| Car and Watch Competitions Limited | Gerrards Cross | 2026 |
| Car Boot Records Limited | London | 2011 |
| Car Park Valeting (Operations) Ltd | Haymarket | 1998 |
| Car Radio Fitting Specialists Limited | Cornwall | 1979 |
| Cara Fitness and Events Ltd | Maidstone | 2025 |
| Cara Gainer Golf Ltd | Bromsgrove | 2023 |
| Cara Rose Music Limited | Glasgow | 2025 |
| Carabas Creative Limited | Sheffield | 2025 |
| Carabosse Theatre Company C.I.C. | Milton Keynes | 2013 |
| Caradog Promotions Ltd | Newport | 2017 |
| Caradon Hill Trekking and Equestrian Centre Ltd | Liskeard | 2014 |
| Caraleso Ltd | Oxford | 2026 |
| Caramaka Culture Ltd | Coventry | 2017 |
| Caramel Entertainment Ltd | London | 2018 |
| Caramel Records Limited | Fareham | 2022 |
| Carasports Limited | Worsley | 2024 |
| Caravan Productions Ltd | London | 2021 |
| Carbeth Keepsake Ltd | Clydebank | 2012 |
| Carbisdale Castle & Forest Preservation Board CIC | Ardgay | 2025 |
| Carbisdale Castle Ltd | Ardgay | 2023 |
| Carbon 6 Records Limited | Harlow | 2017 |
| Carbon Art 45 Limited | Buckingham | 2012 |
| Carbon Car Competitions Ltd | Barrow-In-Furness | 2025 |
| Carbon Coaching Ltd | Carluke | 2022 |
| Carbon Earth Art Ltd | London | 2021 |
| Carbon Fiit Limited | Newport | 2019 |
| Carbon Fitness Cornwall Ltd | Camborne | 2025 |
| Carbon Fitness Ltd | Dunfermline | 2023 |
| Carbon Sublime Ltd | Ashton-Under-Lyne | 2013 |
| Carbon Theatre and Cultural Projects Ltd. | Wigan | 2018 |
| Carbon/Silicon Records Limited | London | 2007 |
| Carbonclear Motorsports Ltd | Coventry | 2025 |
| Carbooty Music Limited | Manchester | 2014 |
| Carcanet Limited | Dorchester | 2024 |
| Card Maker Ltd. | Cleethorpes | 2012 |
| Cardboard Adventures Ltd | Bristol | 2023 |
| Cardboard and Coffee Games Ltd | Bonnyrigg | 2016 |
| Cardboard Box Theatre Company CIC | Matlock | 2026 |
| Cardboard Citizens | London | 1994 |
| Cardboard Crunch Ltd | Inverness | 2019 |
| Cardboard Productions Ltd | Bristol | 2024 |
| Carderry Limited | Worcestershire | 1993 |
| Cardiff Aqua Park Limited | Lichfield | 2016 |
| Cardiff Bay Kayaking Limited | Cardiff | 2022 |
| Cardiff Bay Personal Fitness Ltd | Cardiff | 2012 |
| Cardiff Bay Yacht Club Ltd | Ferry Road | 1995 |
| Cardiff Beach Volleyball Club Ltd | Cardiff | 2017 |
| Cardiff Card Show Ltd | Ebbw Vale | 2025 |
| Cardiff City (House of Sport) Limited | Cardiff | 2010 |
| Cardiff City Football Club (Holdings) Limited | Cardiff | 2000 |
| Cardiff City Football Club Limited | Cardiff | 1910 |
| Cardiff City Premier Seating Limited | Cardiff | 2007 |
| Cardiff City Stadium Limited | Cardiff | 2005 |
| Cardiff Community Meetup Limited | Cardiff | 2024 |
| Cardiff Cotswold Opera Ltd | Stroud | 2024 |
| Cardiff Dance Festival | Cardiff | 2013 |
| Cardiff Draconians FC Limited | Cardiff | 2026 |
| Cardiff Fire Limited | Cardiff | 2023 |
| Cardiff Fitness Limited | Cardiff | 2015 |
| Cardiff Golf Centre Ltd | Cardiff | 2004 |
| Cardiff Judo Academy CYF | Newport | 2023 |
| Cardiff Landscaping & Maintenance Services Limited | Cardiff | 2009 |
| Cardiff Martial Arts Academy Limited | Cardiff | 2011 |
| Cardiff Martial Arts Limited | Cardiff | 2005 |
| Cardiff Mela Limited | Newport | 2019 |
| Cardiff Metropolitan University Football Club Limited | Cardiff | 2024 |
| Cardiff Music School Limited | Pengam | 2014 |
| Cardiff Olympic Gymnastics | Cardiff | 2008 |
| Cardiff Personal Training Studio Limited | Cardiff | 2017 |
| Cardiff Queer Orchestra CIC | Cardiff | 2025 |
| Cardiff Railway Company Limited | Cardiff | 2017 |
| Cardiff Rugby Club Limited | Cardiff | 2019 |
| Cardiff Rugby Football Club Limited | Cardiff | 2003 |
| Cardiff Rugby Limited | Leeds | 1996 |
| Cardiff Soft Play Limited | Cardiff | 2013 |
| Cardiff Television Ltd | Cardiff | 1987 |
| Cardiff Theatrical Services Limited | Cardiff | 1983 |
| Cardiff Umbrella CIC | Cardiff | 2023 |
| Cardiff Wales Lesbian GAY Bisexual Transgender Mardi Gras | Penarth | 2010 |
| Cardiff Yachting Limited | Pontypridd | 2017 |
| Cardigan and District Agricultural & Maritime Museum | Cardigan | 2009 |
| Cardigan Bay Active Ltd | Llandysul | 2011 |
| Cardigan Bay Fishermans Association Limited | Aberystwyth | 2003 |
| Cardigan Bay Leisure Ltd | Llandysul | 2017 |
| Cardigan Bay Watersports | Aberystwyth | 2006 |
| Cardigan Castle Enterprises Limited | Cardigan | 2010 |
| Cardigan Climbing CIC | Cardigan | 2026 |
| Cardigan Island Ltd | Cardigan | 2015 |
| Cardigan Music Ltd | West Wickham | 2019 |
| Cardigle Limited | Brighton | 2008 |
| Cardinal Rose Limited | Clacton On Sea | 2022 |
| Cardinal Sailing Ltd | Nottingham | 2013 |
| Cardinbrook Limited | London | 1973 |
| Cardington Studio Services Ltd | Bedford | 2024 |
| Cardio Dancefit Limited | London | 2021 |
| Cardio IS Key Fitness Ltd | Southport | 2016 |
| Cardio Tennis Ltd | Bridgnorth | 2011 |
| Cardle Boxing Fitness Limited | Manchester | 2014 |
| Cardney Estate Limited | Perth | 2015 |
| Cardwala Ltd | Rotherham | 2025 |