| A & G Conservatories Limited | Construction | 2001 |
| A & K Haulage Limited | Transport & logistics | 2007 |
| A N Scarratt Plumbing & Central Heating Ltd | Construction | 2005 |
| A-Star Flooring Services Limited | Construction | 2024 |
| A.H.T Electrical Ltd | Construction | 2006 |
| Action Centres UK Limited | Hospitality | 1989 |
| Acumenmc Limited | Professional & scientific | 2003 |
| Adees Ltd | Other services | 2007 |
| ADI Technology Solutions Ltd | Information & communication | 2015 |
| Alimak Group UK Ltd | Manufacturing | 1968 |
| Allegro Music (Kettering) | | 1990 |
| Allehro Music (Kettering) | | 1991 |
| Alltranz Limited | Professional & scientific | 2006 |
| Alpha Carpet & Flooring Ltd | Construction | 2005 |
| ALS Limited | Manufacturing | 1993 |
| Anderson Property Solutions Limited | Construction | 2007 |
| Andrew Davies Brickwork Limited | Construction | 2006 |
| Anglia-Matics Limited | | 1959 |
| Anstey & Associates Limited | Professional & scientific | 2006 |
| Apex Investment Properties Ltd | Real estate | 2025 |
| Architectural Metal Craftsmen Ltd | Manufacturing | 2006 |
| Architectural Solutions (Northampton) Ltd. | Professional & scientific | 2000 |
| Arron Door Services Limited | Other services | 1987 |
| Arthur Spriggs & Sons Limited | Transport & logistics | 1981 |
| Astral Mechanical Handling Limited | | 1981 |
| Atlantic Motion Limited | Information & communication | 2000 |
| Auto Garage Equipment Limited | Administrative & support | 2003 |
| Autowerks 2010 Limited | Wholesale & retail | 2009 |
| Avondale Motor Engineers Limited | Wholesale & retail | 2007 |
| B W Commercials Limited | Wholesale & retail | 2007 |
| B.S. Project Engineering Limited | Manufacturing | 1995 |
| Barker Shoes Limited | Manufacturing | 1914 |
| Belle Casa (Brighton) Limited | Administrative & support | 2009 |
| Benjity Ltd | Health & social care | 2024 |
| Berry Taylor | | 1996 |
| Bevan Court (Wellingborough) Management Company Limited | Real estate | 2003 |
| Block AID UK Limited | Public administration | 2019 |
| BLR Leisure Ltd | Arts & recreation | 2004 |
| Boat Inn (Stoke Bruerne) Limited(The) | Hospitality | 1984 |
| BOB Kirk Supplies Limited | Other services | 1987 |
| Brackley Motors & Building Contractors Limited | Extraterritorial | 1958 |
| Brad West Financial Planning Ltd | Professional & scientific | 2020 |
| Brands Limited | Wholesale & retail | 1996 |
| Buccleuch Property (Oxford) Limited | Real estate | 2021 |
| Buccleuch Property (Weston) Limited | Real estate | 2024 |
| Buccleuch Property (Woolwich) Ltd | Construction | 2025 |
| C & D Consultants Limited | Administrative & support | 2006 |
| C&M LEE Ltd | Transport & logistics | 2025 |
| C.A.J.L. Property Limited | Real estate | 2001 |
| C.G. Accounts Limited | Professional & scientific | 2003 |
| C.S.C. Subcontractors (UK) Limited | Wholesale & retail | 1992 |
| Carr Brothers U.K. Limited | Transport & logistics | 1978 |
| Castle Kebab Ltd | Hospitality | 2019 |
| Cento Consultancy Limited | Professional & scientific | 2014 |
| Cento Engineering Company Limited | Construction | 1995 |
| Cento Engineering Group Limited | Construction | 2014 |
| Cento Maintenance Limited | Construction | 2014 |
| Cento Training Limited | Education | 2012 |
| Centurian Parc Fermé Ltd | Wholesale & retail | 2023 |
| Chacombe Vehicle Rental Limited | Administrative & support | 2006 |
| Changing People Consultants Ltd | Administrative & support | 2006 |
| Charles E Thompson Partnership | | 2000 |
| Charles Horrell Shoes (Retail) Limited | | 1969 |
| Chbc Property Ltd | Construction | 2017 |
| Chicheley Cottages Management Company Limited | Households | 2000 |
| Chilled Express Ltd | Transport & logistics | 2004 |
| Chowns Mill Business Park Limited | Transport & logistics | 1988 |
| Clarke Electrical Services Ltd | Manufacturing | 2003 |
| Clockwork Distribution Systems Limited | | 1989 |
| CNC Turned Products Ltd | Manufacturing | 2018 |
| Co'Hort Manufacturing Limited | Manufacturing | 1994 |
| Commercial Fibreglass Limited | | 1988 |
| Connectwo UK Ltd | Other services | 2007 |
| Corby Silver Band Club Limited | Hospitality | 1965 |
| Country Builders Ltd | | 1983 |
| COY Consultancy Limited | Professional & scientific | 2006 |
| D & J Houses Ltd | Real estate | 2026 |
| D and S Autos (Northampton) Limited | Wholesale & retail | 2007 |
| D Joyce and Sons Limited | Wholesale & retail | 1996 |
| D.Howitt(Builders)Limited | Real estate | 1966 |
| D.J. Allen Electrical Contractors Limited | Energy | 2003 |
| Daventry Guarding Limited | Manufacturing | 1996 |
| DDW Catering Limited | Other services | 2007 |
| DE Agray Limited | Professional & scientific | 2005 |
| DFA Law LLP | | 2008 |
| DLW Property Maintenance Services Ltd | Other services | 2005 |
| Donna Salado Bridalwear Limited | Wholesale & retail | 1996 |
| DP Builders (Northants) Limited | Construction | 2002 |
| DR T&T Health UK Ltd | Wholesale & retail | 2010 |
| Droull Ltd | Professional & scientific | 2018 |
| Eastcote Grange Limited | Professional & scientific | 2001 |
| EC GAS & Power Limited | Wholesale & retail | 2016 |
| Elite Drywall Ltd | Construction | 2019 |
| Empa Media Limited | Information & communication | 2012 |
| Europhile (U.K.) Limited | Professional & scientific | 1991 |
| Eurusport Limited | Arts & recreation | 2007 |
| Evolution Paint & Graphic Ltd. | Administrative & support | 1997 |
| Evolution PR Limited | Professional & scientific | 2004 |
| Extreme TEC Limited | Professional & scientific | 2004 |
| Eymen Barber Ltd | Other services | 2018 |