| Costello Medical Consulting Limited | Professional & scientific | 2008 |
| Costello Medical Global Limited | Professional & scientific | 2025 |
| Costello Medical Trustee Limited | Financial services | 2026 |
| Costras Mechanic Ltd | Manufacturing | 2025 |
| Cosway Logistics Ltd | Wholesale & retail | 2025 |
| Cosy Goose Accommodation Limited | Hospitality | 2025 |
| COSY52 Ltd | Households | 2019 |
| Cosyaurora Ltd | Wholesale & retail | 2020 |
| Cotofana CD Limited | Manufacturing | 2017 |
| Coton Orchard Limited | Real estate | 1995 |
| Coton Village Hall | Arts & recreation | 2009 |
| Cotswold Hills Country Park Limited | Wholesale & retail | 2020 |
| Cottenham Sawmills Limited | Manufacturing | 2009 |
| Cottenham Tyre & Auto Ltd | Wholesale & retail | 2013 |
| Cottenham Vvip Limited | Wholesale & retail | 2023 |
| Cotto Cambridge Limited | Hospitality | 2008 |
| Cottontails Preschool CIC | Education | 2020 |
| Cougar Management Foundation | Extraterritorial | 2022 |
| Couler Ltd | Professional & scientific | 2025 |
| Coulibaly Trading Compagny. Ltd | Agriculture & fishing | 2026 |
| Coulson & SON Limited | Construction | 1980 |
| Coulson Group (Cowley Road) Ltd | Real estate | 2023 |
| Coulson Group Limited | Professional & scientific | 1920 |
| Coulson Joinery Limited | Manufacturing | 1966 |
| Council Farm Limited | Agriculture & fishing | 2025 |
| Council of Professional Chaplains and Pastoral Carers Limited | Professional & scientific | 2015 |
| Country Club (IK) Limited | Information & communication | 2022 |
| Country Club Clothing Limited | Wholesale & retail | 2024 |
| Countryhealth Limited | Health & social care | 2014 |
| Countryside Burials Limited | Other services | 1999 |
| County Heating and Plumbing Limited | Construction | 2003 |
| County Windows (Cambridge) Ltd | Construction | 2013 |
| Countycrops Limited | Agriculture & fishing | 1993 |
| Courtneys London Limited | Professional & scientific | 2017 |
| Courts & Quads Ltd | Wholesale & retail | 2023 |
| Courtyards Management Limited | Households | 1961 |
| Coury & Company Limited | Real estate | 2006 |
| Cousins of Newnham Ltd | Real estate | 2016 |
| Coutts Consultancy and Sales Ltd | Professional & scientific | 2022 |
| Covalab UK Limited | Professional & scientific | 2002 |
| Coverandcarry Limited | Agriculture & fishing | 2016 |
| Covill Skip Hire Limited | Water & waste | 2025 |
| Cowin BO Site Commodity Co., Ltd | Extraterritorial | 2017 |
| Cowley Park (Donington) Management Company Limited | Households | 2018 |
| Cowley Park (Town DAM Lane P2) Management Company Limited | Households | 2021 |
| Cowley Road Garage Ltd | Wholesale & retail | 2017 |
| Coxshaw Property Holdings Limited | Real estate | 2023 |
| Cozy Pets Boutique Hotel Ltd | Other services | 2022 |
| Cp&H Limited | Construction | 2014 |
| Cpd.Ventures Ltd | Professional & scientific | 2025 |
| CPJ Education Limited | Education | 2020 |
| CPL One Group Limited | Information & communication | 2016 |
| CPL One Ltd | Professional & scientific | 1996 |
| CPO Aero Maintenance Ltd | Manufacturing | 2022 |
| CPS Building Services Limited | Construction | 2002 |
| CR Capital Limited | Financial services | 2018 |
| Cradle Biotech Ltd | Professional & scientific | 2025 |
| Cradle Global Ltd | Manufacturing | 2024 |
| Crafteak Ltd | Manufacturing | 2024 |
| Craftmaster Restorations Ltd | Professional & scientific | 2024 |
| Crafton Limited | Financial services | 1999 |
| Crafts for Home Ltd | Wholesale & retail | 2022 |
| Craftsmen Chamois Limited | Manufacturing | 1995 |
| Crafty Kitchen Ltd | Hospitality | 2022 |
| Crafty Pints Limited | Manufacturing | 2019 |
| Crafty Pubs Ltd | Hospitality | 2013 |
| Craig Boyd Engineering Limited | Wholesale & retail | 2015 |
| Craig Carter Design Ltd | Professional & scientific | 2022 |
| Craig Cook Locations Ltd. | Administrative & support | 2018 |
| Craig Gilks Ltd | Extraterritorial | 2022 |
| Craig Mckenzie Construction Plant Hire Limited | Administrative & support | 2026 |
| Craig Mckenzie Holdings Limited | Financial services | 2025 |
| Craig Mckenzie Property Limited | Real estate | 2026 |
| Cralr Ltd | Professional & scientific | 2021 |
| Crane Solar Limited | Real estate | 2023 |
| Cranesbill Developments Limited | Construction | 2017 |
| Cranesbill Investments Limited | Real estate | 2021 |
| Cranford Bloodstock Ltd | Agriculture & fishing | 2006 |
| Cranmer Estates Limited | Information & communication | 2016 |
| Cranmer Residential Limited | Information & communication | 2021 |
| Cranwell Consulting Ltd | Professional & scientific | 2023 |
| Cranwell Court Freehold Limited | Real estate | 2002 |
| Cranwell Court Management Limited | Real estate | 1977 |
| Crash Barrier (Flitwick) Limited | Information & communication | 1987 |
| Craven Conservation & Restoration Ltd | Other services | 2017 |
| Crawley Lodge Management Limited | Households | 1969 |
| Cray Fashions | Real estate | 1953 |
| Crayfish.Io Ltd | Administrative & support | 2016 |
| Crdc C&M Limited | Construction | 2025 |
| Creasallis Ltd | Professional & scientific | 2021 |
| Crease Drove (Crowland) Management Company Ltd | Households | 2019 |
| Crease Drove (Woodroffe) Management Company Ltd | Households | 2020 |
| Creatar Ltd | Other services | 2011 |
| Create Signs Ltd | Manufacturing | 2011 |
| Create Space Ltd | Construction | 2005 |
| Creationelle Limited | Other services | 2018 |
| Creative Build & Interiors Ltd | Construction | 2008 |
| Creative Bureau Ltd | Information & communication | 2007 |
| Creative Consulting London Limited | Administrative & support | 2008 |
| Creative Culture Capital Ltd | Arts & recreation | 2017 |