| Clearway Transformation Consultancy Limited | Professional & scientific | 2026 |
| Cleary Property Solutions Ltd | Real estate | 2024 |
| Clements and Church Limited | Wholesale & retail | 2007 |
| Clent View Exterior Cleaning Ltd | Administrative & support | 2021 |
| Clent View Resident Management Company Limited | Households | 2019 |
| Clerestory Advisory Ltd | Construction | 2023 |
| Clever Business Matters Ltd | Other services | 2021 |
| Clever Gecko Ltd | Professional & scientific | 2025 |
| Click and Keys Limited | Information & communication | 2025 |
| Clickbus Ltd | Transport & logistics | 2013 |
| Clifden Properties Limited | Real estate | 2019 |
| Clifton Investors Limited | Real estate | 2019 |
| Climate Heat and Cool Engineering Ltd | Construction | 2026 |
| Clinical Prescriptions Ltd | Health & social care | 2018 |
| Clinical Research Plus Ltd | Professional & scientific | 2021 |
| Clinikas Limited | Health & social care | 2019 |
| CLINIQ9 Ltd | Other services | 2020 |
| Cliniwise Ltd | Extraterritorial | 2025 |
| Cliveland Spinning Limited | Manufacturing | 2006 |
| Clivepoint Limited | Information & communication | 1988 |
| CLJ Homes and Developments Limited | Construction | 2024 |
| Clockland Limited | Real estate | 1981 |
| Clockland Properties Limited | Construction | 2018 |
| Clockwork Software Solutions Limited | Information & communication | 2016 |
| Cloisters (Leamington) Limited (the) | Households | 1971 |
| Cloontia Holdings Limited | Real estate | 2022 |
| Cloud 9 Digital Design Limited | Professional & scientific | 2000 |
| Cloud Buzz Ltd | Professional & scientific | 2025 |
| Cloud Chongers Ltd | Other services | 2016 |
| Cloud Experts Limited | Information & communication | 2017 |
| Cloud Kitchen One Limited | Hospitality | 2020 |
| Cloud Psychology Coaching & Consulting Ltd | Administrative & support | 2022 |
| Cloudbase Tech Ltd | Information & communication | 2023 |
| Cloudflow Limited | Information & communication | 2019 |
| Clouds END Training Limited | Education | 2020 |
| Cloudsend CIC | Health & social care | 2009 |
| Cloudwave Ltd | Information & communication | 2011 |
| Cloudworx Limited | Information & communication | 2018 |
| Cloves Foods Limited | Hospitality | 2015 |
| CLS Total Solutions Ltd | Administrative & support | 2014 |
| Club Cappuccino Limited | Hospitality | 2015 |
| Club Power Ltd | Wholesale & retail | 2017 |
| Club Triumph Limited | Other services | 2003 |
| CM (Strategic Growth Mentor) Limited | Professional & scientific | 2009 |
| CM Fitness Limited | Wholesale & retail | 2017 |
| CM Management Solutions Ltd | Construction | 2002 |
| CMA Development Solutions Ltd | Real estate | 2022 |
| CMB Medical Ltd | Health & social care | 2021 |
| CMB Plumbing & Heating Ltd | Construction | 2021 |
| CMC Imaging Services (Scanner) Limited | Administrative & support | 2019 |
| CMC Imaging Services Holdings Limited | Health & social care | 2019 |
| CMC Imaging Services Limited | Health & social care | 1998 |
| CMC Properties Holdings Limited | Financial services | 2024 |
| CMD Group of Services Ltd | Wholesale & retail | 2022 |
| CMH Ventures Limited | Construction | 2021 |
| Cmlw & Co. Holdings Ltd | Financial services | 2020 |
| CMS - HR Solutions Limited | Professional & scientific | 2009 |
| CMS AR Solutions Limited | Wholesale & retail | 2021 |
| CMS West Midlands Limited | Construction | 2025 |
| CMW Bar Enterprises Limited | Hospitality | 2017 |
| CMW Property Solutions Ltd | Real estate | 2025 |
| CNC Autos Limited | Manufacturing | 2013 |
| CNC Cases Ltd | Arts & recreation | 2010 |
| CNG Services Assets Ltd | Mining & quarrying | 2021 |
| CNG Services Group Ltd | Mining & quarrying | 2021 |
| CNG Services Ltd | Mining & quarrying | 2003 |
| Co-Active Consulting Ltd | Professional & scientific | 2024 |
| Coach House Cladding Limited | Construction | 2017 |
| Coach House Mews (Warwick) Residents Association Limited | Households | 2003 |
| Coaching and Consulting Ltd | Professional & scientific | 2016 |
| Coast Nest Limited | Hospitality | 2025 |
| Cobaco Holdings Limited | Professional & scientific | 2012 |
| Cobaco Limited | Professional & scientific | 2005 |
| Cobalt Lettings Ltd | Real estate | 2025 |
| Cobra Monitored Alert Ltd | Information & communication | 2020 |
| Cockaynes Consultancy Limited | Professional & scientific | 2024 |
| Coco ALI Limited | Other services | 2019 |
| Coco Property Limited | Real estate | 2016 |
| Cocojaxon Limited | Wholesale & retail | 2020 |
| Coda Construction Limited | Professional & scientific | 2001 |
| Codacom Limited | Administrative & support | 2015 |
| Code and Pixels Limited | Information & communication | 2013 |
| Code Klouds Ltd | Information & communication | 2022 |
| Code YOU Genetics Limited | Professional & scientific | 2017 |
| Codev Homes Limited | Construction | 1970 |
| Codex MIA Limited | Information & communication | 2025 |
| Codeze Limited | Administrative & support | 2023 |
| Coenseo Consulting Limited | Professional & scientific | 2016 |
| COF Limited | Wholesale & retail | 2025 |
| Coffee Roaster Online Ltd | Manufacturing | 2022 |
| Cogent Events Ltd | Administrative & support | 2014 |
| Cognition PPM Ltd | Construction | 2025 |
| Cognizant Business Logics Limited | Information & communication | 2015 |
| Cognizant Limited | Professional & scientific | 2012 |
| Cohart Contract Services Limited | Construction | 2015 |
| Cohesion Associates Limited | Real estate | 2019 |
| Cohesion Business Services Limited | Administrative & support | 2009 |
| Cohesion Communications Limited | Information & communication | 2016 |
| Cohesion Recruitment Limited | Information & communication | 2008 |
| Cold Bear Limited | Information & communication | 2013 |