| Brooks of Life Ministries International Limited | Other services | 2000 |
| Bross Outdoors Ltd | Wholesale & retail | 2017 |
| Bsqc Limited | Professional & scientific | 2003 |
| Buckby Health and Leisure Limited | Arts & recreation | 2007 |
| Bushboard Holdings Limited | Manufacturing | 2004 |
| Bushboard Limited | Manufacturing | 2000 |
| Buzzie Beas Limited | Health & social care | 2013 |
| C C S Leisure Limited | Arts & recreation | 2002 |
| C J'S Diner Limited | Hospitality | 2004 |
| C K Services R.C.E. Limited | Construction | 2005 |
| C R Scaife Limited | Construction | 2007 |
| C&K Trade Ltd | Wholesale & retail | 2023 |
| C.J.H. Builders | | 1997 |
| Calpara Logistics Limited | Transport & logistics | 2015 |
| Calsol Engineering Limited | Professional & scientific | 2007 |
| Cantor Barnard Ltd | Manufacturing | 1975 |
| Carpetline (U.K.) Limited | Wholesale & retail | 1993 |
| CDS Rewinds Limited | Manufacturing | 2003 |
| Centaur Business Ventures Limited | Professional & scientific | 1996 |
| Central Mosque Northampton | Other services | 2000 |
| Cerbera Limited | Professional & scientific | 2003 |
| Charles Thomas (UK) Limited | Real estate | 1986 |
| Chelton Brown Limited | Real estate | 2005 |
| Chestnut Court Maintenance Limited | Other services | 2004 |
| Chiplink Ltd | Information & communication | 2021 |
| Chris Knight Brickworks Limited | Construction | 2006 |
| Chromagen Limited | Manufacturing | 1996 |
| Church Meadow Flats Management Limited | Real estate | 1986 |
| Cityjoin Residents Management Limited | Real estate | 1988 |
| Clarke-Bukholt Marketing Ltd | Professional & scientific | 2006 |
| Classic Reclaims Limited | Wholesale & retail | 1996 |
| Clayton Builders Limited | Construction | 2003 |
| Close Motor Company Limited | Wholesale & retail | 1999 |
| CMW Technical Services Limited | Manufacturing | 2006 |
| Colton's Groomers Limited | Other services | 2021 |
| Combined Fleet Maintenance Limited | Wholesale & retail | 2003 |
| Comms Power Limited | Administrative & support | 2002 |
| Complink Software Limited | Information & communication | 1998 |
| Condyle Limited | Extraterritorial | 1995 |
| Conflict Studies Research Centre Ltd | Professional & scientific | 2010 |
| Connect Business Management Limited | Professional & scientific | 2002 |
| Connell Decorating Services Limited | Construction | 2005 |
| Construction Services (Duncote) Limited | Construction | 1997 |
| Contour Plant Limited | Professional & scientific | 1994 |
| Cookies Bakers & Confectioners Limited | Wholesale & retail | 2003 |
| Cool Express Limited | Transport & logistics | 2003 |
| Cornerstone Property Group Ltd | Construction | 2007 |
| Countrywise Communication Limited | Information & communication | 1994 |
| County Workwear Limited | Transport & logistics | 1987 |
| Credit Sureties Company Limited | Construction | 1955 |
| Crown Executive Cars Limited | Transport & logistics | 1999 |
| Crown Finance Corporation Limited | Financial services | 1980 |
| Curve Learning Limited | Professional & scientific | 2005 |
| Curvilinear Limited | Manufacturing | 1997 |
| Cygnet Systems Ltd | Administrative & support | 2006 |
| Cypet Services Limited | Manufacturing | 2005 |
| D Mahony & Sons Limited | Agriculture & fishing | 2002 |
| D S Pannell Decorators Limited | Construction | 2003 |
| D. Bonner Cars Limited | Wholesale & retail | 2006 |
| D. L. Howitt (Aquatics) Limited | Construction | 2007 |
| D. L. Howitt (Estates) Limited | Real estate | 2007 |
| D. Mallard Builder Limited | Construction | 2003 |
| D.B. Shoes Limited | Wholesale & retail | 1920 |
| Daglar Barber Ltd | Other services | 2024 |
| Dalocke.Com Limited | Administrative & support | 2026 |
| Darren Oliver Clues Menswear Limited | Wholesale & retail | 2004 |
| Datamemory Links Limited | Professional & scientific | 2004 |
| Datt Property Investment Limited | Transport & logistics | 2024 |
| Dave Murphy & Associates Ltd | Real estate | 2004 |
| Daventry Blinds Limited | Wholesale & retail | 1999 |
| David Green Electrical Limited | Construction | 2006 |
| Dawson Consultancy Limited | Professional & scientific | 2002 |
| DEC Technical Services Limited | Manufacturing | 2002 |
| Deep Heart Care Ltd | Health & social care | 2015 |
| Deluxe Footwear Limited | Wholesale & retail | 2007 |
| Dencom Limited | Real estate | 2004 |
| Dermot Mccarney Limited | Construction | 2003 |
| Derngate Enterprises Limited | Arts & recreation | 1993 |
| Desborough Brickwork Limited | Construction | 2005 |
| Die-Pat Divisions Limited | Wholesale & retail | 1994 |
| Die-Pat Holdings Limited | Professional & scientific | 1985 |
| Diepat Limited | Extraterritorial | 1966 |
| Digital Flair Media Limited | Information & communication | 2003 |
| Digital on Demand Limited | Information & communication | 2005 |
| Discus Group Limited | Manufacturing | 2000 |
| Diversey UK Holdings Limited | Manufacturing | 2001 |
| DMG Roofing Limited | Construction | 2003 |
| DR Martens Airwair & Co. Limited | Professional & scientific | 1951 |
| DR Martens Airwair Group Limited | Professional & scientific | 1992 |
| DR. Martens Sports & Leisure Limited | Professional & scientific | 1993 |
| Dragon 2000 Limited | Wholesale & retail | 1997 |
| Dragon Reclamation Limited | Water & waste | 1999 |
| Dram Good Books Limited | Information & communication | 2002 |
| Driso Ltd | Extraterritorial | 1999 |
| Dunlin Securities Limited | Administrative & support | 2006 |
| Duston Properties Ltd | Real estate | 2007 |
| DWD Tax Advisers Limited | Professional & scientific | 2003 |
| E. a. Tailby Components Limited | Manufacturing | 1994 |
| E.S.M Matsa Investments Ltd | Health & social care | 2023 |
| Eales Developments Limited | Real estate | 2004 |