| Clearflow Chemical Cleaning Ltd | Water & waste | 2018 |
| Clearview Landscapes Ltd | Administrative & support | 2023 |
| Clever Hare Digital Marketing Ltd | Professional & scientific | 2021 |
| Click for Cart Online Ltd | Wholesale & retail | 2026 |
| Click LAB Digital Ltd | Professional & scientific | 2021 |
| Clicksandcode Limited | Information & communication | 2025 |
| Clifford Saunt Homes Ltd | Real estate | 2022 |
| Clippys Limited | Professional & scientific | 2001 |
| Clockwork Insulation Limited | Construction | 2024 |
| Clockwork Screed Ltd | Construction | 2020 |
| Clockwork Underfloor Heating Ltd | Extraterritorial | 2023 |
| Cloisters Management (Northenden) Limited | Professional & scientific | 1992 |
| Close Leasing Limited | Financial services | 2007 |
| Closomat (Great Britain) Limited | Manufacturing | 1962 |
| Closomat Care Limited | Professional & scientific | 1989 |
| Closomat Hygiene Services Limited | Professional & scientific | 1989 |
| Closomat Limited | Wholesale & retail | 1990 |
| Cloud & Fibre Ltd | Information & communication | 2014 |
| Cloud Facilities Services Group Limited | Administrative & support | 2015 |
| Cloud Property Maintenance Limited | Administrative & support | 2017 |
| Cloverfield Cattery Limited | Other services | 2025 |
| Clrd Ltd | Professional & scientific | 2019 |
| CLS Hair Studio Limited | Other services | 2021 |
| Clsk Services Limited | Administrative & support | 2024 |
| Clubplates Limited | Arts & recreation | 2011 |
| Cmonty Ltd | Information & communication | 2020 |
| CMP Tech Consulting Limited | Information & communication | 2026 |
| CNG Property Limited | Real estate | 2020 |
| Coaching Values Ltd. | Professional & scientific | 2019 |
| Coarse to Fine Coffee Limited | Hospitality | 2026 |
| Coatings Plus Limited | Construction | 2019 |
| Cobbled Lane Developments Limited | Construction | 2015 |
| COC Engineering Limited | Mining & quarrying | 2024 |
| Code Pixels Ltd | Information & communication | 2008 |
| Code Property Management Ltd | Households | 2021 |
| Codrophenia GX Limited | Hospitality | 2018 |
| Cognomedia Ltd | Information & communication | 2025 |
| Cognoscenti International Limited | Information & communication | 1990 |
| Cognotherapy Limited | Information & communication | 2024 |
| Collinsford Flooring Ltd | Wholesale & retail | 2024 |
| Collosys Limited | Professional & scientific | 2021 |
| Colour Green Landscape Architects Limited | Professional & scientific | 2022 |
| Colour Pvc-U Limited | Construction | 2006 |
| Columbo Testing Services Ltd | Information & communication | 2011 |
| Comedy Simulation Ltd | Information & communication | 2025 |
| Comer Electrical Limited | Construction | 2015 |
| Commercial Choice Property Maintenance Ltd | Construction | 2020 |
| Commercial Costs Limited | Professional & scientific | 2019 |
| Commercial Extractions Nationwide Ltd | Wholesale & retail | 2018 |
| Commercial Inspirations Limited | Professional & scientific | 2004 |
| Commercial Marketing Services Limited | Wholesale & retail | 2021 |
| Community Action Group Ltd | Public administration | 2025 |
| Company Mobiles.Com Ltd | Information & communication | 2012 |
| Compass Investments and Holdings Ltd | Financial services | 2025 |
| Complete 2 Financial Solutions Ltd | Financial services | 2023 |
| Complete Heat, Plumbing and Cooling Ltd | Construction | 2025 |
| Complete Joinery Solutions Limited | Construction | 2018 |
| Composite Roof Supplies Ltd | Wholesale & retail | 2017 |
| Comprehensive Building Consultancy Ltd | Construction | 2012 |
| Con-Tec Holdings Ltd | Financial services | 2025 |
| Con-Tec Property Services Ltd | Real estate | 2016 |
| Concours Refinishing Limited | Wholesale & retail | 2018 |
| Confident Construction Ltd | Construction | 2014 |
| Confido Solutions Ltd | Information & communication | 2021 |
| Conique Limited | Wholesale & retail | 2023 |
| Connectcases Limited | Information & communication | 2017 |
| Connected Buildings Limited | Construction | 2018 |
| Connections the Recruitment Specialists Limited | Administrative & support | 2014 |
| Connor Tarry Limited | Administrative & support | 2025 |
| Conserta Limited | Professional & scientific | 2024 |
| Constarlation Ltd | Professional & scientific | 2023 |
| Consulte Limited | Administrative & support | 2014 |
| Control Recruitment Solutions Ltd | Administrative & support | 2022 |
| Conv Limited | Health & social care | 2013 |
| Conversion Holdings Limited | Professional & scientific | 2000 |
| Convertify Visitors Ltd | Information & communication | 2024 |
| Copper Beeches Day Nursery Limited | Health & social care | 2006 |
| Corallista Ltd | Professional & scientific | 2021 |
| Core Electrical Consultants Limited | Professional & scientific | 2014 |
| Core Mechanical Solutions Limited | Administrative & support | 2019 |
| Core Providers Ltd | Information & communication | 2015 |
| Coreen Barker Accountancy Ltd | Professional & scientific | 2017 |
| Cork of the North (HM) Limited | Wholesale & retail | 2018 |
| Cork of the North Limited | Wholesale & retail | 2012 |
| Corner CUP Limited | Hospitality | 2018 |
| Cornerstone Property Surveyors (NW) Ltd | Professional & scientific | 2024 |
| Cornproductions Ltd | Wholesale & retail | 2021 |
| Cornwall Calling Limited | Hospitality | 2024 |
| Corporate Options Review Limited | Professional & scientific | 2000 |
| Corporate Recruitment Solutions Limited | Administrative & support | 2001 |
| Cortroom Consulting Ltd | Information & communication | 2024 |
| COS Luxe Ltd | Wholesale & retail | 2018 |
| Cosada Ltd | Professional & scientific | 2024 |
| Cossis Consultancy Limited | Professional & scientific | 2022 |
| Costings and Management Limited | Professional & scientific | 2024 |
| Cotton to Code Limited | Information & communication | 2024 |
| Cove Leisure Limited | Wholesale & retail | 2023 |
| CPF Solutions Limited | Professional & scientific | 2013 |
| CR Wealth Global IT Ltd | Information & communication | 2025 |
| CR01 Property Investments Limited | Real estate | 2025 |