| Betts Properties (March) Limited | Real estate | 2015 |
| Bilsdale Ltd | Professional & scientific | 2023 |
| Binghamcourt Limited | Other services | 1995 |
| Biofresh Safestore Limited | Other services | 2022 |
| Blakwater Limited | Professional & scientific | 2003 |
| Blue Merle Property Ltd | Real estate | 2021 |
| Bluestone Property Management (March) Ltd. | Households | 2019 |
| Boston Plumbing Ltd | Construction | 2013 |
| Bravo Capital (March) Ltd | Construction | 2022 |
| Bravo Investment Ventures Ltd | Real estate | 2018 |
| Bravo Property Developments Ltd | Real estate | 2025 |
| Bravo Realty Group Ltd | Financial services | 2025 |
| Bridge Street (March) Limited | Construction | 2025 |
| Brightside Estates Ltd | Real estate | 2024 |
| Brittons Waste Clearance Services Ltd | Water & waste | 2023 |
| Broomfield Equity Ltd | Households | 2024 |
| Brown Housing Holdings Limited | Financial services | 2020 |
| Browns Housing Limited | Real estate | 2020 |
| Burlingfact Limited | Manufacturing | 1973 |
| Busy People Ltd | Administrative & support | 2022 |
| Cafe Express (Cambs) Limited | Hospitality | 2017 |
| Calpallun Ltd | Real estate | 2024 |
| CAM Design Consultancy Ltd | Professional & scientific | 2021 |
| Cambridge Confectionery Company Ltd | Manufacturing | 2018 |
| Cambridge Natural Solutions Limited | Professional & scientific | 2012 |
| Cambridgeshire Brickwork Ltd | Construction | 2014 |
| Cambridgeshire Hair and Beauty Ltd | Other services | 2020 |
| Cambridgeshire Medical Aesthetics Ltd | Other services | 2019 |
| Cambridgeshire Van Hire Ltd | Administrative & support | 2007 |
| Campbell Surveying Services Ltd | Professional & scientific | 2019 |
| Canalbs Limited | Information & communication | 1996 |
| Capital Artist Publishing Ltd | Information & communication | 2023 |
| Capital Roofing and Upvc Limited | Construction | 2023 |
| Cashiering Solutions Ltd | Professional & scientific | 2013 |
| Cassanos Café Limited | Hospitality | 2018 |
| Cedar Rose Limited | Real estate | 2024 |
| Cerbera Enterprises Limited | Financial services | 2020 |
| Cerbera Holdings Limited | Financial services | 2020 |
| Chaos Internet Ltd | Administrative & support | 2007 |
| Chapel Cottage Plants Limited | Wholesale & retail | 1994 |
| Chapman Farms Ellington Ltd | Agriculture & fishing | 2014 |
| Charles Trewin Ltd | Administrative & support | 2022 |
| Charlie Capital (March) Limited | Real estate | 2022 |
| Chatteris Leisure Ltd | Arts & recreation | 1995 |
| Chauntry House Investments Limited | Real estate | 2022 |
| Chris Deighton Builders Limited | Construction | 2008 |
| Churchgate (March) Limited | Real estate | 2024 |
| Churchgate Lease Co Limited | Real estate | 2024 |
| Citrus Sharp Designs Ltd | Wholesale & retail | 2019 |
| Claridge Cooling & Heating Ltd | Construction | 2020 |
| Classic Firearms UK Ltd | Manufacturing | 2022 |
| Clifford J Mottram & Sons Limited | Agriculture & fishing | 1976 |
| Clinical Psychology Service Ltd | Health & social care | 2011 |
| Clinicore Consultancy Limited | Other services | 2025 |
| Cmac Properties Limited | Real estate | 2018 |
| Cncraft Ltd | Manufacturing | 2024 |
| Coachmakers Ltd | Hospitality | 2022 |
| Codeberry Limited | Information & communication | 2015 |
| Codlicious Ltd | Hospitality | 2019 |
| Codlicious on Wheels Ltd | Hospitality | 2026 |
| Cole Properties (Manea) Limited | Construction | 2006 |
| Cole's Catering (March) Ltd | Hospitality | 2025 |
| Comers Consultancy Limited | Administrative & support | 2021 |
| Commercial Utility Brokers (UK) Ltd. | Extraterritorial | 2010 |
| Compact Mini Loaders Hire & Sales (East Anglia) Ltd | Administrative & support | 2019 |
| Coneywood Kennels Ltd | Agriculture & fishing | 2015 |
| Cook Family Vintage Tea Room Limited | Hospitality | 2018 |
| Cooke Construction and Renovation Limited | Construction | 2023 |
| Coolavin Holdings Limited | Professional & scientific | 1982 |
| Copied & Cloned Ltd | Wholesale & retail | 2016 |
| Corinamorgan Ltd | Health & social care | 2020 |
| Cornpool Limited | Construction | 2017 |
| County Campers Ltd | Manufacturing | 2017 |
| Cozens & Dean Limited | Financial services | 2002 |
| Crackling Creek Catering Limited | Hospitality | 2010 |
| Creating Better Together Limited | Education | 2025 |
| Creek Farms Limited | Agriculture & fishing | 1946 |
| Creese Homes Limited | Construction | 2001 |
| Critical Infrastructure Services Ltd | Construction | 2022 |
| CROP4SIGHT Limited | Professional & scientific | 2019 |
| Croplife UK Ltd | Other services | 1979 |
| Crouchmann UK Limited | Professional & scientific | 2006 |
| CUB (UK) Ltd | Administrative & support | 1999 |
| CWS Management Services Limited | Administrative & support | 2014 |
| Czech Real Ltd | Administrative & support | 2010 |
| D Stacey Drylining Limited | Construction | 2022 |
| D. & R. Hankins (Manea) Limited | Transport & logistics | 1979 |
| D. and J. Transport Limited | Transport & logistics | 1986 |
| D.H.Deptford(Farms)Limited | Agriculture & fishing | 1958 |
| Daddy Cabs Ltd | Transport & logistics | 2015 |
| Dale Fold Farms (Coates) Limited | Agriculture & fishing | 1977 |
| DAN Harradine Ltd | Real estate | 2025 |
| Danie Treurnicht Dentist Limited | Health & social care | 2008 |
| Dapallets Limited | Manufacturing | 2016 |
| Darius UMS Ltd | Professional & scientific | 2021 |
| DARRENS3DPRINTS Ltd | Manufacturing | 2026 |
| David Barton (Potatoes) Limited | Wholesale & retail | 1976 |
| David Boddy Quality Management Limited | Professional & scientific | 2019 |
| Daytona Contracting Ltd | Water & waste | 2007 |
| DC Card Events Ltd | Administrative & support | 2026 |