| C & E Strong Limited | Administrative & support | 2020 |
| C & G P Ltd | Construction | 2024 |
| C and D Contracting Limited | Agriculture & fishing | 2007 |
| C B Mech Limited | Manufacturing | 2017 |
| C L Electrical Limited | Construction | 2018 |
| C M James Ltd | Information & communication | 2024 |
| Café Mountain Coffee Limited | Manufacturing | 2026 |
| Calco Construction Limited | Construction | 2006 |
| Calkin Construction and Project Management Services Ltd | Construction | 2011 |
| Candp Services Limited | Construction | 2025 |
| Capsol Leasing Limited | Administrative & support | 2014 |
| Carbury Holdings Ltd | Real estate | 2018 |
| Card-E-Diem Ltd | Administrative & support | 2026 |
| Carisbrooke Stud Estate Limited | Agriculture & fishing | 2024 |
| Carisbrooke Stud LLP | | 2024 |
| Carlo Creates Limited | Professional & scientific | 2024 |
| Cars International Service Limited | Wholesale & retail | 2006 |
| Casa Ferrini Limited | Manufacturing | 2025 |
| Castle Scenery Limited | Manufacturing | 2026 |
| Catering Know HOW Ltd | Hospitality | 2020 |
| Caudwell Mitchell Developments Limited | Financial services | 2024 |
| CAVPROP1 Limited | Financial services | 2019 |
| Ccet Limited | Professional & scientific | 2020 |
| CCW Building & Landscaping Ltd | Construction | 2024 |
| Cedis Advisors Ltd | Professional & scientific | 2023 |
| Central Area Heat Company Limited | Energy | 2016 |
| Central Bloc Limited | Information & communication | 2021 |
| Central Ventilation Distribution Ltd | Construction | 2026 |
| CGS Construction Consultants Ltd | Other services | 2013 |
| CGS Garage Services Limited | Wholesale & retail | 2013 |
| CGS Solutions Limited | Financial services | 2024 |
| Chai Shai an Limited | Hospitality | 2023 |
| Channel Experts Group Limited | Professional & scientific | 2020 |
| Chapel Forge Farriers Limited | Agriculture & fishing | 2003 |
| Charlie Mann Racing Limited | Arts & recreation | 1991 |
| Charnham Court Management Limited | Households | 2001 |
| Charnham Meadow Limited | Real estate | 2012 |
| Charnham Software Limited | Information & communication | 2020 |
| Charthan House Limited | Professional & scientific | 2007 |
| Chatha Box Limited | Real estate | 2025 |
| Chelfham Mills Ltd | Real estate | 2016 |
| Chelsea Quavers Ltd | Education | 2021 |
| Cheriton Estates Limited | Real estate | 2014 |
| Cherry Blossom Meadow (Newbury) Management Company Limited | Households | 2019 |
| Chesters Fish & Chips Restaurant Limited | Hospitality | 2020 |
| Chimney Pots Limited | Administrative & support | 2002 |
| Chleo Limited | Real estate | 1993 |
| Chobham Club Redevelopment Limited | Construction | 2023 |
| CHR. Hansen (UK) Limited | Manufacturing | 1916 |
| Chris Coen Films Ltd | Administrative & support | 2005 |
| Christopher Rushbrooke Associates Limited | Wholesale & retail | 2005 |
| Church View House (Drewsteignton) Limited | Households | 1982 |
| Circle 10 Consultancy Ltd | Information & communication | 2015 |
| Circles of Strength Therapy Limited | Health & social care | 2021 |
| CJ Electrical (Southern) Limited | Construction | 2020 |
| CJP Motorsport Limited | Professional & scientific | 2025 |
| CKG Management Limited | Real estate | 2024 |
| Clayden Allenby Ltd | Information & communication | 2020 |
| Clayton Farriers Limited | Administrative & support | 2018 |
| Cleanslate (Hurstbourne Priors) Ltd | Construction | 2015 |
| Cleanslate (Weston) Ltd | Professional & scientific | 2013 |
| Cleanslate Ashford Ltd | Construction | 2016 |
| Cleanslate Construction Limited | Construction | 2025 |
| Cleanslate Group Limited | Financial services | 2023 |
| Cleanslate Land Limited | Construction | 2014 |
| Cleanslate Ltd | Construction | 2011 |
| Cleeve Executive Recruitment Limited | Administrative & support | 2018 |
| Clere Identities Limited | Administrative & support | 2001 |
| Clive COX Racing Limited | Arts & recreation | 2006 |
| Cloudforce International Ltd | Information & communication | 2020 |
| CMC Business Advisers Ltd | Professional & scientific | 2020 |
| Coachman Catering Limited | Hospitality | 2021 |
| Cobbs Farm Co. Limited | Hospitality | 2006 |
| Cobi Procurement Ltd | Professional & scientific | 2026 |
| Coffee CUP (Shrewsbury) Limited | Hospitality | 2019 |
| Coffee Southwest Ltd | Wholesale & retail | 2017 |
| Colebream Estates Limited | Real estate | 1935 |
| Coles Cabs Limited | Transport & logistics | 2026 |
| Coles Restoration Limited | Construction | 2024 |
| Collingbourne Coatings Limited | Administrative & support | 2007 |
| Colwell Solutions Limited | Wholesale & retail | 2016 |
| Comfort Properties (UK) Limited | Professional & scientific | 2001 |
| Command-R Limited | Information & communication | 2023 |
| Compilator Ltd | Information & communication | 2000 |
| Compressor Products International Limited | Manufacturing | 1984 |
| Conker Coaching and Consulting Ltd | Professional & scientific | 2022 |
| Connex Consultancy Limited | Professional & scientific | 2024 |
| Considered Automotive Limited | Wholesale & retail | 2025 |
| Constantine Professional Advisers Limited | Professional & scientific | 2021 |
| Consultniks Ltd | Professional & scientific | 2006 |
| Cooper & Cooper Hungerford Ltd | Wholesale & retail | 2019 |
| Cooper Property Improvements Ltd | Administrative & support | 2016 |
| Corinium Homes Ltd | Real estate | 2015 |
| Corvia Limited | Information & communication | 2009 |
| Cotswold Aquarius Ltd | Manufacturing | 2025 |
| Cotton Group Ltd | Real estate | 2024 |
| Country Food & Dining (2) Limited | Wholesale & retail | 2008 |
| Country Food & Dining (3) Limited | Wholesale & retail | 2008 |
| Courage & Care Ltd | Wholesale & retail | 2026 |
| COX Properties Limited | Real estate | 2016 |