| Care Shine Cleaning Ltd | Wholesale & retail | 2025 |
| Care Solutions Group Ltd | Professional & scientific | 2021 |
| CARE21 Limited | Information & communication | 2006 |
| CARE4OCUS Homes Ltd | Health & social care | 2022 |
| Carebuild Construction & Engineering PVT. Ltd | Construction | 2023 |
| Carebuild Energy Ltd | Construction | 2024 |
| Carecabs Community Transport CIC | Transport & logistics | 2025 |
| Carecabs UK Ltd | Transport & logistics | 2025 |
| Carecrest Corporation Limited | Professional & scientific | 2020 |
| Career Choices Dewis Gyrfa Ltd. | Administrative & support | 2010 |
| Careermakers 01 Recruits Ltd | Administrative & support | 2020 |
| Careermakers 1 Recruits Ltd | Construction | 2020 |
| Careers for Life CIC | Education | 2023 |
| Careerwise Consultancy Ltd | Administrative & support | 2011 |
| Carefirst IW Ltd | Other services | 2008 |
| Carefree Cars Ltd | Wholesale & retail | 2019 |
| Carefree NW Ltd | Administrative & support | 2021 |
| Carehart Limited | Health & social care | 2013 |
| Carers HQ Ltd | Administrative & support | 2019 |
| Carexpart Auto Limited | Wholesale & retail | 2022 |
| Carey & Sons Ltd | Construction | 2021 |
| Careysfort Asset Estates Limited | Administrative & support | 2018 |
| Cargo Carriers Ltd | Transport & logistics | 2025 |
| Cargotek Limited | Construction | 2015 |
| Cargototanzania Ltd | Transport & logistics | 2017 |
| Cargow Holdings Ltd | Real estate | 2020 |
| Cariad Care Group Ltd | Health & social care | 2022 |
| Cariad Catref Ltd | Real estate | 2023 |
| Cariad Developments Ltd | Construction | 2026 |
| Cariad Energy Limited | Professional & scientific | 2019 |
| Cariad Healthcare Ltd | Health & social care | 2017 |
| Cariad Homecare Limited | Information & communication | 2019 |
| Cariad Ryan Ltd | Professional & scientific | 2020 |
| Caribbean and Organization of American States African Diaspora Affairs Ltd | Other services | 2021 |
| Caribbean Food Services Ltd | Hospitality | 2022 |
| Carico Cafe Connoisseur Limited | Administrative & support | 2024 |
| Caricool Limited | Energy | 2020 |
| Carilor Ltd | Manufacturing | 2019 |
| Carina Phillips Copywriting Limited | Professional & scientific | 2014 |
| Carine Yachts Limited | Other services | 2009 |
| Caring Boat Company Ltd | Manufacturing | 2025 |
| Caring Chloe Ltd | Administrative & support | 2023 |
| Caringby Limited | Information & communication | 2021 |
| Carinho Solutions Ltd | Wholesale & retail | 2021 |
| Carish Central European Corp. Ltd | Agriculture & fishing | 2024 |
| Carl Vanderbilt Ltd | Professional & scientific | 2019 |
| Carla Transport Limited | Transport & logistics | 2015 |
| Carlamu Limited | Administrative & support | 2010 |
| Carleoom Limited | Wholesale & retail | 2025 |
| Carlines Jewellery Limited | Manufacturing | 2002 |
| Carlisle Web Offset Limited | | 1948 |
| Carlong Ltd | Real estate | 1994 |
| Carlos Caldera Creative Limited | Arts & recreation | 2026 |
| Carlos Pizza Takeaway Ltd | Hospitality | 2015 |
| Carlson Financial Ltd | Wholesale & retail | 2024 |
| Carlson Wealth Management Limited | Financial services | 2015 |
| Carlton Mews RTM Company Limited | Households | 2018 |
| Carlton Southgate Limited | Professional & scientific | 2003 |
| Carlum Ltd | Health & social care | 2021 |
| Carlyle Property Development Company Limited | Construction | 1956 |
| Carlyle Trust Limited(The) | Financial services | 1940 |
| Carmah Limited | Households | 2020 |
| Carmak Limited | Other services | 2019 |
| Carmarthen Bess Limited | Energy | 2023 |
| Carmel Productions Limited | Information & communication | 2013 |
| Carmelo Alliance PC | | 2017 |
| Carmen GS Ltd | Wholesale & retail | 2025 |
| Carmichael's A.R.C. Limited | Wholesale & retail | 2009 |
| Carmun Ltd | Wholesale & retail | 2025 |
| Carn Y Cefn RMC Ltd | Households | 2022 |
| Carnaby World Ltd | Manufacturing | 2025 |
| Carnations Limited | Wholesale & retail | 2002 |
| Carnell FOX Limited | Wholesale & retail | 2019 |
| Carnell Medical Services Ltd | Health & social care | 2021 |
| Carnetown Studios Ltd | Extraterritorial | 2014 |
| Carnvell Clothing Ltd | Wholesale & retail | 2026 |
| Carnyx Media Ltd | Professional & scientific | 2025 |
| Carole Nash Legal Services LLP | | 2012 |
| Caroline Britton Ltd | Health & social care | 2023 |
| Caroline Havard Limited | Health & social care | 2016 |
| Caroline’S New Look Limited | Other services | 2018 |
| Caron MAI Ltd | Health & social care | 2024 |
| Carpanini Carpentry Limited | Manufacturing | 2026 |
| Carpbond Limited | Arts & recreation | 2008 |
| Carpe Diem Legal Ltd | Professional & scientific | 2022 |
| Carpe Omina Holdings Ltd | Financial services | 2025 |
| Carpe Omnia Training Ltd | Education | 2020 |
| Carpentry and Placement Limited | Manufacturing | 2024 |
| Carpet Services (Cardiff) Limited | Construction | 1963 |
| Carpet World Cardiff Ltd | Wholesale & retail | 2017 |
| Carre Balfour Ltd | Wholesale & retail | 2022 |
| Carreg Adventure Limited | Hospitality | 2013 |
| Carreg Llwyd Limited | Real estate | 2025 |
| Carrel Projects Limited | Administrative & support | 2015 |
| Carrera Consult Ltd | Information & communication | 2015 |
| Carriages of Kent Ltd | Transport & logistics | 2018 |
| Carrick & Company Limited | Professional & scientific | 2014 |
| Carrigans Law Ltd | Financial services | 2017 |
| Carrington & Vale Ltd | Wholesale & retail | 2025 |
| Carrington North Ltd | Professional & scientific | 2020 |