| Content Property Limited | Real estate | 2022 |
| Contestus UK Ltd | Construction | 2021 |
| Continental Foods Gloucester Limited | Wholesale & retail | 2007 |
| Continental Inspection Co. (UK) Ltd | Transport & logistics | 2011 |
| Contour Estates Limited | Real estate | 1997 |
| Contract & Commercial Solutions Limited | Construction | 2008 |
| Contract Management Solutions Consultancy Limited | Professional & scientific | 2011 |
| Control Zone Consulting Ltd | Information & communication | 2023 |
| Convenience Studley Ltd | Wholesale & retail | 2019 |
| Convergence Group (Wireless) Networks Limited | Information & communication | 2003 |
| Cookie Box Creations Ltd | Manufacturing | 2022 |
| Cookie Crush Limited | Hospitality | 2020 |
| Cooking APE UK Ltd | Hospitality | 2015 |
| COOKING4YOU Ltd | Administrative & support | 2016 |
| Cool Horses Management Limited | Administrative & support | 2022 |
| Cool Movers Limited | Information & communication | 1999 |
| Coombs Residential Ltd | Other services | 2013 |
| Cooper Holdings Group Limited | Water & waste | 2019 |
| Cooper Securities (Dudley) Limited | Professional & scientific | 1913 |
| Cooper Securities Limited | Professional & scientific | 1976 |
| Cooper Specialist Groundworks Ltd | Water & waste | 2016 |
| Coopers Law Ltd | Professional & scientific | 2021 |
| Coopers Troopers Fitness Ltd | Arts & recreation | 2021 |
| Copes Electrical Limited | Construction | 2014 |
| Copper Beeches (Solihull) Limited | Households | 1989 |
| Coppertree Limited | Construction | 2017 |
| Coppice Close Residents' Association Limited | Households | 1981 |
| Coppice Enterprises Ltd | Transport & logistics | 2013 |
| Coppice Side Company Ltd | Construction | 2023 |
| Copt Heath Consulting Ltd | Administrative & support | 2022 |
| Copt Heath Investment Partners Limited | Real estate | 2013 |
| Cordelle Investments Ltd | Financial services | 2022 |
| Cordelle Precision Engineering Limited | Manufacturing | 2007 |
| Core Wiring Solutions Limited | Other services | 2016 |
| Corelec Ltd | Construction | 2022 |
| Corepax Holdings Ltd | Financial services | 2025 |
| Corevac Ltd | Construction | 2026 |
| Corner Basket Ltd | Wholesale & retail | 2025 |
| Corner Oak Property Partnership Limited | Administrative & support | 2018 |
| Cornerstone Abodes Limited | Real estate | 2024 |
| Cornerstone Brickwork Limited | Construction | 2014 |
| Cornerstone Construction Consultancy Services Limited | Professional & scientific | 2014 |
| Cornerstone Driveways & Landscapes Ltd | Construction | 2026 |
| Cornerstone Property Consultantancy Ltd | Real estate | 2026 |
| Cornucopia (Solihull) Limited | Wholesale & retail | 2010 |
| Cornwhist Limited | Hospitality | 1991 |
| Cornyx Lane Motor Company Ltd | Wholesale & retail | 2026 |
| Coronary Solutions Ltd | Health & social care | 2015 |
| Corporate Clothing Company (UK) Limited | Manufacturing | 1999 |
| Corporate Source Ltd | Professional & scientific | 2015 |
| Correla Limited | Administrative & support | 2020 |
| Corsair Property Solutions Ltd | Real estate | 2021 |
| Cosmic Trader Ltd | Wholesale & retail | 2024 |
| Cosmin Solution Ltd | Professional & scientific | 2022 |
| Cosmo Estates Ltd | Real estate | 2017 |
| Cosmo Properties Ltd | Real estate | 2024 |
| Cosmo Students Ltd | Real estate | 2016 |
| Costclo Limited | Hospitality | 2022 |
| Costello Holdings Limited | Real estate | 2022 |
| Cosy Heating & Plumbing Ltd | Construction | 2019 |
| Cosy Knight Ltd | Wholesale & retail | 2025 |
| Cosy Sleep Rooms Ltd | Real estate | 2025 |
| Cotality U.K. Limited | Information & communication | 2005 |
| Coton Financial Management Limited | Financial services | 2002 |
| Cotsford (Management) Limited | Households | 2004 |
| Cotswold Homes Group Limited | Real estate | 2021 |
| Cotswold Homes Trading Limited | Hospitality | 2021 |
| Cotswold Photographers Limited | Professional & scientific | 2022 |
| Cotswold Springs Limited | Construction | 2017 |
| Cotwel Ltd | Professional & scientific | 2025 |
| Couch Perry & Wilkes (Acoustics) Limited | Professional & scientific | 2021 |
| Couch Perry & Wilkes Environmental LLP | | 2011 |
| Couch Perry & Wilkes LLP | | 2006 |
| Couch Perry Wilkes East Midlands LLP | | 2012 |
| Couchperrywilkes Support Limited | Financial services | 2016 |
| Cougar Construction Limited | Construction | 2007 |
| Coulter Action Limited | Information & communication | 2013 |
| Country Butchers Limited | Wholesale & retail | 2004 |
| Countrylivinglodges Limited | Hospitality | 2019 |
| Countrypark Properties Limited | Construction | 2002 |
| Countrywide Project Management Limited | Real estate | 2008 |
| Countrywide Property Investments Limited | Real estate | 2005 |
| County Garage (Birmingham) Limited | Wholesale & retail | 1959 |
| Countywide Property Holdings Limited | Real estate | 2011 |
| Courierpals Limited | Transport & logistics | 2024 |
| Coursecount Limited | Construction | 2026 |
| Courtyard Management (Sutton Coldfield) Limited | Real estate | 1995 |
| Courtyard Projects Limited | Professional & scientific | 1998 |
| Couture Brows & Cosmetics Limited | Health & social care | 2017 |
| Couture Clinic Group Limited | Health & social care | 2024 |
| Cove Care Children's Services Limited | Health & social care | 2026 |
| Cove HR Consultancy Ltd | Administrative & support | 2018 |
| Coventry and Warwickshire Diagnostic Services Limited | Health & social care | 2008 |
| Coventry Developments Limited | Real estate | 2004 |
| Coventry Orthodontics Limited | Health & social care | 2022 |
| Covered in Love Ltd | Other services | 2017 |
| Covertech Limited | Information & communication | 2019 |
| COX Cooper Limited | Professional & scientific | 2007 |
| COY Build Ltd | Construction | 2025 |
| Cozy Houses Ltd | Real estate | 2021 |