| Clark Young & Co Limited | Professional & scientific | 2012 |
| Clarke Brothers (Expo) Limited | Administrative & support | 2014 |
| Clarkson Osborn International Limited | Extraterritorial | 2001 |
| Clasm Ltd | Construction | 2024 |
| Class Communications Limited | Information & communication | 2021 |
| Classic Fork Truck Holdings Limited | Financial services | 2026 |
| Classic Fork Trucks (Hire) Limited | Administrative & support | 1988 |
| Classic Fork Trucks Limited | Manufacturing | 2017 |
| Classic India Limited | Wholesale & retail | 1994 |
| Clatas Limited | Professional & scientific | 2022 |
| Claudio Trans Ltd | Transport & logistics | 2018 |
| Clay Group Property Limited | Real estate | 2020 |
| Claymarshhouse Ltd | Real estate | 2019 |
| CLB Contracting Ltd | Wholesale & retail | 2025 |
| CLB Group Holdings Ltd | Real estate | 2016 |
| Cldm Interiors Limited | Construction | 2022 |
| Cleanit Contract Services Limited | Administrative & support | 2003 |
| Clear Concept Interiors Limited | Construction | 2024 |
| Clear CUT Floor Coverings Ltd | Wholesale & retail | 2014 |
| Clearconnect Solutions Ltd | Administrative & support | 2026 |
| Clearhills Estates Ltd | Real estate | 2026 |
| Clearhills Limited | Other services | 2025 |
| Clearmotion (UK) Ltd. | Professional & scientific | 2017 |
| Clearmotion International Holdings Ltd | Financial services | 2023 |
| Clearpath Revenue Consulting Limited | Professional & scientific | 2026 |
| Clearpine Developments Limited | Arts & recreation | 1989 |
| Clearsky Roofing & Building Ltd | Construction | 2025 |
| Clearstone Property Services Ltd | Water & waste | 2026 |
| Cleary & Sons Driveways & Landscaping Ltd | Administrative & support | 2026 |
| Cleaver Consulting Services Limited | Professional & scientific | 2015 |
| Cleaver Squash Limited | Arts & recreation | 1978 |
| Clement Safety Limited | Other services | 2022 |
| Clementine Investments Ltd | Real estate | 2024 |
| Clever Coaching UK Ltd | Education | 2021 |
| Clibow Ltd | Construction | 2019 |
| Click Express Limited | Wholesale & retail | 2013 |
| Clientell Limited | Professional & scientific | 2022 |
| Clinic AI Ltd | Information & communication | 2024 |
| Clinical Claims Limited | Other services | 2011 |
| Clive Fear Associates | | 1991 |
| Clued UP Accounting Ltd | Professional & scientific | 2023 |
| Clutch Brake & Autospares Limited | Professional & scientific | 2001 |
| CM and MJ Holdings Limited | Real estate | 2023 |
| CM Assessing Ltd | Health & social care | 2026 |
| CM Beauty Studio Ltd | Other services | 2025 |
| CMB Haulage Ltd | Transport & logistics | 2025 |
| CMP Universal Enterprises Ltd | Wholesale & retail | 2025 |
| Co Remote Care Ltd | Administrative & support | 2023 |
| Coachbuilt Accessible Vehicles Limited | Wholesale & retail | 2013 |
| Coachbuilt Engineering Ltd | Wholesale & retail | 2022 |
| Coachbuilt GB Ltd | Manufacturing | 2009 |
| Cocoluxe Ltd | Manufacturing | 2023 |
| CODEFORM3D Ltd | Professional & scientific | 2026 |
| Cofa Civil Engineering Ltd | Construction | 2019 |
| Cofa Developments Ltd | Real estate | 2021 |
| Cofastre Pets Hotel Limited | Professional & scientific | 2006 |
| Coffee & Ice Cream Co Ltd | Hospitality | 2023 |
| Coffee DA Vinci Ltd | Wholesale & retail | 2025 |
| Cognition Psychology Ltd | Education | 2023 |
| Cognitive Edge Services Ltd | Information & communication | 2026 |
| Cogsdill-Nuneaton, Limited | Manufacturing | 1961 |
| Cojo 4 Limited | Other services | 2020 |
| Colin Estates Limited | Real estate | 2025 |
| Collective Agri Construction Limited | Construction | 2017 |
| Collier-Hodgkinson Limited | Real estate | 1983 |
| Comash Holdings Ltd | Financial services | 2021 |
| Comiskey Heating Limited | Wholesale & retail | 1965 |
| Commercial Transport Solutions Limited | Transport & logistics | 2024 |
| Committed Software Limited | Information & communication | 2015 |
| Community Development Initiatives Today CIC | Education | 2024 |
| Community Franchise Limited | Administrative & support | 2006 |
| Community Furniture Hub C.I.C. | Wholesale & retail | 2026 |
| Community of Christ | Other services | 2001 |
| Compass Advisories Limited | Professional & scientific | 2026 |
| Compass Geotechnical Limited | Professional & scientific | 1993 |
| Compassionate Care for YOU Ltd | Health & social care | 2020 |
| Complexus Limited | Information & communication | 2001 |
| Compliancecare Ltd | Public administration | 2023 |
| Comtel Technical Services Ltd | Information & communication | 2022 |
| Concentric Group Ltd | Health & social care | 2020 |
| Concept 1 Carbon Limited | Wholesale & retail | 2015 |
| Concepts Fashion Limited | Wholesale & retail | 2018 |
| Concepts Haus Ltd | Wholesale & retail | 2020 |
| Confident Solutions Ltd | Information & communication | 2026 |
| Congerstone Kickstart CIC | Administrative & support | 2016 |
| Coniston Court (Nuneaton) Limited | Households | 1974 |
| Connect Ceilings & Partitions Ltd | Construction | 2021 |
| Conscious Leadership Academy Ltd | Administrative & support | 2023 |
| Consilio Strategic Consultancy Ltd | Professional & scientific | 2019 |
| Constellation Designs Ltd | Professional & scientific | 1997 |
| Consultarian Ltd | Information & communication | 2022 |
| Content Care Ltd | Health & social care | 2006 |
| Contingent IT Limited | Information & communication | 2013 |
| Contract Scaffolding Midlands Limited | Construction | 2016 |
| Contrast Assist Ltd | Professional & scientific | 2014 |
| Convenant Success Limited | Information & communication | 2014 |
| Cookra Limited | Other services | 2014 |
| Cooks Catering & Baking Limited | Manufacturing | 2019 |
| COP Angel Ltd | Wholesale & retail | 2022 |
| Copes Produce Ltd | Wholesale & retail | 2024 |