| Morgans Butchery Ltd | Wholesale & retail | 2018 |
| Morston Limited | Professional & scientific | 2006 |
| Mosaic Community Services CIC | Health & social care | 2026 |
| Motormedic Test Centre Ltd | Wholesale & retail | 2024 |
| Moxie Electrical Services Limited | Construction | 2019 |
| Moyns Park Estate Limited | Agriculture & fishing | 2007 |
| MPN Joinery Ltd | Manufacturing | 2013 |
| MR WU Takeaway Ltd | Hospitality | 2022 |
| MTA Health Care Solution Ltd | Administrative & support | 2013 |
| Mtsw Property Ltd | Real estate | 2025 |
| Mulhauser Consulting Ltd | Information & communication | 2002 |
| Munnings Medical Ltd | Health & social care | 2016 |
| MW Build & Design Ltd | Construction | 2021 |
| MXC Drive Limited | Transport & logistics | 2020 |
| My Tax Partner Limited | Professional & scientific | 2024 |
| Mycube Limited | Information & communication | 2006 |
| N & S Building Services (Cambridge) Limited | Administrative & support | 2003 |
| N C Brickwork Ltd | Construction | 2012 |
| N&S Retail Trading Limited | Wholesale & retail | 2025 |
| N.Ward Brickwork Ltd | Construction | 2019 |
| N7 Holdings Limited | Administrative & support | 2017 |
| N7 Property Limited | Real estate | 2017 |
| Naca Ltd | Transport & logistics | 2022 |
| Nafi Properties Ltd | Real estate | 2009 |
| Nakon Ltd | Transport & logistics | 2017 |
| Natalia Care Limited | Health & social care | 2016 |
| Nature's Defence Holdings Limited | Financial services | 2010 |
| Nature's Defence Research Ltd | Professional & scientific | 2009 |
| Nav's West Ltd | Health & social care | 2014 |
| Nbstormsway Limited | Real estate | 2024 |
| Neacsanicolae Limited | Wholesale & retail | 2017 |
| Neagle Capital Limited | Financial services | 2019 |
| Nealestone Farms Limited | Agriculture & fishing | 1933 |
| Neapolitan Style Pizza Limited | Hospitality | 2022 |
| Necesitar Ltd | Wholesale & retail | 2024 |
| NED Building Ltd | Construction | 2018 |
| Neptune Water Services Ltd | Professional & scientific | 2019 |
| Nest EGG Properties Limited | Real estate | 2018 |
| Nest EGG Property Solutions Ltd | Real estate | 2018 |
| Netherfield Partners Ltd | Professional & scientific | 2016 |
| New Horizon Properties Limited | Real estate | 1982 |
| New Suffolk Service Limited | Wholesale & retail | 2011 |
| Newton David Limited | Professional & scientific | 2016 |
| Newton Trade & Investment Limited | Real estate | 2015 |
| Nezerel Resources Limited | Wholesale & retail | 2026 |
| NH Kitchens & Building Ltd | Construction | 2018 |
| Nicell Limited | Construction | 2008 |
| Nigel Seed Limited | Information & communication | 2018 |
| Nine Bell Property Ltd | Construction | 2022 |
| Nine Rosina Limited | Real estate | 2026 |
| NJB Law Limited | Real estate | 2014 |
| NM Prime Properties Ltd | Real estate | 2024 |
| Nonpareil Rentals Limited | Real estate | 1960 |
| North Cheshire Estates Limited | Real estate | 1976 |
| North Devon Pest Control Limited | Administrative & support | 2014 |
| Nortopoly Ltd | Real estate | 2020 |
| Noviawater Nanotech Limited | Professional & scientific | 2026 |
| Noya RAJ Mahal Ltd | Hospitality | 2022 |
| NTH Express Couriers Limited | Transport & logistics | 2025 |
| Nulec Ltd | Construction | 2016 |
| Nutrida Ltd | Manufacturing | 2026 |
| NVK Transport 28 Ltd | Transport & logistics | 2014 |
| Nyotech Limited | Professional & scientific | 2018 |
| Office Problems Solved (Seating) Limited | Manufacturing | 2001 |
| Office Problems Solved Limited | Extraterritorial | 2013 |
| OH Pepi Ltd | Wholesale & retail | 2022 |
| OIL Burner Tech Ltd | Construction | 2016 |
| OIL Pump Intelligence Limited | Manufacturing | 2016 |
| Olive Homes & Interiors Ltd | Real estate | 2024 |
| Ollie Rush Golf Limited | Wholesale & retail | 2020 |
| ON Point PS Ltd | Construction | 2026 |
| One Posh Party Ltd | Wholesale & retail | 2012 |
| Onions Yard Developments Ltd | Construction | 2020 |
| Onwards & Upwards (Recruitment) Ltd | Administrative & support | 2022 |
| Orderbox Ltd | Information & communication | 2026 |
| Orion Biomedical Limited | Professional & scientific | 2024 |
| Overall Protection, H&S Consultancy Ltd | Professional & scientific | 2025 |
| Oxford Recognition Limited | Information & communication | 2005 |
| Ozan 18 Ltd | Hospitality | 2024 |
| P F Construction (GB) Ltd | Construction | 2010 |
| P&I General Construction Ltd | Construction | 2017 |
| P.G. Bailey & SON Ltd | Construction | 2003 |
| Pacegtm Limited | Professional & scientific | 2026 |
| Pack IDS Ltd. | Professional & scientific | 2017 |
| Packet Storm Limited | Information & communication | 2006 |
| Pal@Cambridge Ltd | Wholesale & retail | 2019 |
| Paradigm Advisory Ltd | Professional & scientific | 2026 |
| Paradox Accounting Limited | Professional & scientific | 2021 |
| Paradox Business Consultancy Limited | Professional & scientific | 2021 |
| Paradox Group Limited | Financial services | 2021 |
| Paramud Interiors Ltd | Construction | 2018 |
| Parker Brothers Group Limited | Financial services | 2017 |
| Parkway (Haverhill) Ltd | Wholesale & retail | 2015 |
| Paterson and SON Limited | Construction | 2006 |
| Paul Page Ltd | Construction | 2021 |
| Pavel Ardelean Trans Limited | Transport & logistics | 2013 |
| Peaches Bunting Ltd | Manufacturing | 2023 |
| Peacock Joinery Limited | Construction | 2009 |
| People Place Public Art CIC | Professional & scientific | 2025 |
| Permex Systems Limited | Manufacturing | 2003 |