| Cleckheaton Motor Sales (Yorkshire) Limited | Wholesale & retail | 2020 |
| Cleckheaton Road Management Company Ltd | Households | 2015 |
| Cleen-Bees Ltd | Administrative & support | 2019 |
| Cleftwave Audio Ltd | Information & communication | 2026 |
| Clegg Properties (Yorkshire) Ltd | Real estate | 2025 |
| Cleggacy Financial Limited | Financial services | 2023 |
| Clemie Properties Ltd | Real estate | 2026 |
| Clems Nation Ltd | Wholesale & retail | 2025 |
| Clenshaws Ltd | Real estate | 2016 |
| Cleopatra Jewellery Ltd | Wholesale & retail | 2023 |
| Clerking for Governors Limited | Education | 2009 |
| Cleveland FM Services (Holdings) Limited | Administrative & support | 2004 |
| Cleveland FM Services Limited | Administrative & support | 2004 |
| Cleveland Retail Systems Ltd | Manufacturing | 2002 |
| Cleventics Ltd | Information & communication | 2024 |
| Clever PIG Limited | Information & communication | 2017 |
| Cleverlogic IT Limited | Information & communication | 2025 |
| Clevra Ltd | Wholesale & retail | 2025 |
| CLG Mechanical & Electrical Contractors Limited | Construction | 2008 |
| Click Boost Marketing Ltd | Professional & scientific | 2024 |
| Click REV Marketing Limited | Professional & scientific | 2019 |
| Click Therapy Recordings Ltd | Manufacturing | 2010 |
| Clickfile Limited | Information & communication | 2008 |
| Clickpay Contractor Services Limited | Administrative & support | 2024 |
| Client Cover Limited | Financial services | 2008 |
| Client Marketing Limited | Professional & scientific | 2013 |
| Client Portfolio Management Ltd | Professional & scientific | 2025 |
| Clients With Flux Ltd | Professional & scientific | 2025 |
| Cliff Cottage BD20 Ltd | Hospitality | 2022 |
| Cliff Enterprise Ltd | Other services | 2024 |
| Cliff Solutions Limited | Information & communication | 2008 |
| Cliffe Consultants Ltd | Administrative & support | 2018 |
| Clifford Bartle Haulage Ltd | Transport & logistics | 2002 |
| Clifford James Financial Services Limited | Financial services | 2019 |
| Clifford Moor Road Nursery Limited | Real estate | 2021 |
| Clifford Property Management Limited | Real estate | 2021 |
| Clift Properties Limited | Real estate | 2020 |
| Clikmedia Limited | Construction | 2020 |
| Clima One Ltd | Construction | 2026 |
| Climate Innovation District 216 CIC | Real estate | 2022 |
| Climate Innovation District 247 CIC | Real estate | 2022 |
| Climate Innovation District 312 CIC | Real estate | 2018 |
| Climate Innovation District Phase 1B Ltd | Real estate | 2019 |
| Climate Innovation District Phase 2 Ltd | Real estate | 2015 |
| Climate Innovation District Phase 3 Ltd | Real estate | 2017 |
| Climate Innovation District Phase 4 Ltd | Real estate | 2021 |
| Climate Wise Installation Ltd | Construction | 2025 |
| Climateco Limited | Construction | 2026 |
| Climatix Group Limited | Construction | 2008 |
| Climb Hard BE Kind Mountaineering Limited | Arts & recreation | 2025 |
| Climb Ventures Limited | Professional & scientific | 2025 |
| Clime Energy Ltd | Construction | 2015 |
| Clinat Healthcare Service Limited | Public administration | 2024 |
| Clinic 360 MSK Limited | Health & social care | 2021 |
| Clinical Photography UK Limited | Professional & scientific | 2017 |
| Clinical Psychology Consultancy Limited | Health & social care | 2021 |
| Clinical Technology Limited | Health & social care | 2014 |
| Clinix Systems Ltd | Information & communication | 2024 |
| Clinton AI Ltd | Information & communication | 2026 |
| Clinton Creative Ltd | Information & communication | 2024 |
| Clip N Climb Leeds Limited | Arts & recreation | 2019 |
| Clipper BCS LLP | | 2014 |
| Clipper Investments Group Limited | Financial services | 2025 |
| Cliq IT Ltd | Information & communication | 2022 |
| Clique (H) Ltd | Arts & recreation | 2018 |
| Clique Event Management Limited | Professional & scientific | 2022 |
| Clique Luxury Events Ltd | Professional & scientific | 2017 |
| Clirad Ltd | Health & social care | 2019 |
| Clitel Cleaning Services Limited | Administrative & support | 2025 |
| Clive Goldstein Ltd | Professional & scientific | 2020 |
| Cllearview Ltd | Information & communication | 2008 |
| CLO Coffee Limited | Manufacturing | 2018 |
| Cloanex Limited | Construction | 2023 |
| Clock Cards Online Limited | Administrative & support | 2008 |
| Clock Tower Rentals Limited | Real estate | 2025 |
| Clockwork Creative Technology Limited | Information & communication | 1998 |
| Clockwork Removals Limited | Transport & logistics | 2001 |
| Clodhopper Limited | Financial services | 2019 |
| Close FF Limited | Wholesale & retail | 2012 |
| Close the Gaps Ltd | Education | 2024 |
| Closegate (Durham NO. 2) Limited | Professional & scientific | 2003 |
| Closegate Hotel Development (Durham) Limited | Hospitality | 1925 |
| Closegate Hotel Developments Limited | Construction | 1998 |
| Closer Health Ltd | Information & communication | 2023 |
| Clot Media Ltd | Professional & scientific | 2019 |
| Cloth Hall Developments Limited | Real estate | 2003 |
| Cloth Hall Holdings Limited | Financial services | 2020 |
| Clothes Clinic Ltd | Wholesale & retail | 2026 |
| Clotprotect Therapeutics Limited | Professional & scientific | 2024 |
| Cloud CFO Limited | Professional & scientific | 2017 |
| Cloud Creative Management Ltd | Professional & scientific | 2026 |
| Cloud Gate Properties Limited | Other services | 2013 |
| Cloud Locum Ltd | Health & social care | 2014 |
| Cloud Monitoring Systems Ltd | Information & communication | 2013 |
| Cloud Nexus Ltd | Information & communication | 2012 |
| Cloud Nine Getaways Ltd | Real estate | 2026 |
| Cloud Nine Photography Limited | Professional & scientific | 1997 |
| Cloudapex Consulting Limited | Information & communication | 2025 |
| Cloudaura Ltd | Information & communication | 2015 |
| Cloudbar Ltd | Other services | 2026 |