| Casa Tang Limited | Real estate | 2024 |
| Casa Vignali Ltd | Extraterritorial | 2024 |
| Casablanca Estates Limited | Real estate | 2014 |
| Casam Consulting Ltd | Information & communication | 2026 |
| Casamia Group Limited | Construction | 2026 |
| Casamia Homes Ltd | Construction | 2001 |
| Casamia Investments Limited | Construction | 2026 |
| Casbros Limited | Construction | 2024 |
| Cascano Property Ventures Limited | Real estate | 2024 |
| Case Recoveries Limited | Professional & scientific | 2015 |
| Casella Properties Ltd | Real estate | 2024 |
| Casey & Jones Developments Limited | Real estate | 2020 |
| Cashmere Properties Limited | Real estate | 2022 |
| Cask Group Holdings Limited | Hospitality | 2025 |
| Caslon Press Ltd | Manufacturing | 2023 |
| Caso Developments Limited | Construction | 2019 |
| Casp Developments Limited | Real estate | 2017 |
| Cassiopeia Solar Limited | Professional & scientific | 2022 |
| Cassland Estates Limited | Real estate | 2015 |
| Castellum Law Limited | Professional & scientific | 2025 |
| Castle Bedrooms Limited | Construction | 2002 |
| Castle Blinds Midlands Limited | Manufacturing | 2023 |
| Castle Cars (Burton) Ltd | Wholesale & retail | 2025 |
| Castle Container Services Limited | Manufacturing | 1995 |
| Castle Damp and Timber Specialists Ltd | Construction | 2006 |
| Castle Donington Engineering Limited | Manufacturing | 2008 |
| Castle Donington Residents Management Company Limited | Households | 2019 |
| Castle Donington Rugby Union Football Club Limited | Arts & recreation | 2000 |
| Castle Donington Upvc Limited | Construction | 2003 |
| Castle EV Limited | Wholesale & retail | 2013 |
| Castle Events & Parties Ltd | Arts & recreation | 2025 |
| Castle Farm Properties Limited | Construction | 2019 |
| Castle Farms Nottingham Limited | Agriculture & fishing | 2025 |
| Castle Foods Donington Limited | Hospitality | 2023 |
| Castle Holdings Investment Limited | Financial services | 2022 |
| Castle Homes Property Management Limited | Real estate | 2003 |
| Castle House Nottingham Limited | Hospitality | 2021 |
| Castle Installation Services Ltd | Construction | 2023 |
| Castle Networks Limited | Construction | 2003 |
| Castle News & Distribution Ltd | Wholesale & retail | 2018 |
| Castle Peak Estates Ltd | Real estate | 2024 |
| Castle Performance Limited | Administrative & support | 2014 |
| Castle Pizza Fish Chips Bar Ltd | Hospitality | 2017 |
| Castle Play Ltd | Administrative & support | 2026 |
| Castle Portcullis Holdings Limited | Financial services | 2025 |
| Castle Sawmills Management Company Limited | Real estate | 2007 |
| Castle Telemetry Services Ltd | Administrative & support | 2017 |
| Castle UK Bidco Limited | Financial services | 2021 |
| Castle UK Midco 1 Limited | Financial services | 2022 |
| Castle UK Midco 2 Limited | Financial services | 2021 |
| Castledine Construction Limited | Construction | 2003 |
| Castledine Driving Force Limited | Financial services | 1988 |
| Castlegate (Tutbury) Limited | Real estate | 2006 |
| Castlegate 755 Limited | Financial services | 2016 |
| Castleward Residents Group C.I.C. | Health & social care | 2025 |
| Castleway Holdings Ltd | Real estate | 2021 |
| Castlewood Joinery Products Limited | Wholesale & retail | 2022 |
| Cata C&M Ltd | Transport & logistics | 2019 |
| Catch More Media Ltd | Information & communication | 2017 |
| CATCH23 Consultancy Ltd | Information & communication | 2014 |
| Catchpole Lettings Ltd | Real estate | 2022 |
| Catchpole Property Ltd | Construction | 2021 |
| Catchpole Stays Ltd | Construction | 2019 |
| Catcubcafe Limited | Manufacturing | 2026 |
| Catering Derby Ltd | Hospitality | 2024 |
| Catering Hygiene Equipment Limited | Wholesale & retail | 1994 |
| Cathedral Property Services Ltd | Real estate | 2021 |
| Cathedral Support Limited | Health & social care | 2017 |
| Catherine Gilligan Ltd | Health & social care | 2022 |
| Cathexis Psychotherapy Limited | Health & social care | 2012 |
| Cathlon Enterprises Limited | Health & social care | 2013 |
| Cats & Dogs Whiskers Ltd | Administrative & support | 2007 |
| Cattermole Group Ltd | Manufacturing | 2017 |
| Cattington Property Ltd | Real estate | 2022 |
| Catwalk Beauty Academy Limited | Other services | 2018 |
| Cavan Drive Chaddesden Store Limited | Wholesale & retail | 2025 |
| Cavehill Systems Limited | Professional & scientific | 2013 |
| Cavendish Car Wash Ltd | Administrative & support | 2025 |
| Cavendish Health Provider Ltd | Health & social care | 2010 |
| Cavendish Mill (Matlock) Management Co Limited | Real estate | 2003 |
| Cavendish Philatelic Auctions Limited | Other services | 2016 |
| Cavendish Phones Ltd | Wholesale & retail | 2021 |
| Cavin Trading Limited | Wholesale & retail | 2024 |
| Cavitas Prime Limited | Wholesale & retail | 2016 |
| Cawdell Brickwork Ltd | Construction | 2014 |
| Cawdell Building Services Ltd | Construction | 2017 |
| Cawston Cleaning Services Ltd | Administrative & support | 2025 |
| Cawthorne Trading Limited | Real estate | 2011 |
| Caxton Mechanical and Electrical Limited | Administrative & support | 2018 |
| CAZ Trading Ltd | Other services | 2018 |
| CB & LB Services Ltd | Construction | 2023 |
| CB Consulting (Derby) Limited | Information & communication | 2024 |
| CB Floors Direct Ltd | Construction | 2021 |
| CB91 Ltd | Other services | 2026 |
| CBG TEC Ltd | Construction | 2024 |
| CBM Properties Limited | Real estate | 2005 |
| CBP Property Holdings Ltd | Real estate | 2026 |
| CBR LAD Transport Ltd | Transport & logistics | 2018 |
| Cbvc Vehicle Management Limited | Administrative & support | 2008 |
| CC Inks Ltd | Wholesale & retail | 2007 |