| Classical Beauty Ltd | Extraterritorial | 2017 |
| Clayton & Larkin Ltd | Real estate | 2020 |
| Cleaco Limited | Professional & scientific | 2020 |
| Clear View Web Design Limited | Information & communication | 2007 |
| Clearance With Care Ltd | Water & waste | 2020 |
| Clearwater Editorial Limited | Administrative & support | 2025 |
| Clement House Management Limited | Households | 2004 |
| Clements Close Management Limited | Households | 2003 |
| Clinterval Coaching Limited | Other services | 2017 |
| Clinton Garage Limited | Wholesale & retail | 2012 |
| Clivatex Co., Ltd. | Administrative & support | 2018 |
| CLN Solicitors Ltd | Professional & scientific | 2022 |
| Cloth Atelier Limited | Wholesale & retail | 1994 |
| Cloudtop Industry Co., Ltd | Extraterritorial | 2018 |
| CLW Group Ltd | Extraterritorial | 2018 |
| CMC International (UK) Limited | Professional & scientific | 2002 |
| CMG Automotive Limited | Wholesale & retail | 2017 |
| CMX Industry Co., Ltd | Extraterritorial | 2021 |
| Cncclipart Ltd | Information & communication | 2020 |
| Cobalt Electrics Limited | Construction | 2022 |
| Cockell Building Services Ltd | Construction | 2012 |
| Cognitech Solutions Limited | Information & communication | 2010 |
| Colin & Co Management Unlimited | Administrative & support | 2017 |
| Colin & Co Property Management Limited | Real estate | 2017 |
| Colo Industrial Co., Limited | Administrative & support | 2009 |
| Colorful Horizon UK Limited | Wholesale & retail | 2021 |
| Colour Flash Ltd | Wholesale & retail | 2011 |
| Colour ME UP Limited | Real estate | 1997 |
| Colton Safety Management Services Ltd | Administrative & support | 2018 |
| Comclark Solutions Limited | Professional & scientific | 2012 |
| Comedy at Work Ltd | Arts & recreation | 2019 |
| Comings International Trading Co., Limited | Wholesale & retail | 2021 |
| Comitto Ltd | Information & communication | 2013 |
| Commercial Boiler Services Ltd | Manufacturing | 2012 |
| Common Lane Developments Limited | Construction | 2011 |
| Common Sense HR Consulting Ltd | Administrative & support | 2019 |
| Commsphere Limited | Information & communication | 2025 |
| Communify E-Business Solutions Ltd | Wholesale & retail | 2010 |
| Complete Accounts Limited | Professional & scientific | 1999 |
| Complete Landscapes and Driveways Limited | Construction | 2009 |
| Complete Payroll (Kenilworth) Limited | Professional & scientific | 2014 |
| Complete Spreadsheet Solutions Ltd | Information & communication | 2006 |
| Computer Controlled Solutions Limited | Manufacturing | 1996 |
| Conatus Health Limited | Administrative & support | 2010 |
| Concessions UK Limited | Extraterritorial | 2007 |
| Concordant Ltd | Administrative & support | 2014 |
| Confianza Advisory Limited | Professional & scientific | 2019 |
| Connect 2 the Future Ltd | Education | 2023 |
| Connect Staff Ltd | Administrative & support | 2017 |
| Connection Momentum Ltd | Administrative & support | 2026 |
| Connor Carson Ltd | Professional & scientific | 2022 |
| Consilio Limited | Professional & scientific | 2000 |
| Consulting Allies Limited | Professional & scientific | 2014 |
| Continental Industrie UK Limited | Administrative & support | 2013 |
| Contract Managers UK Limited | Professional & scientific | 2023 |
| Contract Skips Ltd | Construction | 2014 |
| Conventus Limited | Professional & scientific | 2001 |
| Conversioncraft Ltd | Professional & scientific | 2025 |
| Cooper Aviation Training Limited | Education | 2017 |
| Cooper Group Holdings Limited | Financial services | 2020 |
| Cooper Handling Solutions Limited | Administrative & support | 2013 |
| Cooper Specialised Handling Limited | Wholesale & retail | 2005 |
| Copybyliz Ltd | Professional & scientific | 2010 |
| Corkskrew Applications Limited | Information & communication | 2025 |
| Cornwall NFU Company Limited | Professional & scientific | 2013 |
| Cosmic Zoom Limited | Administrative & support | 2014 |
| Cosmicsoft Ltd | Information & communication | 2008 |
| Cosy Home Dog Boarding Ltd | Other services | 2026 |
| Cotswell Capital Limited | Construction | 2025 |
| Cotterrell Auto Services Ltd | Wholesale & retail | 2018 |
| Coventis Corporate Services Ltd | Extraterritorial | 2007 |
| Coventrian Homes Ltd | Hospitality | 2019 |
| Coventry Drainage Ltd | Other services | 2023 |
| Coventry Tornadoes Basketball Club Ltd | Arts & recreation | 2026 |
| CPM Tech Ltd | Information & communication | 2026 |
| CR7 Racing Trade Ltd | Wholesale & retail | 2024 |
| Crackley Garage Limited | Manufacturing | 2010 |
| Crag Trading Limited | Administrative & support | 2026 |
| Crazy Kiln Pottery Limited | Manufacturing | 2018 |
| Creative Trading Limited | Administrative & support | 2023 |
| Creative Life Trading Co., Ltd | Extraterritorial | 2024 |
| Creative Sign & Design Limited | Professional & scientific | 2002 |
| Creative Team Building Ltd | Other services | 2023 |
| Crebro Consulting Limited | Information & communication | 2014 |
| Credesco Limited | Professional & scientific | 2013 |
| Credible Design Limited | Administrative & support | 2009 |
| Crema Lafon Co., Ltd | Administrative & support | 2017 |
| Cress Consultancy Limited | Professional & scientific | 2014 |
| Crestwood Investments (Midlands) Limited | Extraterritorial | 1963 |
| Critgas Ltd | Health & social care | 2023 |
| Crocstar Media Limited | Information & communication | 2007 |
| Cromwell Electrical Services Ltd | Administrative & support | 2005 |
| Cross Point Development Partnership LLP | | 2026 |
| Crow Management Solutions (U.K.) Limited | Professional & scientific | 2008 |
| Crown Auto Components Ltd | Manufacturing | 2024 |
| Crown Creators Limited | Administrative & support | 2025 |
| CRT Compliance Testing Service Co., Ltd | Extraterritorial | 2017 |
| Cryfield Consulting Ltd | Professional & scientific | 2015 |
| CS Display Co., Ltd | Extraterritorial | 2018 |
| CSK Group Ltd | Financial services | 2021 |