| Care Regency UK Ltd | Health & social care | 2025 |
| Care to Educate Limited | Education | 2006 |
| CARE1 Professional Services Ltd | Health & social care | 2013 |
| Carechannel Ltd | Health & social care | 2017 |
| Carefully Coded Ltd | Information & communication | 2022 |
| Carepath Healthcare and Staffing Solutions Ltd | Administrative & support | 2025 |
| Caretaker@Health Ltd | Administrative & support | 2019 |
| Carey's Appliance Repairs Ltd | Other services | 2022 |
| Cargo Inspection Services Limited | Professional & scientific | 2001 |
| Cargo Secure Holdings Limited | Financial services | 2002 |
| Cargo Secure Limited | Transport & logistics | 1989 |
| Cargo Secure Transport Ltd | Transport & logistics | 2019 |
| Cargo Transportation Limited | Transport & logistics | 2025 |
| Cargo World Europe Limited | Administrative & support | 2011 |
| Cargoland Ltd | Wholesale & retail | 2020 |
| Caribbarandgrill Ltd | Hospitality | 2022 |
| Caring Souls Ltd | Health & social care | 2017 |
| Caring Wings Ltd | Health & social care | 2020 |
| Carjoma JV Ltd | Construction | 2025 |
| Carl Boardley Motorsport Limited | Arts & recreation | 2012 |
| Carlton James Private and Commercial Ltd | Financial services | 2014 |
| Carman 4SEASONS Ltd | Agriculture & fishing | 2009 |
| Carne Trade Shipping Limited | Transport & logistics | 2021 |
| Caroline Victori Ltd | Wholesale & retail | 2024 |
| Carolux Beauty Ltd | Other services | 2025 |
| Carousel Promotional Clothing UK Limited | Manufacturing | 2012 |
| Carp Gear Giveaways Limited | Wholesale & retail | 2020 |
| Carp Holdings Ltd | Wholesale & retail | 2018 |
| Carpark Surfacing Grids Ltd | Construction | 2013 |
| Carpass AI Ltd | Information & communication | 2022 |
| Carpentry and Woodwork Ltd | Manufacturing | 2023 |
| Carpentry Joinery Wright Ltd | Manufacturing | 2026 |
| Carpet Cuts Limited | Wholesale & retail | 1966 |
| Carpet Pro Fitting Ltd | Construction | 2026 |
| Carr Property Ltd | Real estate | 2025 |
| Carr Road Distribution Limited | Administrative & support | 1991 |
| Carrot Tech Ltd | Information & communication | 2020 |
| CARS2U Ltd | Wholesale & retail | 2012 |
| Carsons Life Coaching Ltd | Other services | 2020 |
| Carteme Ltd | Wholesale & retail | 2008 |
| Carter-Newlove Interiors Ltd | Manufacturing | 2019 |
| Carzet Ltd | Wholesale & retail | 2020 |
| CAS Electronics Limited | Manufacturing | 2002 |
| CAS Insurance Services Ltd | Financial services | 1997 |
| Cascadepoolstore Limited | Wholesale & retail | 2008 |
| Case Wealth Management Limited | Financial services | 2012 |
| Casera Condiments Ltd | Hospitality | 2025 |
| Cash Commercial Ltd | Transport & logistics | 2020 |
| Casilo Consultancy Ltd | Construction | 2021 |
| Casino City Limited | Extraterritorial | 2008 |
| Castle & Co.Search Ltd | Administrative & support | 2026 |
| Castle Consulting Ltd | Administrative & support | 1996 |
| Castle Electrical (Ipswich) Limited | Manufacturing | 2013 |
| Castle Marketing UK Ltd | Wholesale & retail | 2011 |
| Castleacre Insurance Services Ltd | Financial services | 2004 |
| Castlebroom Engineering Limited | Manufacturing | 1985 |
| Castons Consulting Limited | Professional & scientific | 2022 |
| Catab & Co Ltd | Construction | 2013 |
| Catallynmd Ltd | Administrative & support | 2021 |
| Catalyst Surveying Limited | Professional & scientific | 2006 |
| Catalytic Change Consulting Ltd | Professional & scientific | 2013 |
| Catautility Ltd | Construction | 2023 |
| Catch the Moon Productions Limited | Information & communication | 2005 |
| Catch Two/Five Holdings Limited | Wholesale & retail | 2023 |
| Catcheys Fruit and VEG Ltd | Wholesale & retail | 2013 |
| Cater Care Group Services Limited | Manufacturing | 2017 |
| Catercall Services Limited | Manufacturing | 2000 |
| Caterhire Suffolk Ltd | Hospitality | 2018 |
| Catering by Helen Bryce Limited | Hospitality | 2003 |
| Caterpaper Ltd | Wholesale & retail | 2024 |
| Catford Hill Ltd | Construction | 2020 |
| Catherine Aldous Design Limited | Construction | 2003 |
| Catiusablack Limited | Construction | 2024 |
| Catling Properties Limited | Real estate | 2020 |
| Cato Group Holdings Ltd | Real estate | 2020 |
| Cator Crescent UK Ltd | Real estate | 2019 |
| Catt Projects Ltd | Construction | 2022 |
| Catterick Consulting Ltd | Professional & scientific | 2026 |
| Catts Nightclub Limited | Real estate | 1998 |
| Caty Trans Ltd | Transport & logistics | 2020 |
| Cauldwell Hall RD (Management Company) Limited | Households | 2024 |
| Cauldwell Management Ltd | Real estate | 2017 |
| Causeway Cluck’D Ltd | Hospitality | 2023 |
| Cavalier Way (Bury ST Edmunds) Block Management Company Limited | Households | 2025 |
| Cavendish Global (Holdings) Ltd | Financial services | 2014 |
| Cavendish UK Holdings Ltd | Financial services | 2020 |
| CB Agencies Limited | Wholesale & retail | 2014 |
| CB Skip Services Limited | Manufacturing | 2017 |
| CB1 Venture Consulting Limited | Professional & scientific | 2019 |
| Cbds Design LLP | | 2014 |
| CBL Asset Management Limited | Professional & scientific | 2010 |
| CBS Property Limited | Real estate | 2016 |
| CBZ Chemical Investments Limited | Administrative & support | 2012 |
| CBZ Chemicals Limited | Administrative & support | 2000 |
| Cc&S Trans Ltd | Transport & logistics | 2023 |
| Ccas Limited | Professional & scientific | 1995 |
| Cckc Consulting Limited | Arts & recreation | 2016 |
| Cckc Investments Limited | Real estate | 2016 |
| CCL Cleaning Services Limited | Administrative & support | 2015 |
| CCL Property Svcs Ltd | Real estate | 2023 |