| Moule Holdings Ltd | Financial services | 2019 |
| Moussa Direct Limited | Wholesale & retail | 1986 |
| Movable Type Limited | Information & communication | 1987 |
| MR. Polito's Barber Shops Limited | Other services | 1996 |
| MRL Public Sector Consultants Limited | Professional & scientific | 2002 |
| MT Cars Limited | Wholesale & retail | 2004 |
| Mudey’S Ltd | Hospitality | 2025 |
| Mumums Market Ltd | Wholesale & retail | 2019 |
| Muslim Butchers Ltd | Wholesale & retail | 2004 |
| MXI Services Ltd | Construction | 2007 |
| N. & C. Glass Ltd. | Construction | 1993 |
| N.J. Domestic Services Ltd | Other services | 2003 |
| N.P.K. Holdings Limited | Construction | 1864 |
| Nascenta Ltd | Information & communication | 1999 |
| Nash Fordham Limited | Professional & scientific | 1933 |
| Nationwide Training and Safety Services Ltd | Education | 2007 |
| Natures Candy Limited | Other services | 2020 |
| Nayroh Limited | Real estate | 2025 |
| NBS Biologicals Limited | Manufacturing | 1994 |
| Nero Hairdressing Ltd | Other services | 2005 |
| Networking Support Services Ltd | Information & communication | 2006 |
| NHR Civil Structural Engineering Ltd | Professional & scientific | 2005 |
| Nicola Rule Limited | Real estate | 2007 |
| Niemczuk Limited | Real estate | 2004 |
| Northstar Trading Company Limited | Wholesale & retail | 1982 |
| O'Sullivan Shopfitting (Cambridge) Limited | Construction | 1997 |
| Officestor Limited | Wholesale & retail | 2002 |
| OIL - DRI (U.K.) Limited | Manufacturing | 1975 |
| Ollington Electrical Limited | Construction | 1976 |
| One Desk IT Ltd | Information & communication | 2026 |
| Ontology Labs Ltd | Agriculture & fishing | 2016 |
| Opal Food Processing Systems Limited | Manufacturing | 1996 |
| Orson Solutions Ltd | Professional & scientific | 2007 |
| Over Communications and Electrical | | 1986 |
| P D Askew Property Services Limited | Information & communication | 2004 |
| PAN Computer Consultancy Limited | Information & communication | 2002 |
| Papa Holdings Corporation Ltd | Financial services | 2018 |
| Papa IP Limited | Administrative & support | 2018 |
| Paradise Software Limited | Information & communication | 1999 |
| Parametric Investments Limited | Manufacturing | 2004 |
| Parmhill Properties Limited | Real estate | 2000 |
| Paul Binns Commercials Limited | Wholesale & retail | 1997 |
| Paul Bird Ltd | Other services | 2003 |
| Paul Carter Consultants (UK) Ltd | Professional & scientific | 1983 |
| Paul Isbell Plumbing & Heating Limited | Construction | 2006 |
| Pavemac Limited | Manufacturing | 2006 |
| Pegasi Bloodstock Limited | Information & communication | 2003 |
| Pet Gear Limited | Construction | 1998 |
| Peter Audus Limited | Construction | 1987 |
| Peter Lane & Partners (ST Neots) Limited | Real estate | 2002 |
| Peterborough Cathedral (Enterprises) Limited | Extraterritorial | 1987 |
| Peterhouse Enterprises Limited | Construction | 1995 |
| Pharma Insight Ltd | Wholesale & retail | 2005 |
| Photofabrication Ltd | Manufacturing | 1971 |
| Pilot Homes and Properties Limited | Real estate | 2022 |
| Pisces Office Support Limited | Professional & scientific | 2003 |
| Planoramic Limited | Professional & scientific | 2000 |
| PMV Heating and Plumbing Ltd. | Construction | 2005 |
| Pocketmoney Travel Limited | Wholesale & retail | 2001 |
| Point Professional Recruitment Limited | Administrative & support | 1992 |
| PPO Ltd | Professional & scientific | 2018 |
| Prabash Ltd | Hospitality | 2020 |
| Priden Engineering Limited | Manufacturing | 2001 |
| Priority Golf Limited | | 1991 |
| Prism Surveys Limited | Construction | 2003 |
| Proedge Group Holdings Limited | Financial services | 2025 |
| PSG Refrigeration Limited | Other services | 2007 |
| Pure Indigo Limited | Information & communication | 2005 |
| PX Cables Limited | Financial services | 2002 |
| PX Manufacturing Ltd | Manufacturing | 1994 |
| PXM Holdings Ltd | Professional & scientific | 1986 |
| Quadro Harston Limited | Financial services | 1986 |
| Queensbury Properties (Newmarket) Limited | Extraterritorial | 2004 |
| Queensgate Estates Limited | Professional & scientific | 1987 |
| Qwest Livestock Ltd. | Professional & scientific | 2003 |
| R & M Bentley (Motor Factors) Limited | Wholesale & retail | 1979 |
| R J Warren Estates Ltd | Real estate | 2007 |
| R.E. Thornhill Limited | Real estate | 1952 |
| R.T. Motors (UK) Ltd | Wholesale & retail | 2006 |
| R.W.Franklin & SON Limited | Agriculture & fishing | 1955 |
| R.Y.R. Community Liaison Consultants Ltd | Administrative & support | 2013 |
| Race Support Limited | Wholesale & retail | 2005 |
| Rachel Parker Limited | Professional & scientific | 2006 |
| Railway Project Management Ltd | Professional & scientific | 2006 |
| Ramsey Paint Company Limited | Wholesale & retail | 1991 |
| Raphael Learning & Development Limited | Professional & scientific | 2008 |
| Rapid Employment and Recruitment Limited | Administrative & support | 2000 |
| Rapidrop Bidco Limited | Administrative & support | 2024 |
| Rapidrop Topco Limited | Financial services | 2024 |
| RBF Festivals Limited | Arts & recreation | 2004 |
| Reborn Furniture Ltd | Manufacturing | 2020 |
| Remark Global Limited | Construction | 2006 |
| Rendezvue Ltd. | Hospitality | 2004 |
| Renovare Properties Cambridge Limited | Construction | 2024 |
| Repindex Limited | Professional & scientific | 2000 |
| Rezai Consulting Limited | Professional & scientific | 2001 |
| Ricedon Engineering Limited | | 1978 |
| Richard Stanfield Limited | Wholesale & retail | 2004 |
| Rising Curve LLP | | 2007 |
| Rivelin Bridge Ltd | Professional & scientific | 2017 |