| Collins Digital Ltd | Professional & scientific | 2023 |
| Colmenar Associates Limited | Professional & scientific | 2023 |
| Colmore Capital Limited | Construction | 2016 |
| Colmore Capital Ventures II Limited | Financial services | 2020 |
| Colmore Capital Ventures IV Limited | Financial services | 2021 |
| Colmore Capital Ventures Limited | Financial services | 2017 |
| Colmore Capital Ventures V Limited | Financial services | 2023 |
| Colmore Capital Ventures VI Ltd | Financial services | 2025 |
| Colmore Capital Ventures Viii Ltd | Financial services | 2025 |
| Colmore Consulting Midlands Ltd | Administrative & support | 2022 |
| Colmore Living Limited | Real estate | 2023 |
| Colour Material Finish Ltd | Professional & scientific | 2024 |
| Colste Holdings Limited | Real estate | 2020 |
| COM Group Holdings Ltd | Information & communication | 2025 |
| Combrook Property Services Ltd | Real estate | 2024 |
| Cometz Limited | Manufacturing | 2024 |
| Comfort Care PVT Ltd | Health & social care | 2022 |
| Commercial Insurance Brokers (B'Ham) Limited | Financial services | 1955 |
| Common Good Impact Foundation | Professional & scientific | 2021 |
| Common Good Partners Limited | Professional & scientific | 2014 |
| Common Story Limited | Information & communication | 2020 |
| Communication Property Services Limited | Information & communication | 2015 |
| Compass Health & Wellbeing Limited | Health & social care | 2016 |
| Complete Cover Recruitment Ltd | Administrative & support | 2021 |
| Compound Design Limited | Professional & scientific | 2007 |
| Compressortech Limited | Manufacturing | 1994 |
| Compton Verney Coach House Management Limited | Households | 1991 |
| Compton Verney Enterprises Limited | Wholesale & retail | 1995 |
| Compton Verney House Charity | Other services | 2021 |
| Compton Verney Limited | Professional & scientific | 1995 |
| Computax (UK) Limited | Information & communication | 1995 |
| Computer Repair MAN Limited | Information & communication | 2016 |
| Computer Repair MAN Services Ltd | Other services | 2026 |
| Computronics Limited | Other services | 2016 |
| Comtec Translations Limited | Professional & scientific | 2002 |
| Conceptability Limited | Professional & scientific | 2008 |
| Concierge Medical Group Ltd. | Health & social care | 2015 |
| Concierge Medical Practice Limited | Health & social care | 2013 |
| Connected Care Futures Limited | Professional & scientific | 2025 |
| Connexis Consult Limited | Information & communication | 2025 |
| Conrad Pope Electrical Services Limited | Construction | 2011 |
| Conrad-Kottler (Estates) Limited | Construction | 1988 |
| Consistency Group Limited | Administrative & support | 2019 |
| Consort Executive Solutions Limited | Professional & scientific | 2014 |
| Consort Properties Limited | Real estate | 1987 |
| Contemporary Stone Ltd | Manufacturing | 2012 |
| Continental Bottle Co. Limited | Wholesale & retail | 1991 |
| Continental Product Engineering Limited | Wholesale & retail | 1992 |
| Contrive Engineering Ltd | Professional & scientific | 2018 |
| Cooke Reynolds Ltd | Administrative & support | 2014 |
| Cookehouse Solutions Limited | Information & communication | 2005 |
| Cookie JAR Golf Limited | Information & communication | 2021 |
| Cooling Tower Projects Ltd | Professional & scientific | 2004 |
| Coopr Ventures Ltd | Professional & scientific | 2016 |
| COR1 Limited | Wholesale & retail | 2014 |
| Cordyline Aspire Limited | Professional & scientific | 2015 |
| Core Electrical (Midlands) Ltd | Construction | 2018 |
| Core Protect Limited | Financial services | 1999 |
| Corefield Procurement Ltd | Wholesale & retail | 2019 |
| Corkside Limited | Extraterritorial | 2017 |
| Corn Barn Management Company Limited | Households | 2023 |
| Corner Cottage Bakery Ltd | Manufacturing | 2020 |
| Cornwall Investment Properties Ltd | Households | 2017 |
| Corrie Nielsen Designs Limited | Arts & recreation | 2013 |
| Corstorphine & Wright (Central South) Ltd | Professional & scientific | 2010 |
| Corstorphine & Wright EBT Trustee Limited | Professional & scientific | 2019 |
| Corstorphine & Wright Holdings Limited | Financial services | 2019 |
| Corstorphine & Wright Limited | Professional & scientific | 1997 |
| Corstorphine & Wright New Co Limited | Extraterritorial | 2018 |
| Corunna Court Property Management Limited | Real estate | 2004 |
| Coshield Global Ltd | Wholesale & retail | 2019 |
| Cosmetosphera Ltd | Professional & scientific | 2018 |
| Cosmos Storage Ltd | Wholesale & retail | 2025 |
| Costumes 2U Limited | Wholesale & retail | 2004 |
| Costy COS Ltd | Transport & logistics | 2016 |
| Coton Park Management Limited | Administrative & support | 2000 |
| Cotswold Bespoke Fencing Ltd | Construction | 2024 |
| Cotswold Bridal Couture Limited | Wholesale & retail | 2024 |
| Cotswold Contemporary Limited | Wholesale & retail | 2020 |
| Cotswold Cosmetic Artistry Limited | Other services | 2021 |
| Cotswold VW Camper Hire Limited | Other services | 2019 |
| Cottage Trading Limited | Professional & scientific | 2015 |
| Country Car Vehicle Storage Ltd | Transport & logistics | 2023 |
| Countryside Planning Services Limited | Professional & scientific | 2001 |
| Countywide Developments Limited | Real estate | 1993 |
| Countywide Heathcote Limited | Real estate | 2007 |
| Countywide Molesey Limited | Real estate | 2000 |
| Court (the Charter) Birmingham Limited | Construction | 2017 |
| Court Close (Kineton) Management Co Ltd | Real estate | 2019 |
| Court IC Limited | Construction | 2018 |
| Coventry Money Centre Limited | Financial services | 2004 |
| Coventry Property Limited | Construction | 2017 |
| Covlink (UK) Limited | Information & communication | 1996 |
| Coxholmes Limited | Construction | 2017 |
| Coxley Kitchen Co. Ltd | Construction | 2007 |
| Coysh Digital Ltd | Information & communication | 2025 |
| CPM Accountancy 32282 Limited | Administrative & support | 2008 |
| CPM People (Employment) Limited | Professional & scientific | 2011 |
| CPM People (France) Ltd | Administrative & support | 2018 |
| CR Asset Management Ltd | Wholesale & retail | 2026 |