| Complete 360 Ltd | Professional & scientific | 2023 |
| Complete Building Renovations Ltd | Construction | 2023 |
| Complete Business Utilities Limited | Wholesale & retail | 2018 |
| Complete Communications Staffordshire Limited | Information & communication | 2023 |
| Complete ICT Solutions (Shropshire) Limited | Information & communication | 2014 |
| Complete ICT Solutions Limited | Information & communication | 2010 |
| Complete Voice & Data Solutions Ltd | Information & communication | 2019 |
| Comuser Limited | Other services | 1999 |
| Confetti Limited | Wholesale & retail | 1995 |
| Connoisseur Auction Consultants Limited | Wholesale & retail | 2016 |
| Connoisseur Auction's Limited | Wholesale & retail | 2021 |
| Conservation Solutions Limited | Construction | 1998 |
| Consulmed Limited | Health & social care | 2022 |
| Containment Quality Associates Limited | Professional & scientific | 1993 |
| Contaservtm Ltd | Transport & logistics | 2018 |
| Contrac Electrical Ltd | Construction | 2025 |
| Contract Seating (UK) Limited | Other services | 2002 |
| Convergence Computing Ltd | Professional & scientific | 2026 |
| Cool Movers Logistics Ltd | Transport & logistics | 2021 |
| Coolbase Refrigeration and Air Conditioning Ltd | Construction | 2026 |
| Copeland & Craddock Limited | Manufacturing | 1966 |
| Coppergrove Properties Limited | Administrative & support | 2016 |
| Copyright (U.K.) Limited | | 1986 |
| Corare Ltd | Information & communication | 2025 |
| Cord Electrics Ltd | Construction | 2024 |
| Core Accessories Ltd | Wholesale & retail | 2023 |
| Core Mvmnt LLP | | 2019 |
| Coredata Consultancy Ltd | Information & communication | 2023 |
| Corinne Wainwright Limited | Professional & scientific | 2003 |
| Cormeen Limited | Hospitality | 2025 |
| Cornwell's Chemists Limited | Wholesale & retail | 1939 |
| Cost Consultancy & Quantity Surveying Services Limited | Construction | 2023 |
| Costal Site Services Ltd | Construction | 2024 |
| Costride Ltd | Information & communication | 2026 |
| Cotton and Heath Limited | | 1965 |
| Cound Park Residents Limited | Households | 2005 |
| Counselling and Hypnotherapy North East Limited | Health & social care | 2025 |
| Count-Up Limited | Administrative & support | 2000 |
| Country Grounds Service Ltd | Administrative & support | 2011 |
| Coupe Investments Limited | Real estate | 2003 |
| Coutts Meat Processing Ltd | Manufacturing | 2021 |
| Covent Garden Creations Ltd | Hospitality | 2024 |
| Cowleigh Design Limited | Professional & scientific | 2004 |
| Cozworth Properties Ltd | Real estate | 2020 |
| Cozworth Real Estate Ltd | Households | 2021 |
| CPD Surveying Ltd | Professional & scientific | 2015 |
| CPE Group Limited | Information & communication | 2017 |
| CPK Lettings Limited | Real estate | 2019 |
| Cpot Ltd | Wholesale & retail | 2026 |
| CQV Consultants Limited | Administrative & support | 2016 |
| CQV Solutions Limited | Administrative & support | 2018 |
| Craft Time Workshop Limited | Education | 2025 |
| Crafted Kindle Ltd | Arts & recreation | 2025 |
| Craig Stott Installations Limited | Construction | 2014 |
| CRE8 Medical Limited | Professional & scientific | 2007 |
| CRE8 Medical Trustee Limited | Professional & scientific | 2024 |
| Creative First Limited | Information & communication | 2008 |
| Creatorlens Analytics Ltd | Information & communication | 2026 |
| Crepz Club Fashion Store Ltd | Wholesale & retail | 2023 |
| Crepz Collective Ltd | Wholesale & retail | 2025 |
| Creste Property Limited | Real estate | 2025 |
| Cretu Transport Limited | Transport & logistics | 2016 |
| Crewe Orlando (UK) Limited | Wholesale & retail | 2016 |
| Crisis Network Solutions Ltd | Professional & scientific | 2024 |
| Critchlow Contracting Ltd | Construction | 2024 |
| Critical Systems Management Ltd | Manufacturing | 2022 |
| Crleemanagement Ltd | Information & communication | 2025 |
| CRM Building Solutions Ltd | Construction | 2025 |
| Croak IT Ltd | Real estate | 2017 |
| Croft Nursery School Limited | Education | 1990 |
| Crofters Court Ltd | Real estate | 2026 |
| Crofton Supermarket and PO Limited | Wholesale & retail | 2011 |
| Cromwell Wilkes Ltd | Professional & scientific | 2013 |
| Cronshaw Property Management Ltd | Real estate | 2025 |
| Cross Heath Store Ltd | Wholesale & retail | 2023 |
| Crossburn Contracts Ltd | Construction | 2025 |
| Crossland Technology Investments Limited | Information & communication | 2013 |
| Crowd IC Limited | Extraterritorial | 2022 |
| Crown Cctv Ltd | Administrative & support | 2022 |
| Crown of Victoria Ltd | Other services | 2019 |
| Crows Nest Properties Ltd | Real estate | 2024 |
| Cruz and White Property Ltd. | Real estate | 2012 |
| Cryptowolfz Academy Ltd | Education | 2025 |
| Crystal Bright Cleaning Service Ltd | Administrative & support | 2025 |
| Crystal Choice Ltd | Other services | 2022 |
| Crystal Finish Window Cleaning Services Ltd | Administrative & support | 2025 |
| Crystal Klean Commercial Limited | Administrative & support | 2023 |
| Crystal Smile Limited | Real estate | 2012 |
| CS Drawing Services Limited | Professional & scientific | 2016 |
| Csdt Global Ltd | Real estate | 2025 |
| CSS Electrical Contracts Limited | Construction | 2015 |
| Cssc Tuition Ltd | Education | 2020 |
| Culinary LAB Limited | Hospitality | 2018 |
| Cultaholic Ventures Limited | Information & communication | 2017 |
| Culture Newcastle Ltd | Other services | 2023 |
| Culverton Enterprises Limited | Construction | 2014 |
| Cupla Bai's Ltd | Hospitality | 2024 |
| Curdworth Restaurant Limited | Hospitality | 2015 |
| Curran Environmental Re-Cycling Limited | | 2001 |
| Currapall Ltd | Construction | 2025 |