scientific | 2025 |
| NPR & V3 Consultants Ltd | Information & communication | 2013 |
| NPR & V3 Properties Ltd | Real estate | 2020 |
| NSN Motors Ltd | Wholesale & retail | 2020 |
| Oakleys Pet Shop Ltd | Wholesale & retail | 2026 |
| Oasis 2 Inclusion Academy Limited | Health & social care | 2014 |
| Old Etonian Trust(The) | Health & social care | 1940 |
| One Company Heating Limited | Construction | 2022 |
| One for the Road Rentals Ltd | Wholesale & retail | 2024 |
| Onez Consults Ltd | Professional & scientific | 2020 |
| Online Piano Feedback Service Limited | Education | 2024 |
| Optimum Property Portfolio Ltd | Real estate | 2025 |
| Orbital Travel Limited | Administrative & support | 2001 |
| Orire Management Ltd | Information & communication | 2021 |
| Osborne Recruitment Solutions Ltd | Administrative & support | 2026 |
| Owlet Farm Ltd | Real estate | 2018 |
| P More Developments Limited | Financial services | 2020 |
| P.R. Newson Ltd | Agriculture & fishing | 2003 |
| PAK Bangla Venture Ltd | Wholesale & retail | 2026 |
| Pandora Technology Limited | Extraterritorial | 2014 |
| Park 'N' Load Metal Recycling Limited | Water & waste | 2011 |
| Patient END Barns Management Company Limited | Other services | 2001 |
| Patrick Photographer Limited | Professional & scientific | 2005 |
| Paul D White Limited | Extraterritorial | 2012 |
| Paul F Ingram Limited | Manufacturing | 2011 |
| Paul Hewett Design Ltd | Professional & scientific | 2021 |
| Paul Wordley LLP | | 2019 |
| PBT Enterprises Ltd | Professional & scientific | 2008 |
| Peach Property Holdings Limited | Real estate | 2024 |
| Pearces Farm Shop Ltd | Wholesale & retail | 2013 |
| Peartree Wood Ltd | Real estate | 2020 |
| Peek Creative Limited | Professional & scientific | 2009 |
| Pelham Building Ltd | Construction | 2018 |
| Pelham Farming Company Limited | Agriculture & fishing | 2000 |
| Pelhampumps Ltd. | Manufacturing | 2016 |
| Penhill Assessing and Consulting Limited | Education | 2022 |
| Peppermint Balloons Limited | Wholesale & retail | 2018 |
| Peter Makewell Installations Limited | Construction | 1999 |
| Peter S Toms Ltd | Manufacturing | 2024 |
| Pinniped | Wholesale & retail | 2018 |
| Pitt Build Ltd | Construction | 2024 |
| Plantagenet Carpentry & Joinery Limited | Construction | 2006 |
| PLAY4PAWS Limited | Other services | 2020 |
| Plum Health Limited | Health & social care | 2015 |
| PMC (2011) Limited | Financial services | 2011 |
| PMC Polythene Limited | Manufacturing | 1989 |
| PMC Polythene Trustee Limited | Extraterritorial | 2026 |
| Ponko Limited | Professional & scientific | 2015 |
| Power Security Generators Limited | Manufacturing | 2012 |
| Prestige Cleaning Services Inc Limited | Administrative & support | 2020 |
| Prestige Homes (Cambs) Ltd | Construction | 2019 |
| Protect the Pelhams Ltd | Extraterritorial | 2023 |
| Prowall Limited | Construction | 2018 |
| Publicana UK Ltd | Hospitality | 2025 |
| Pure Heart Management Ltd | Hospitality | 2022 |
| PXC Ltd | Wholesale & retail | 2023 |
| Quaintance Consultancy Limited | Professional & scientific | 2016 |
| R. Sack Electrics Ltd. | Construction | 2000 |
| Raff & Everley Limited | Construction | 2019 |
| Rafumoe Ltd | Information & communication | 2024 |
| RB Energy Consulting Ltd | Professional & scientific | 2017 |
| RDC Coaching Ltd | Other services | 2022 |
| Red House Buntingford Limited | Real estate | 2014 |
| Redstow Renewables Holdco Ltd | Energy | 2020 |
| Redstow Renewables Limited | Energy | 2012 |
| Reed Autos Limited | Wholesale & retail | 2012 |
| Rejourney Limited | Professional & scientific | 2025 |
| Residence and Estate Management Limited | Households | 2022 |
| Revive Windows & Doors Limited | Construction | 2022 |