| Berkat Ltd | Information & communication | 2024 |
| Berridge Consultancy Ltd | Professional & scientific | 2014 |
| Bespoke Vehicle Storage Ltd | Transport & logistics | 2022 |
| Bets Auto's Ltd | Wholesale & retail | 2015 |
| Biplas Medical Limited | Manufacturing | 2008 |
| Bizza Limited | Manufacturing | 2014 |
| Blazin Vapourz LLP | | 2017 |
| Bliss - Beauty, Nails & Aesthetics Ltd | Other services | 2018 |
| Blossom Hair Design Ltd. | Other services | 2019 |
| Blythe Financial Management Limited | Professional & scientific | 2023 |
| Blythe Property Management Services Limited | Real estate | 2016 |
| BM Solutions Ltd | Construction | 2026 |
| Bodrum(Npt) Ltd | Hospitality | 2026 |
| Boilercraft Ltd | Construction | 2025 |
| Bolivar Fertility Clinic Ltd | Other services | 2018 |
| Bombini Ltd | Professional & scientific | 2025 |
| Born Untold Ltd | Manufacturing | 2017 |
| Bottle & Board Ponytclun Ltd | Hospitality | 2025 |
| Bottlers & Distillers (Wales) Limited | Manufacturing | 2018 |
| Bowman Consulting Ltd | Administrative & support | 2024 |
| Brainbox Creations Ltd | Manufacturing | 2023 |
| Brandane Group Limited | Construction | 2026 |
| Bridal Alterations Wales Ltd | Other services | 2016 |
| Bridgend Storage Solutions Limited | Administrative & support | 2020 |
| Bridgestone Autos Ltd | Wholesale & retail | 2021 |
| Broke BOY Ltd | Wholesale & retail | 2023 |
| Brookes Food Company Ltd | Hospitality | 2009 |
| Brookfield Finance Ltd | Professional & scientific | 2024 |
| Brooks Carpentry & Construction Ltd | Construction | 2020 |
| Browne & Brown IFA Ltd | Financial services | 2021 |
| Browne & Browne IFA Limited | Financial services | 2008 |
| Brycor Properties 1 Limited | Households | 2023 |
| Brycor Properties Limited | Real estate | 2025 |
| Bullring Retails Ltd | Wholesale & retail | 2025 |
| Burbspace Limited | Administrative & support | 2020 |
| BYB FD Support Ltd | Professional & scientific | 2009 |
| C & C Teisar Property Ltd | Real estate | 2002 |
| C P Civil Engineering (UK) Limited | Construction | 2012 |
| Cadwal Construction Ltd | Construction | 2013 |
| Calon Care Limited | Administrative & support | 2008 |
| Calon Lodge (UK) Ltd | Hospitality | 2021 |
| Calon People Consulting Limited | Professional & scientific | 2023 |
| Calon Property Holdings Ltd | Real estate | 2026 |
| CAM Investment Properties Ltd | Real estate | 2025 |
| Cameron Nelson Racing Ltd | Arts & recreation | 2021 |
| Candour Healthcare Limited | Health & social care | 2024 |
| Caravanmaster (South Wales) Limited | Wholesale & retail | 2004 |
| Carbon Free Solar Limited | Professional & scientific | 2024 |
| Cardiff Audio Visual Ltd | Administrative & support | 2026 |
| Cardiff Commercials Plant and Machinery Limited | Wholesale & retail | 2024 |
| Cardiff Giant DTC Limited | Information & communication | 2023 |
| Cardiff Giant Holdings Limited | Financial services | 2023 |
| Cardiff Giant Media Ltd | Information & communication | 2025 |
| Cardiff Giant Ventures Limited | Information & communication | 2019 |
| Carel Construction & Landscaping Ltd | Construction | 2018 |
| Caroline Kelly Accountancy & Consulting Limited | Professional & scientific | 2015 |
| Castellum Risk Management Group Ltd | Administrative & support | 2020 |
| Cater-Equip Ltd | Manufacturing | 2005 |
| Catherine Lewis Design Limited | Professional & scientific | 2021 |
| Cc&B Events Ltd | Administrative & support | 2021 |
| CD Jones Ltd | Professional & scientific | 2016 |
| CEF Consultancy Solutions Limited | Other services | 2021 |
| Cefnder Properties Limited | Real estate | 2022 |
| Celtic Community Services Limited | Health & social care | 2008 |
| Celtic Doors Ltd. | Manufacturing | 2012 |
| Celtic Frozen Drinks Ltd | Wholesale & retail | 2014 |
| Celtic Grove Properties Limited | Real estate | 2025 |
| Change Your Future Recruitment Limited | Administrative & support | 2022 |
| Channel Drylining Ltd | Construction | 2016 |
| Channel Property and Maintenance Ltd | Real estate | 2021 |
| Chaos Crazy Carts Ltd | Administrative & support | 2026 |
| Charisma Hair Ltd | Other services | 2025 |
| Chartercraft Limited | Professional & scientific | 2010 |
| Chienergy Ltd | Professional & scientific | 2018 |
| Chill Properties Limited | Real estate | 2018 |
| Chris Skinley Aviation Ltd | Manufacturing | 2024 |
| Cinnamore Ltd | Hospitality | 2025 |
| CJ Sports Therapy Ltd | Health & social care | 2024 |
| CK Sporthomes Ltd | Manufacturing | 2021 |
| Cleanmate Limited | Administrative & support | 2015 |
| Clearly Scientific Ltd | Professional & scientific | 2019 |
| Clenergy EV Ltd | Information & communication | 2017 |
| Clevr Performance Marketing Ltd | Professional & scientific | 2025 |
| Cloud Formations Group Limited | Arts & recreation | 2020 |
| CME Construction Ltd | Construction | 2019 |
| CMW Bikes Ltd | Wholesale & retail | 2025 |
| CNM Lettings Ltd | Real estate | 2024 |
| Co Elevate Consulting Limited | Professional & scientific | 2026 |
| Coco Gelato Holdings Ltd | Manufacturing | 2014 |
| Coed CAE Properties Limited | Real estate | 2015 |
| Coedwig Capital Ltd | Real estate | 2022 |
| Coedwig Group Ltd | Financial services | 2024 |
| Comasi Group Ltd | Financial services | 2021 |
| Company Support Services Ltd | Professional & scientific | 2020 |
| Compass Coaching and Consulting Ltd | Professional & scientific | 2005 |
| Composite Doors Bristol Limited | Construction | 2022 |
| Concrete Canvas Group Limited | Manufacturing | 2011 |
| Concrete Canvas Kyrgyzstan Limited | Manufacturing | 2025 |
| Concrete Canvas Limited | Manufacturing | 2005 |
| Concrete Canvas Properties Limited | Manufacturing | 2013 |