| BJT Aerotech Limited | Manufacturing | 2017 |
| Bloomtech Business Services Limited | Financial services | 2024 |
| Bluck Surveying Ltd | Professional & scientific | 2025 |
| Blue Seas Properties Limited | Real estate | 2025 |
| BM Aerotech Limited | Manufacturing | 2020 |
| Body Ethos Ltd | Wholesale & retail | 2018 |
| Bohai Global Ltd | Wholesale & retail | 2026 |
| Bolt Alarm Response Ltd | Administrative & support | 2020 |
| Boulton Enterprise Solutions Ltd | Manufacturing | 2015 |
| Boulton Property Solutions Ltd | Real estate | 2024 |
| BPH Holdings Limited | Hospitality | 2025 |
| BR Vape Ltd | Wholesale & retail | 2025 |
| Brain Injury Wales Limited | Health & social care | 2007 |
| Bran Consulting Ltd | Manufacturing | 2016 |
| Breaking Waves Gifts Ltd | Wholesale & retail | 2022 |
| Breaksea (Holdings) Limited | Financial services | 2013 |
| Breaksea Residential Homes Limited | Health & social care | 2000 |
| Breeze Entertainments Limited | Hospitality | 2026 |
| Brett Warlow Limited | Information & communication | 2009 |
| Brick and Wood Property Services Limited | Construction | 2021 |
| Bridgend Asbestos Services Limited | Professional & scientific | 2003 |
| Bridgend Windows and Maintenance Ltd | Extraterritorial | 2026 |
| Bridgend Windows Ltd | Extraterritorial | 2026 |
| Brogden Management Company Limited | Households | 2009 |
| Bronco Sound Limited | Information & communication | 2008 |
| Brushstrokes Porthcawl Limited | Wholesale & retail | 2021 |
| BS Aero Servicing Ltd | Manufacturing | 2025 |
| Bubble Construction Limited | Construction | 2006 |
| Business Bullet Ltd. | Information & communication | 2015 |
| C & B Aviation Limited | Manufacturing | 2014 |
| C&S Aero Limited | Manufacturing | 2015 |
| C. Patrick Evans Entertainments Limited | Arts & recreation | 1966 |
| Camaero Limited | Transport & logistics | 2004 |
| Cambrian Holidays & Travel Limited | Extraterritorial | 1991 |
| Camerell Limited | Construction | 2023 |
| Campsite Wifi Limited | Information & communication | 2022 |
| Canvasbayuk Limited | Wholesale & retail | 2012 |
| Capital EAR WAX Removal Limited | Health & social care | 2024 |
| Caravania Limited | Professional & scientific | 2009 |
| Cardiff Asbestos Services Limited | Professional & scientific | 2017 |
| Cardiff Limited | Extraterritorial | 2021 |
| Carlton House Porthcawl Limited | Households | 2012 |
| Carpet Care South Wales Ltd | Wholesale & retail | 2025 |
| Cartref Residential Homes Limited | Health & social care | 2013 |
| Castle Drives (South Wales) Limited | Construction | 2014 |
| Castle Landscapes (Porthcawl) Ltd | Administrative & support | 2021 |
| CB Turbines Limited | Transport & logistics | 2004 |
| Ceffyl DWR Ltd | Professional & scientific | 2026 |
| Celtic Cruises Limited | Transport & logistics | 2001 |
| Celtic Driveways & Bricklaying Co Ltd | Construction | 2025 |
| CF Roger Limited | Hospitality | 2022 |
| Charriot Aviation Ltd | Manufacturing | 2019 |
| CHECK4ASBESTOS Ltd | Professional & scientific | 2025 |
| Cheeky Chillies Limited | Hospitality | 2019 |
| Chester Hardcastle Associates Limited | Professional & scientific | 2010 |
| Chinton Engineering Limited | Manufacturing | 2025 |
| Chrisdebell Engineering and Leisure Limited | Manufacturing | 1995 |
| CHS Porthcawl Ltd | Education | 2026 |
| CJ Financial Services Limited | Financial services | 2006 |
| Clare House Independent School Trust Limited | Education | 2025 |
| Cleaning With Distinction Ltd | Administrative & support | 2021 |
| Climatech Services Limited | Construction | 2017 |
| Clos - YR - Ysgol Parks Management Company Ltd | Households | 2022 |
| CMG Maintenance Limited | Administrative & support | 2024 |
| CMK Aero Limited | Manufacturing | 2018 |
| Cold Busters Porthcawl Ltd | Construction | 2025 |
| Combicare Bridgend Limited | Construction | 2018 |
| Composite Mech Ltd | Manufacturing | 2025 |
| Connelly Aviation Limited | Transport & logistics | 2009 |
| Contemporancient Theatre Community Interest Company | Education | 2020 |
| Coolcon Limited | Wholesale & retail | 2007 |
| Coolkids Computing Ltd | Education | 2014 |
| Coopers 55 Ltd | Hospitality | 2017 |
| Coretsetc Limited | Professional & scientific | 2007 |
| Corner Coffee Union Ltd | Hospitality | 2019 |
| Cosmetic Injectables Porthcawl Limited | Other services | 2021 |
| Costello Williams Limited | Other services | 2025 |
| Cosy Corner Lounge Ltd | Hospitality | 2016 |
| Cotostrike Limited | Professional & scientific | 2022 |
| Cpcc Ltd | Professional & scientific | 2025 |
| Craig Milligan EH Ltd | Professional & scientific | 2021 |
| Croesy Limited | Wholesale & retail | 2021 |
| Crole Properties Limited | Real estate | 2014 |
| Cvs-Technical Ltd | Information & communication | 2021 |
| Cydena Ltd | Information & communication | 2025 |
| Cydentity Academy Ltd | Education | 2025 |
| Cydentity Limited | Information & communication | 2024 |
| D Joyce Construction Limited | Construction | 2020 |
| D. M. Bricklaying Limited | Construction | 2001 |
| D.G.Weemes Ltd | Manufacturing | 2017 |
| Dalpen Limited | Real estate | 1977 |
| DAN Aviation Consulting Limited | Manufacturing | 2016 |
| Dang J Ltd | Wholesale & retail | 2024 |
| Dash Country and Pets Ltd | Wholesale & retail | 2025 |
| DAT Aerotech Limited | Transport & logistics | 2010 |
| David Morgan Plumbing & GAS Heating Engineers Limited | Construction | 2010 |
| DB Aviation Limited | Manufacturing | 2023 |
| DC Aerotech Limited | Manufacturing | 2016 |
| DCN Renewables Limited | Construction | 2022 |
| DCS Financial Ltd | Financial services | 2013 |