| Carters PM Limited | Real estate | 2017 |
| Carters Restaurant Limited | Hospitality | 2022 |
| Carters Surveyors Lettings Limited | Real estate | 2024 |
| Carters Surveyors Limited | Professional & scientific | 2014 |
| Carterville Limited | Professional & scientific | 2016 |
| Cartezo Ltd | Wholesale & retail | 2026 |
| Cartilage-Surgery Limited | Health & social care | 2004 |
| Cartio Express Ltd | Wholesale & retail | 2026 |
| Cartland Club Limited | Professional & scientific | 2020 |
| Cartlix Limited | Wholesale & retail | 2026 |
| Cartmell Holdings Limited | Financial services | 2002 |
| Cartnix Ltd | Wholesale & retail | 2026 |
| Carto Limited | Information & communication | 2002 |
| Cartron UK Ltd | Wholesale & retail | 2022 |
| Cartwright and COY Talent Management Ltd | Administrative & support | 2026 |
| Cartwright Arch Frames Limited | Manufacturing | 2012 |
| Cartwright Bros. (Haulage) Limited | Transport & logistics | 1962 |
| Cartwright Global Consultancy Limited | Professional & scientific | 2014 |
| Cartwright Plastering Contractors Ltd. | Construction | 2017 |
| Cartze Ltd | Wholesale & retail | 2025 |
| Carved With Care Ltd | Wholesale & retail | 2025 |
| Carviews Ltd | Wholesale & retail | 2022 |
| Carvill & Johnson Solicitors Limited | Professional & scientific | 2016 |
| Carvin Baker Ltd | Other services | 2018 |
| Carvision Creators Ltd | Manufacturing | 2023 |
| Carwadi Ltd | Hospitality | 2025 |
| Carwash Shoreham Limited | Wholesale & retail | 2017 |
| Carxsre Limited | Wholesale & retail | 2016 |
| Carys & Knightley Ltd | Arts & recreation | 2025 |
| Carys's Community Kitchen CIC | Education | 2025 |
| Carz Shop Ltd | Wholesale & retail | 2021 |
| CAS 2012 Limited | Manufacturing | 1998 |
| CAS Solutions UK Limited | Professional & scientific | 2006 |
| CAS7 Properties Ltd | Real estate | 2017 |
| Casa Amore Ltd | Manufacturing | 2026 |
| Casa Boutique Ltd | Wholesale & retail | 2025 |
| Casa Boyz Entertainment Limited | Information & communication | 2025 |
| Casa Colombo Limited | Arts & recreation | 2021 |
| Casa Comfort Properties Ltd | Hospitality | 2026 |
| Casa Crown Ltd | Wholesale & retail | 2025 |
| Casa DE Tech Limited | Information & communication | 2018 |
| Casa DEL MAR Limited | Hospitality | 2013 |
| Casa DI Stone Ltd | Wholesale & retail | 2024 |
| Casa Forte Properties Limited | Real estate | 2024 |
| Casa Glamour Ltd | Wholesale & retail | 2024 |
| Casa Harvest Limited | Real estate | 2022 |
| Casa KAI Limited | Wholesale & retail | 2023 |
| Casa Leila Limited | Real estate | 2024 |
| Casa Luxo Ltd | Hospitality | 2026 |
| Casa MIA Birmingham Limited | Real estate | 2023 |
| Casa More Interiors Limited | Professional & scientific | 2024 |
| Casa Nova Interiors Ltd | Wholesale & retail | 2026 |
| Casa Parmo Ltd | Hospitality | 2020 |
| Casa Rancha Investments Ltd | Real estate | 2023 |
| Casa Retail Group Ltd | Wholesale & retail | 2022 |
| Casa Sereno Ltd | Real estate | 2025 |
| Casa Services 24 Ltd | Administrative & support | 2009 |
| Casa Transformation Ltd | Real estate | 2026 |
| Casa Worcester Limited | Real estate | 2025 |
| Casaa Properties Ltd | Hospitality | 2024 |
| Casablanca ESC Holdings Ltd | Hospitality | 2022 |
| Casamadera Ltd | Wholesale & retail | 2025 |
| Casamera Trading Limited | Construction | 2017 |
| Casaroët Ltd | Wholesale & retail | 2022 |
| Casaura Services Ltd | Administrative & support | 2025 |
| Casavita Stays Ltd | Real estate | 2025 |
| Casbrook Fields (Michelmersh) Management Company Limited | Households | 2009 |
| Cascade Sciarts C.I.C. | Professional & scientific | 2020 |
| Casco Pizza Ltd | Hospitality | 2025 |
| Cascoe Limited | Professional & scientific | 2014 |
| Case (Midlands) Ltd | Construction | 2017 |
| Caseweighh Limited | Manufacturing | 2025 |
| Casewiz Limited | Information & communication | 2026 |
| Casey Financial Planning Limited | Financial services | 2012 |
| Casey Quality Ltd | Wholesale & retail | 2025 |
| Cash & Cart Limited | Wholesale & retail | 2024 |
| Cash 4 Gadgets Ltd | Wholesale & retail | 2025 |
| Cash Flow 4 Smes Limited | Financial services | 2009 |
| Cash Flow College Ltd | Education | 2020 |
| Cash Flow Holdings Ltd | Financial services | 2021 |
| Cash Flow With Property Ltd | Hospitality | 2020 |
| Cash Home Limited | Real estate | 2020 |
| Cash Your Property Ltd | Real estate | 2020 |
| CASH4MOBILES Ltd | Wholesale & retail | 2014 |
| Casino Skateboards Ltd | Manufacturing | 2023 |
| Cask and Corks Limited | Wholesale & retail | 2012 |
| Cask and Curry Ltd | Hospitality | 2017 |
| Casket Group Pension Trustee Limited | Professional & scientific | 1993 |
| Casket Leisure Products Limited | Professional & scientific | 1969 |
| Casket Limited | Professional & scientific | 1964 |
| Casl Stour RD Primrose (London) Property Owner Limited | Real estate | 2019 |
| Cason Crane Productions Limited | Arts & recreation | 2026 |
| Casper Advisory UK Ltd | Professional & scientific | 2024 |
| Casper Housing Ltd | Real estate | 2026 |
| Casper K9 Ltd | Administrative & support | 2024 |
| Caspian (ST Johns) Ltd | Hospitality | 2018 |
| Caspian Foods Cash & Carry Limited | Wholesale & retail | 2013 |
| Caspian Local Ltd | Hospitality | 2026 |
| Caspian Pizza & Kebab Dudley Ltd | Hospitality | 2022 |
| Caspian Pizza (UK ) Limited | Wholesale & retail | 2016 |