| Business Academy and Development Plans Ltd | Administrative & support | 2019 |
| Business Brokering Solutions Limited | Administrative & support | 2010 |
| Business Energy Advisors Ltd | Energy | 2003 |
| Business Industrial Solutions Limited | Wholesale & retail | 2008 |
| Business Products Group International LLP | | 2015 |
| Busy Bees Patchwork Limited | Arts & recreation | 2001 |
| Busy Kitchen Ltd | Hospitality | 2024 |
| Butcherlab Limited | Information & communication | 2015 |
| Butter BEE Property Ltd | Real estate | 2021 |
| Buyloft Ltd | Wholesale & retail | 2025 |
| Buyright Homes Limited | Administrative & support | 2006 |
| BVD Marine Limited | Wholesale & retail | 2011 |
| BVS (IOW) Limited | Wholesale & retail | 2010 |
| BW Cars Private Hire Ltd | Transport & logistics | 2022 |
| BW Mobile Tyres Limited | Wholesale & retail | 2025 |
| Bwcf Ltd | Manufacturing | 2018 |
| BWS Home Improvements Limited | Construction | 2020 |
| BXL 438 Limited | Hospitality | 2022 |
| Byngs Properties Isle of Wight Ltd | Real estate | 2023 |
| C & E Travel Limited | Transport & logistics | 2012 |
| C & H Dental Laboratory Ltd | Manufacturing | 2025 |
| C & J Scaffolding Ltd | Construction | 2020 |
| C & K Sparkles Cleaning Limited | Administrative & support | 2006 |
| C & L Driveways Limited | Construction | 2007 |
| C & M Birchard Transport Limited | Transport & logistics | 2016 |
| C & P Transport Limited | Transport & logistics | 2019 |
| C & T Richardson Ltd | Construction | 2017 |
| C and C Caterers Limited | Hospitality | 2017 |
| C Andrew Contracting Limited | Administrative & support | 2014 |
| C C N Contractor Ltd | Manufacturing | 2022 |
| C D S (UK) Limited | Manufacturing | 2011 |
| C J Donovan Limited | Professional & scientific | 2012 |
| C J GAS Engineering Ltd. | Manufacturing | 2013 |
| C L Digital Holdings Ltd | Financial services | 2023 |
| C L Talent House Ltd | Other services | 2026 |
| C Peters Property Ltd | Real estate | 2024 |
| C Q Cleaning Services Limited | Administrative & support | 2019 |
| C R Rees & Sons Limited | Agriculture & fishing | 2014 |
| C Rengert & Company Limited | Professional & scientific | 2006 |
| C S Waste Limited | Water & waste | 2002 |
| C T J Homes Ltd | Construction | 2025 |
| C Wood Heating & Plumbing Services Ltd | Construction | 2025 |
| C&A Food Group Ltd | Wholesale & retail | 2022 |
| C&A Food Group Newport Limited | Wholesale & retail | 2026 |
| C&A Rental Properties Ltd | Real estate | 2025 |
| C&F Care Limited | Health & social care | 2018 |
| C&J Caterer’S T/A Oddfellows Arms Ltd | Hospitality | 2020 |
| C&J Housing Ltd | Real estate | 2025 |
| C&K Payne Property Ltd | Real estate | 2025 |
| C&M701 Limited | Hospitality | 2021 |
| C&P Vehicles Limited | Administrative & support | 2023 |
| C&R Bars Ltd | Hospitality | 2026 |
| C-Bloc Productions Limited | Information & communication | 2022 |
| C-Kim Ltd. | Construction | 2005 |
| C. C. Legal Consult Limited | Professional & scientific | 2024 |
| C. G. Urry Building Services Ltd | Construction | 2024 |
| C. Still Limited | Arts & recreation | 2003 |
| C.D.L Carpentry Ltd | Manufacturing | 2025 |
| C.H. Bailey Group Limited | Professional & scientific | 1923 |
| C.Hillman Ltd | Other services | 2026 |
| C.J.N. Engineering Limited | Manufacturing | 2001 |
| C.K. Blades Ltd | Other services | 2023 |
| C.L.I.C. Ltd | Construction | 2012 |
| C.M. Consultants (Magor) Limited | Information & communication | 2011 |
| C.Mac Optics Limited | Wholesale & retail | 2007 |
| C.P.S Glass & Glazing Limited | Construction | 2021 |
| C.Williams Traffic Management Limited | Construction | 2025 |
| CA45 Sports Ltd | Arts & recreation | 2025 |
| CAB Accountancy and Business Solutions Ltd | Professional & scientific | 2022 |
| CAB X Ltd | Transport & logistics | 2022 |
| CAD Fabrications Limited | Manufacturing | 2002 |
| Cadell Capital Limited | Financial services | 2019 |
| Cadell Holdings Limited | Financial services | 2019 |
| Cadell Investments Limited | Financial services | 2019 |
| Cadlan Property Ltd | Real estate | 2025 |
| Cadwell Consulting Limited | Professional & scientific | 2023 |
| CAE Gorlan Court Limited | Households | 1997 |
| Caer Holdings (Wales) Ltd | Professional & scientific | 2025 |
| Caerau Crescent Management Limited | Real estate | 1999 |
| Caerau ELY Football Club Ltd | Arts & recreation | 2026 |
| Caerhyn Venue Limited | Hospitality | 2019 |
| Caerleon A.F.C Youth CIC | Arts & recreation | 2024 |
| Caerleon Carpets Ltd | Wholesale & retail | 2021 |
| Caerleon Cleaning Team Ltd | Administrative & support | 2025 |
| Caerleon Hotels Limited | Hospitality | 1995 |
| Caerleon Red Lion Ltd | Hospitality | 2020 |
| Caerleon Restaurant Limited | Hospitality | 2023 |
| Caerleon Stores Limited | Wholesale & retail | 2019 |
| Caernarvon Lodge (Shanklin) Management Company Limited | Households | 1995 |
| Caerwent Day Nursery (Childcare Services) Ltd | Health & social care | 2024 |
| Cafe Central (Cardiff) Limited | Hospitality | 2014 |
| Cafe Utopia Ltd | Hospitality | 2025 |
| Caffe Isola Limited | Hospitality | 2026 |
| Caitscollection CYF | Wholesale & retail | 2025 |
| Cakelabnpt Ltd | Wholesale & retail | 2023 |
| Calamont Group Limited | Professional & scientific | 2025 |
| Calbourne Classics Limited | Wholesale & retail | 2024 |
| Calbourne Water Mill Cafe Limited | Hospitality | 2014 |
| Calbourne Water Mill Heritage CIC | Arts & recreation | 2026 |
| Calcoop Construction & Property Maintenance Limited | Construction | 2020 |