| Brynmawr House Limited | Hospitality | 2025 |
| Brynmawr Nails Limited | Other services | 2024 |
| Brynmenyn Estates Limited | Real estate | 2000 |
| Buds to Blossoms Day Nurseries 2 Limited | Education | 2026 |
| Buds to Blossoms Day Nurseries Limited | Education | 2018 |
| Builders Force Services Ltd | Construction | 2024 |
| Bull Film and Motion Ltd | Information & communication | 2022 |
| Bunker Airsoft SW Ltd | Arts & recreation | 2023 |
| Butter's Food Ltd | Hospitality | 2025 |
| C & C Ceramics Limited | Construction | 2013 |
| C Powell & Co Limited | Wholesale & retail | 2018 |
| C&F Electrical Limited | Construction | 2020 |
| C.Pitt Services Ltd | Wholesale & retail | 2025 |
| Calmya Ltd | Real estate | 2024 |
| Candour Group Holdings Limited | Financial services | 2026 |
| Candour Talent Limited | Administrative & support | 2016 |
| Candour Talent Perms Limited | Administrative & support | 2026 |
| Candour Talent Temps Limited | Administrative & support | 2026 |
| Cardiff Business Advisers Limited | Professional & scientific | 2014 |
| Cardiff Card Show Ltd | Arts & recreation | 2025 |
| Cardio Vision Services Limited | Extraterritorial | 2024 |
| Carmel Curry Spice Ltd | Hospitality | 2025 |
| Carquest Motors Ltd | Wholesale & retail | 2024 |
| CB Commercials Limited | Wholesale & retail | 2004 |
| Cdstorage Ltd | Transport & logistics | 2026 |
| Cecen Ltd | Hospitality | 2024 |
| Central Cars (Ebbw Vale) Limited | Wholesale & retail | 2005 |
| Central FM Group Ltd. | Administrative & support | 2012 |
| Central Recruitment Solutions Ltd | Administrative & support | 2020 |
| Central Security and Fire Limited | Administrative & support | 2019 |
| Central UK Cleaning Services Ltd | Administrative & support | 2020 |
| Central UK Group Limited | Administrative & support | 2020 |
| Central UK Security Services Limited | Administrative & support | 2024 |
| Central Workforce Solutions Limited | Administrative & support | 2024 |
| CES Design and Build Ltd | Professional & scientific | 2025 |
| CG Autos Servicing and Repair Limited | Wholesale & retail | 2026 |
| Chip OFF the Old Block Ltd | Hospitality | 2022 |
| Civils 3D Ltd | Professional & scientific | 2018 |
| CJL Property Holdings Limited | Construction | 2023 |
| Cjpd Ltd | Financial services | 2023 |
| Clam's Handmade Cakes Limited | Manufacturing | 2015 |
| Clarkes Commercial Repairs Limited | Manufacturing | 2025 |
| Cnew Business Consultancy Ltd | Professional & scientific | 2012 |
| Coach Ieuan Ltd | Arts & recreation | 2024 |
| Coedcae Community Hub C.I.C. | Health & social care | 2025 |
| Coffi BAA Ltd | Hospitality | 2023 |
| Colliers MOT Centre Ltd | Wholesale & retail | 2024 |
| Combined Engineering Services Ltd | Professional & scientific | 2017 |
| Community Response Services Ltd | Administrative & support | 2025 |
| Craig Thomas Properties Ltd | Real estate | 2019 |
| CRC Scaffolding Ltd | Construction | 2015 |
| Creative SET Construction Ltd | Arts & recreation | 2023 |
| Creative Shoes 4U Ltd | Wholesale & retail | 2025 |
| Creedale Limited | Real estate | 2005 |
| Crown Chakra Limited | Other services | 2018 |
| CS & CLM (Commercial) Ltd | Real estate | 2022 |
| CS & CLM Ltd | Construction | 2015 |
| CS Pubs & Bars Ltd | Hospitality | 2025 |
| CWM Boxing Club Limited | Arts & recreation | 2019 |
| Cwmdraw MOT Centre Ltd | Wholesale & retail | 2020 |
| Cwmhaus Ltd | Manufacturing | 2022 |
| Cyberstyle Profiles Ltd | Information & communication | 2025 |
| D T Civils Limited | Construction | 2002 |
| D.D. Concrete Limited | Manufacturing | 1988 |
| D.G.J. Planning Limited | Construction | 2001 |
| Daff and Dill Ltd | Hospitality | 2020 |
| Damian Jones Consultancy Limited | Construction | 2020 |
| DAN ROB Electrical Services Ltd | Construction | 2020 |
| Danielle Jones Property Limited | Real estate | 2023 |
| Darryl Steed Tiling Limited | Construction | 2024 |
| Davies & Lewis Development Limited | Construction | 2017 |
| Davies Home Store Ltd | Wholesale & retail | 2019 |
| Davies Mechanical Engineering Ltd | Professional & scientific | 2022 |
| Dbit Systems Ltd | Information & communication | 2014 |
| Dear Darcie Designs Ltd | Manufacturing | 2022 |
| Demark Consulting Ltd | Professional & scientific | 2022 |
| Desiva Investments Limited | Real estate | 1999 |
| Dexter Property Ltd | Real estate | 2024 |
| Dezsa Ltd | Wholesale & retail | 2024 |
| Diack Ltd | Construction | 2002 |
| Dinosaurs Direct Ltd | Wholesale & retail | 2020 |
| DJ Fire Solutions Limited | Public administration | 2025 |
| DJJ Capital Limited | Real estate | 2026 |
| DJJ Group Limited | Financial services | 2026 |
| DOC Surveying Limited | Professional & scientific | 2024 |
| Doleq Carpets (South Wales) Ltd | Wholesale & retail | 2011 |
| Doltra Events Ltd | Hospitality | 2026 |
| DP Auto's Car & Commercial Repairs Ltd | Wholesale & retail | 2019 |
| Dpe.Edmunds Utilities Ltd | Construction | 2026 |
| DR David Baker Limited | Health & social care | 2017 |
| Dragon Continuforms Limited | | 1980 |
| Drvn Social Ltd | Professional & scientific | 2023 |
| DS Bar Group Ltd | Hospitality | 2018 |
| DSV Investments Ltd | Extraterritorial | 2020 |
| DT Technical Solutions Limited | Real estate | 2010 |
| DVS Health & Fitness Limited | Arts & recreation | 2025 |
| DW Groundwork & Construction Ltd | Construction | 2020 |
| DZG Ltd | Arts & recreation | 2024 |
| E Jones Consulting Limited | Professional & scientific | 2025 |
| E-Venture Cycles Cymru Ltd | Wholesale & retail | 2023 |