| Care Crew (Somerset) Limited | Administrative & support | 2022 |
| Care Crew (Swindon) Limited | Administrative & support | 2021 |
| Care Crew (Wigan) Limited | Administrative & support | 2021 |
| Care Crew (Wolverhampton) Limited | Administrative & support | 2023 |
| Care for Wiltshire Ltd | Administrative & support | 2025 |
| CARE247SOLUTIONS Recruitment Limited | Health & social care | 2022 |
| Career Direct UK Limited | Administrative & support | 2010 |
| Careerships Limited | Professional & scientific | 2020 |
| Caremax Healthcare Ltd | Health & social care | 2023 |
| Carenest Support Services Ltd | Health & social care | 2026 |
| Carenza Developments Ltd. | Construction | 2006 |
| Caresims Ltd | Information & communication | 2025 |
| Carestream Home Care LLP | | 2019 |
| Carestream Home Care Services Limited | Health & social care | 2021 |
| Carey I.T. Services Ltd | Wholesale & retail | 2018 |
| Carfax Health Enterprise Community Interest Company | Real estate | 2009 |
| Carfix Swindon Ltd | Wholesale & retail | 2025 |
| Carib Mobile Catering Ltd | Hospitality | 2019 |
| Caring@Home Ltd | Public administration | 2020 |
| Carite Holdings Ltd | Wholesale & retail | 2020 |
| Carite Ltd | Wholesale & retail | 2009 |
| Carite Sales Ltd | Wholesale & retail | 2023 |
| Carite Service Centre Limited | Wholesale & retail | 2018 |
| Carkey Locksmith Ltd | Wholesale & retail | 2013 |
| Carle's Coffee Limited | Hospitality | 2021 |
| Carlivant Ltd | Professional & scientific | 2019 |
| Carlos Azevedo Ltd | Professional & scientific | 2026 |
| Carlton Dwayne Michael Mclawrence Limited | Extraterritorial | 2024 |
| Carlton Gate (Broome Manor) Residents Limited | Households | 1975 |
| Carlton Services UK Limited | Construction | 2000 |
| Carly Smith Veterinary Services Ltd | Professional & scientific | 2026 |
| Carnedd WEN Wind Farm Limited | Professional & scientific | 2006 |
| Carolette Cleaning LLP | | 2023 |
| Caron Roberts Equestrian Limited | Arts & recreation | 1998 |
| Carongill Limited | Real estate | 1992 |
| Carooana Ltd | Transport & logistics | 2020 |
| Carpathia Analysis Limited | Information & communication | 2019 |
| Carpe Diem Design & Consultancy Ltd | Professional & scientific | 2020 |
| Carpet Magic Ltd | Wholesale & retail | 2018 |
| Carpet Warehouse Swindon Ltd | Wholesale & retail | 2013 |
| Carr's Smart Choice Ltd | Wholesale & retail | 2023 |
| Carrington Gardens Limited | Households | 2006 |
| Carrios Technology Ltd | Information & communication | 2026 |
| Carr’S Fleet Services Ltd | Wholesale & retail | 2025 |
| Carsync.Uk Ltd | Wholesale & retail | 2025 |
| Carter Projects Limited | Real estate | 2013 |
| Carter Read & Dove Solicitors LLP | | 2019 |
| Carter Scenery Factory Ltd | Professional & scientific | 2023 |
| Carters Field Limited | Construction | 2020 |
| Carthaginian Investment Ltd | Hospitality | 2024 |
| Cartoconsult Limited | Professional & scientific | 2015 |
| Cartostrip Ltd | Administrative & support | 2009 |
| Cartus Business Answers (NO.2) PLC | Extraterritorial | 1989 |
| Cartus Holdings Limited | Construction | 1999 |
| Cartus Limited | Construction | 1979 |
| Cartus Services II Limited | Professional & scientific | 1987 |
| Cartus UK PLC | Construction | 1989 |
| Cartzy Ltd | Wholesale & retail | 2025 |
| Caru Spirits Ltd | Wholesale & retail | 2022 |
| Carwash Daci Limited | Administrative & support | 2026 |
| Casa DEL Tapas Ltd | Hospitality | 2025 |
| Casa Mexicanna Ltd | Hospitality | 2018 |
| Casafern Wholesale Limited | Wholesale & retail | 2025 |
| Casarocha Ltd | Real estate | 2025 |
| CASCADE3D Limited | Information & communication | 2016 |
| Cashplus Property Investment Ltd | Real estate | 2025 |
| Cassie Creations Photography Limited | Professional & scientific | 2016 |
| Casslows UK Ltd | Hospitality | 2025 |
| Cassone Ltd | Hospitality | 2021 |
| Castle Eaton Vehicle Services Limited | Wholesale & retail | 2014 |
| Castle White-Bbkh Limited | Hospitality | 2026 |
| Castlewood (Commercial) Properties Limited | Construction | 2011 |
| Castlewood Properties Ventures Ltd | Construction | 2016 |
| Cat Consulting Services Ltd | Professional & scientific | 2018 |
| Catalent CTS (Edinburgh) Limited | Manufacturing | 2004 |
| Catalent CTS (Wales) Limited | Professional & scientific | 1998 |
| Catalent CTS UK Holding Limited | Financial services | 2012 |
| Catalent Micron Technologies Limited | Manufacturing | 1980 |
| Catalent MTI Pharma Solutions Limited | Manufacturing | 2012 |
| Catalent Pharma Solutions Limited | Professional & scientific | 1999 |
| Catalent U.K. Swindon Holding II Limited | Professional & scientific | 2001 |
| Catalyst & Co Corp Ltd | Manufacturing | 2020 |
| Catdaggermills Ltd | Hospitality | 2025 |
| Catedral DO Avivamento Limited | Other services | 2023 |
| Catering Tech Services Limited | Manufacturing | 2010 |
| Catheline Ltd | Professional & scientific | 2021 |
| Cathw Ltd | Health & social care | 2018 |
| Cavalerul DE Nisip Limited | Professional & scientific | 2015 |
| Cavalry Business Consulting Ltd | Information & communication | 2020 |
| Caversham Sushi Ltd | Wholesale & retail | 2018 |
| Cavingham Ltd | Real estate | 2021 |
| Cazandy Solutions Ltd | Administrative & support | 2013 |
| Cazniatech Limited | Information & communication | 2014 |
| CB Event Management Limited | Administrative & support | 2016 |
| CB Paraplanning Ltd | Financial services | 2013 |
| CB Plant Limited | Construction | 2024 |
| Cbed Games Limited | Information & communication | 2024 |
| Cbrh Ltd | Financial services | 2023 |
| Cbusiness Consultancy Limited | Professional & scientific | 2003 |
| CBX Electrical Ltd | Construction | 2026 |