| Connecting for Talent Limited | Administrative & support | 2023 |
| Connection Counts Ltd | Education | 2025 |
| Connex Global Limited | Information & communication | 2020 |
| Consortium Group RF Limited | Professional & scientific | 2020 |
| Construction Marketing Experts Ltd | Professional & scientific | 2011 |
| Consult Experts in Finance Ltd | Professional & scientific | 2025 |
| Cooks Landscapes and Construction Limited | Construction | 2017 |
| Coolshock Events Limited | Manufacturing | 2009 |
| Coolshock Holdings Limited | Financial services | 2023 |
| Coope Ltd | Information & communication | 2012 |
| Cooper-Whyte Conservation Ltd. | Construction | 2020 |
| Coopers Rail and Civil Limited | Professional & scientific | 2017 |
| Copper Property Investments Limited | Construction | 2018 |
| Core Sanctuary Limited | Other services | 2025 |
| Cork Commercials Ltd | Wholesale & retail | 2014 |
| Corker Investments Limited | Financial services | 2011 |
| Cornerstone Build Projects Ltd | Construction | 2026 |
| Cornerstone Catering Midlands Ltd | Hospitality | 2022 |
| Cornerstone Developments Limited | Construction | 2025 |
| Cornfield Drive Owners Limited | Households | 2020 |
| Cornish Twist Limited | Hospitality | 2020 |
| Corporate Occasions Limited | Hospitality | 1989 |
| Corrymead Limited | Real estate | 2016 |
| Cossall Company Limited | Real estate | 2004 |
| Cosywarm Plumbing & Heating Limited | Construction | 2020 |
| Cosywarm Renovations Limited | Construction | 2025 |
| Coton House Farm Agricultural Limited | Agriculture & fishing | 2023 |
| Coton House Farm Events Limited | Hospitality | 2015 |
| Coton House Farm Stables Limited | Education | 2022 |
| Coton Lodge Events Limited | Hospitality | 2011 |
| Cotswold Developments (Nympsfield) Limited | Construction | 2020 |
| Cotswold Home Developments (Nympsfield) Limited | Construction | 2014 |
| Cotswold Property Auctions Limited | Real estate | 2023 |
| Cotswold Property Capital Limited | Real estate | 2017 |
| Coudrier Limited | Administrative & support | 2010 |
| Country Pursuits & Training Limited | Administrative & support | 2017 |
| Countrystore (Maidenhead) Limited | Wholesale & retail | 1994 |
| Courteney Toogood Limited | Hospitality | 2025 |
| Courtlands (Rothwell) Limited | Households | 2012 |
| Cowley Design Architects Ltd | Administrative & support | 2018 |
| COX and Sons Homes Limited | Construction | 2015 |
| CP Property Maintenance EM Ltd | Construction | 2021 |
| CP Rail Ltd | Construction | 2019 |
| CPC 1 Milton CT Ltd | Real estate | 2021 |
| Crab Clinical Informatics Ltd | Administrative & support | 2008 |
| Craddock Engineering Solutions Ltd | Professional & scientific | 2024 |
| Crafty Peewhit Limited | Construction | 2003 |
| Crave Leisure Limited | Hospitality | 2013 |
| Craveuk Ltd | Hospitality | 2018 |
| Create Psychology Services Ltd | Professional & scientific | 2017 |
| Creative Living Property Staging Ltd | Professional & scientific | 2026 |
| Cricketers Road Management Company Limited | Real estate | 2016 |
| Crisis Reaction Limited | Health & social care | 2025 |
| Cristal Care Limited | Health & social care | 2006 |
| Crooks Brothers Farms Limited | Agriculture & fishing | 2008 |
| Crosshairs Media Ltd | Professional & scientific | 2020 |
| Crownhill Homes Limited | Real estate | 2021 |
| Crownworks JQ Freehold Ltd | Construction | 2020 |
| Crownworks X Limited | Real estate | 2018 |
| Crump Property Group Limited | Real estate | 2026 |
| Crystal Tints Limited | Wholesale & retail | 2008 |
| CS & R Ltd | Professional & scientific | 2009 |
| CS Keogh & SON Limited | Construction | 2005 |
| CSS Europe Limited | Information & communication | 1996 |
| CTS Wholesale (Properties) Limited | Real estate | 2022 |
| Cumberland Clay Shooting Ground Ltd | Arts & recreation | 2018 |
| Cummins Financial Ltd | Financial services | 2016 |
| Cura Healthcare Solutions Ltd | Professional & scientific | 2024 |
| Curborough Barns Management Company Limited | Households | 2003 |
| Curborough Properties Limited | Real estate | 2020 |
| Curious Belly Ltd | Hospitality | 2025 |
| Curry Lichfield Limited | Hospitality | 2026 |
| Curtis Sport Ltd | Arts & recreation | 2014 |
| Cyber Bear Limited | Information & communication | 2006 |
| Cyber Onion Ltd | Information & communication | 2024 |
| Cyclic Holdings Ltd | Real estate | 2019 |
| D & C Consultancy (Midlands) Limited | Administrative & support | 2021 |
| D & J Medical Limited | Health & social care | 2025 |
| D & S (Mids) Ltd | Wholesale & retail | 2017 |
| D and D Textiles & Accessories Limited | Wholesale & retail | 2002 |
| D J Fieldhouse Limited | Professional & scientific | 2007 |
| D J Jones Plumbing and Heating Limited | Construction | 2013 |
| D M Thompson & SON (Agricultural Contractors ) Limited | Agriculture & fishing | 2005 |
| D Murphy Accountancy Limited | Professional & scientific | 2015 |
| D P James Limited | Construction | 2014 |
| D to D Deliveries Ltd | Transport & logistics | 2025 |
| D Westwood and Sons Limited | Real estate | 2019 |
| D White Trade and Transport Limited | Wholesale & retail | 2025 |
| D&D Carwash Ltd | Administrative & support | 2024 |
| D&O Property Management Limited | Households | 2025 |
| D'Hodge Holdings Limited | Financial services | 2023 |
| D. & P. Estates Limited | Real estate | 1940 |
| D.M.E. Tyres Limited | Water & waste | 2005 |
| D.O . Civil Engineering Solutions Ltd | Professional & scientific | 2021 |
| D3 Racetec Limited | Arts & recreation | 2014 |
| DA2AD Limited | Other services | 2021 |
| DAC01 (UK) Limited | Transport & logistics | 2018 |
| Daddio Limited | Real estate | 2022 |
| Daily Design Limited | Arts & recreation | 2014 |
| Dains Business Recovery Limited | Financial services | 2021 |