| Coopers Gourmet Foods Limited | Manufacturing | 1991 |
| Copeland Healthcare Limited | Health & social care | 2014 |
| Copeland Residence Ltd | Real estate | 2021 |
| Copperweld Bimetallics UK Limited | Manufacturing | 1998 |
| Corb Investments Limited | Real estate | 2019 |
| Corb Limited | Construction | 2014 |
| Corb Projects Ltd | Construction | 2021 |
| Core Digital Services Limited | Information & communication | 2025 |
| Core Technologies (Telford) Limited | Manufacturing | 2019 |
| Corley Plant Limited | Construction | 2000 |
| Cornerstone LOG Ltd | Transport & logistics | 2019 |
| Corp Energy Limited | Construction | 2022 |
| Corporate Axis Limited | Professional & scientific | 2007 |
| Corprolet Properties Ltd | Real estate | 2020 |
| Corroconsult Services UK Ltd | Professional & scientific | 2015 |
| Corroconsult UK Limited | Professional & scientific | 2006 |
| Corrosion Control Services Limited | Construction | 1989 |
| Cortes Business Management Ltd | Professional & scientific | 2025 |
| Cosford Caravans & Motorhomes Limited | Wholesale & retail | 1983 |
| Cosford Caravans Limited | Wholesale & retail | 2007 |
| Cosgrove & Cosgrove Limited | Professional & scientific | 2003 |
| Cosium UK Limited | Wholesale & retail | 2018 |
| Costin Oprea Ltd | Transport & logistics | 2016 |
| Cosy Cottage Childcare Limited | Education | 2021 |
| Cotwall Farm Limited | Agriculture & fishing | 2013 |
| Cound Lake Properties Limited | Real estate | 2015 |
| Country Gardens Maintenance Ltd. | Administrative & support | 2008 |
| Countrywide Electrical Installation Ltd | Construction | 2023 |
| County Star Limited | Other services | 2019 |
| Course Beetle Ltd | Extraterritorial | 2015 |
| Court Autos Limited | Wholesale & retail | 2003 |
| Court Street Collections Limited | Administrative & support | 2020 |
| Courtney Downing Estates Limited | Real estate | 2018 |
| Cousins & Co Project Ltd | Construction | 2024 |
| Couture Lounge Ltd | Other services | 2022 |
| Covenant Crest Group Ltd | Transport & logistics | 2025 |
| Coventry Grill Ltd | Hospitality | 2019 |
| COW Pasture Energy Limited | Energy | 2014 |
| Cpcore Ltd | Wholesale & retail | 2023 |
| CQ Driveways & Patios Ltd | Administrative & support | 2025 |
| CQS Solutions Limited | Professional & scientific | 2007 |
| Craemer UK Limited | Manufacturing | 1991 |
| Craig Michael Maintenance Ltd | Manufacturing | 2015 |
| Cranmore Fish Bar Ltd | Hospitality | 2019 |
| Cranoss Ltd | Households | 2025 |
| Crash Care Ltd | Wholesale & retail | 2024 |
| Craven Motor Sport Ltd | Extraterritorial | 2025 |
| Craven Sisters Ltd | Real estate | 2023 |
| Crazy Unicorn Brews Ltd | Hospitality | 2023 |
| CRB Property Investment Group Ltd | Real estate | 2025 |
| CRC Emea Limited | Hospitality | 2014 |
| Creating Innovation Ltd | Manufacturing | 2024 |
| Creative Box Limited | Construction | 2023 |
| Creative Building Solutions Ltd | Administrative & support | 2026 |
| Creative Client Services Limited | Financial services | 2015 |
| Creative Pension Planning Limited | Financial services | 2012 |
| Creator Accounting Ltd | Professional & scientific | 2025 |
| Creatorkit Ltd | Wholesale & retail | 2025 |
| Crescent Farm Livery Limited | Agriculture & fishing | 2016 |
| Crestleigh Homes Ltd | Real estate | 2019 |
| Crew Consultancy Group Limited | Professional & scientific | 2019 |
| Crhr Limited | Professional & scientific | 2016 |
| Cristinel 94 Ltd | Construction | 2025 |
| Croft & Oakes Financial Planners Limited | Financial services | 2015 |
| Crompton Instruments Limited | Professional & scientific | 1965 |
| Crompton Parkinson Limited | Professional & scientific | 1913 |
| Crop Spraying Services Limited | Agriculture & fishing | 2012 |
| Crown Plus Holdings Limited | Financial services | 2025 |
| Crown Plus Limited | Construction | 2015 |
| Crown Print&Design Ltd | Manufacturing | 2021 |
| Crowson Homes Limited | Real estate | 2025 |
| Crowson Plumbing & Heating Limited | Construction | 2024 |
| CRU Technologies Limited | Information & communication | 2011 |
| Cryogenetics Limited | Agriculture & fishing | 2012 |
| Cryotainar B.V Limited | Wholesale & retail | 2025 |
| CS Automation (Telford) Limited | Extraterritorial | 2020 |
| CS Business Connexions Limited | Extraterritorial | 2022 |
| CS Company Restorations (UK) Limited | Extraterritorial | 2024 |
| CS Home Energy Limited | Wholesale & retail | 2025 |
| CS Jones Building Solutions Ltd | Construction | 2019 |
| CS Legal Wills & Probate Limited | Extraterritorial | 2025 |
| CSD Brands Limited | Wholesale & retail | 2026 |
| CSD Property & Holdings Limited | Real estate | 2018 |
| CSG Valves Limited | Manufacturing | 2015 |
| CSK Home Care Ltd | Health & social care | 2024 |
| CST Professional Painting & Decorating Limited | Construction | 2023 |
| Csts Limited | Professional & scientific | 2006 |
| CT Land & Marine Engineering Services Ltd | Professional & scientific | 2015 |
| CTA Safety Ltd | Construction | 2023 |
| CTC Residential Limited | Real estate | 2023 |
| CTC Training and Development Limited | Education | 2012 |
| Ctezo Limited | Construction | 2021 |
| CTR Commercials Limited | Wholesale & retail | 2018 |
| CTR Construction Limited | Construction | 2025 |
| Ctrl Plus Dynamics Limited | Professional & scientific | 2025 |
| CUI & Co Trading Limited | Wholesale & retail | 2012 |
| Cultivate Properties Ltd | Real estate | 2026 |
| Culturekind Chinese Community CIC | Education | 2026 |
| Culturo Limited | Information & communication | 2025 |
| CUP & Chapter Limited | Wholesale & retail | 2026 |