| Clearline(Uk) Ltd | Agriculture & fishing | 2014 |
| Clement Clarke International Limited | Manufacturing | 1942 |
| Clickabrix Ltd | Information & communication | 2011 |
| Codinsol Ltd | Wholesale & retail | 2023 |
| Collinspropertygroup Ltd. | Construction | 2021 |
| Complete Background Screening Ltd | Other services | 2005 |
| Complete Co-Packing Services Limited | Manufacturing | 2015 |
| Contact Marketing Limited | Professional & scientific | 2002 |
| Cooks Company and Befriending Service Ltd | Health & social care | 2025 |
| Coomer's Developments Limited | Construction | 2025 |
| Coomer's Properties Limited | Real estate | 2025 |
| Coulstock Collins Limited | Professional & scientific | 2025 |
| Craig Wright Consultancy Ltd | Information & communication | 2025 |
| CWM Cynon Properties Ltd | Real estate | 2018 |
| CY Electrical Limited | Construction | 2024 |
| Cylch Meithrin Seren Fach | Education | 2015 |
| Cymoedd Property Services Ltd | Real estate | 2018 |
| Cynon Scaffolding Services Limited | Construction | 2023 |
| Cynon Wills and Estate Planning Ltd | Professional & scientific | 2015 |
| D and L Autoworks Ltd | Wholesale & retail | 2023 |
| D B Mouldings Limited | Manufacturing | 1999 |
| D C L Electrics Ltd | Construction | 2021 |
| D Trow Properties Ltd | Real estate | 2025 |
| D Williams Scaffolding Ltd | Construction | 2022 |
| D&G Holdings SW Limited | Financial services | 2022 |
| D&R Rendering Ltd | Construction | 2022 |
| D.Trow Carpentry Ltd | Construction | 2021 |
| Damp Proofing SW Ltd | Construction | 2023 |
| DAN Rail Welding Ltd | Construction | 2020 |
| Danoom Wellness Ltd | Arts & recreation | 2023 |
| Dark Skies Cinema Ltd | Professional & scientific | 2022 |
| Darran LAS Community Building | Information & communication | 2007 |
| Darran LAS Environmental Group Limited | Education | 2007 |
| Davies Decorating Group Ltd | Construction | 2026 |
| Dazzle-Cymru CIC | Professional & scientific | 2025 |
| DB Manufacturing Ltd | Manufacturing | 2024 |
| DC-3IP Limited | Information & communication | 2024 |
| Dean Phillips Plastering Ltd | Construction | 2021 |
| Dean Phillips Properties Ltd | Real estate | 2026 |
| Decorative Drives and Patios Limited | Construction | 2016 |
| Delicate Foods Station Ltd | Hospitality | 2025 |
| Delta Washrooms Ltd | Construction | 2019 |
| Dene Healthcare Limited | Wholesale & retail | 2005 |
| Designer Fires Ltd | Wholesale & retail | 2019 |
| DFO Electrical Ltd | Construction | 2014 |
| DHH Commercial Limited | Construction | 2024 |
| Diamond Design Interiors Building and Maintenance Limited | Construction | 2023 |
| Dilwyn Properties Ltd | Real estate | 2026 |
| Direct 2 AI Limited | Information & communication | 2025 |
| Dmasquared Ltd | Real estate | 2024 |
| Dragoncog Interactive Ltd. | Information & communication | 2022 |
| DRS Pizza Ltd | Hospitality | 2025 |
| DSR Groundworks Ltd | Construction | 2015 |
| Dumelow International Limited | Wholesale & retail | 1996 |
| Dumelow Tractors Limited | Wholesale & retail | 2019 |
| Dunning Property Limited | Real estate | 2025 |
| Dxnrendering Ltd | Construction | 2022 |
| Dycon Power Solutions Limited | Manufacturing | 2014 |
| E&A Coastal Properties Ltd | Hospitality | 2025 |
| Ebony & Ivory Wedding Cars Ltd | Administrative & support | 2012 |
| Ebzon Onestop Solutions Ltd | Wholesale & retail | 2021 |
| Eco-Explore Community Interest Company | Professional & scientific | 2010 |
| Edutab Consult Ltd | Information & communication | 2025 |
| EJC Rail Ltd | Construction | 2016 |
| Ekvarta Ltd | Health & social care | 2026 |
| Electric Bike Wales Limited | Wholesale & retail | 2022 |
| Elevate by ASH & GEM Ltd | Real estate | 2025 |
| Elisg Property Ltd | Real estate | 2020 |
| Elite Country Homes Limited | Real estate | 2015 |
| EME Property Limited | Real estate | 2025 |
| Emily's World Limited | Administrative & support | 2021 |
| Emmasphere Limited | Administrative & support | 2025 |
| Ergo Events Ltd | Hospitality | 2020 |
| Escapade 42 Ltd | Real estate | 2023 |
| Evanhalli Ltd | Construction | 2019 |
| Express Pumps Ltd | Manufacturing | 2008 |
| FD & LT Properties Ltd | Real estate | 2024 |
| Fernhill and Glenboi Community Centre | Health & social care | 2018 |
| FF Space Development Ltd | Construction | 2019 |
| Fftbh Ltd | Real estate | 2023 |
| Final Frontier Space Holdings Ltd | Construction | 2020 |
| Finbi Design Limited | Professional & scientific | 2017 |
| First for Gifts Ltd | Wholesale & retail | 2021 |
| Fitness Addicts Limited | Health & social care | 2024 |
| Flexicare (Group) Limited | Financial services | 2014 |
| Flexicare Medical Limited | Manufacturing | 1989 |
| Flexicare Ventures Limited | Financial services | 2020 |
| Form X Group Ltd | Manufacturing | 2023 |
| Formation Aesthetics Ltd | Other services | 2025 |
| G & C Building and Plastering Ltd | Construction | 2012 |
| G & N Commerical Repairs Ltd | Wholesale & retail | 2026 |
| G Best Partner Limited | Hospitality | 2016 |
| G Squared Property Ltd | Real estate | 2021 |
| G Squared Surveying Ltd | Professional & scientific | 2017 |
| G&M Waters Drylining Limited | Construction | 2023 |
| GAP Motorcycles Limited | Wholesale & retail | 2023 |
| Gasco Ltd | Construction | 1994 |
| Gazi Mart Ltd | Wholesale & retail | 2026 |
| GD Meats (Mountain ASH) Ltd | Wholesale & retail | 2012 |
| Geotron Properties Ltd | Real estate | 2021 |