| Craig Sibley Limited | Real estate | 2003 |
| Craig Taylor Plumbing Limited | Construction | 2019 |
| Craighead Kellas Limited | Information & communication | 2024 |
| CRE Care Ltd. | Health & social care | 2023 |
| Creadigol Colwyn Creative CIC | Professional & scientific | 2025 |
| Creamer Holding Group Limited | Financial services | 2026 |
| Creative Adventures Conwy CIC | Arts & recreation | 2024 |
| Crescent Court (Llandudno) Limited | Real estate | 1974 |
| CSS Drainage NW Ltd | Water & waste | 2026 |
| CT Events Ltd | Other services | 2023 |
| Cummings Web Services Limited | Information & communication | 2022 |
| Curtain Magic Limited | Wholesale & retail | 2012 |
| Curvasure Limited | Professional & scientific | 2003 |
| CWM Campers Ltd | Professional & scientific | 2019 |
| CX Controls Limited | Professional & scientific | 2012 |
| Cybermaxio Game Ltd | Information & communication | 2023 |
| Cybersec NW Ltd | Information & communication | 2021 |
| Cyclo-Ssage Limited | Wholesale & retail | 2007 |
| Cynad Ltd | Professional & scientific | 2022 |
| D & I Lewis Properties Limited | Real estate | 2026 |
| D Blake Group Limited | Financial services | 2024 |
| D&J Home Solutions Ltd | Real estate | 2024 |
| D2D Sales Ltd | Administrative & support | 2011 |
| D4-COMMERCIAL Diving Services Limited | Manufacturing | 2014 |
| Daniels Plant Hire Ltd | Construction | 2020 |
| Danilton Management Company Limited | Households | 2025 |
| Darius Menswear Ltd | Wholesale & retail | 2022 |
| Darrel Water Services Ltd | Construction | 2024 |
| Data Visualised Limited | Information & communication | 2019 |
| Davize Publishing Ltd | Information & communication | 2022 |
| Debrett Installations Limited | Construction | 2019 |
| Debtfair Ltd | Professional & scientific | 2010 |
| Deesolve Limited | Real estate | 2023 |
| Deganwy Court (Deganwy) Management Company Limited | Households | 2007 |
| Deli Catering (North Wales) Limited | Hospitality | 2019 |
| Delta Fire & Security Limited | Administrative & support | 2004 |
| Dermalight Clinic Ltd | Other services | 2025 |
| Design & Build NW Limited | Real estate | 2025 |
| Desire Code Limited | Administrative & support | 2016 |
| Developing a Caring Wales Ltd | Health & social care | 2010 |
| Diamond Nails Colwyn Bay Ltd | Other services | 2024 |
| Diva's and Dude's Salon Limited | Other services | 2018 |
| Diverse Arts Limited | Arts & recreation | 2001 |
| Diverse Excellence Cymru Ltd | Health & social care | 2009 |
| DLX Solutions Group Limited | Information & communication | 2026 |
| DM Goodwin Plastering Limited | Construction | 2012 |
| DMC Ventures Limited | Administrative & support | 2019 |
| DML Consultancy Ltd | Construction | 2024 |
| Dolgoch Properties CYF | Real estate | 2025 |
| Dolphin Court Management Company (Colwyn Bay) Limited | Households | 1974 |
| Doofenshmirtz Evil Incorporated Limited | Wholesale & retail | 2020 |
| Doran Construction Ltd | Construction | 2023 |
| Doran Lettings & Management Limited | Real estate | 2026 |
| Double W Worldwide Ltd | Professional & scientific | 2020 |
| Dowdall Building Contractors Ltd | Construction | 2021 |
| Dragon Investment Managers Ltd | Financial services | 2001 |
| Dragon Properties (Wales) Limited | Real estate | 2005 |
| Dragon Renovations Ltd | Construction | 2019 |
| Dragon Rope Access Limited | Other services | 2020 |
| Dragon Security and Electrical Ltd | Administrative & support | 2010 |
| Dragon Sports Therapy Ltd | Health & social care | 2011 |
| Drive Revive Limited | Administrative & support | 2024 |
| DSG Medical Limited | Health & social care | 2022 |
| DSO Easy Shop Limited | Wholesale & retail | 2023 |
| DY AIM Ltd | Professional & scientific | 2024 |
| DYL Parry CYF | Information & communication | 2022 |
| Dynasty 99 Limited | Hospitality | 2023 |
| E Poppleton Group Ltd | Financial services | 2023 |
| E Poppleton Holdings Ltd | Financial services | 2018 |
| E Poppleton Properties Ltd | Financial services | 2023 |
| East EAT 888 Ltd | Hospitality | 2025 |
| Eclipse Caravans Limited | Professional & scientific | 2019 |
| Eclipse Consultancy Management Limited | Professional & scientific | 2024 |
| Eclipse Leisure Group Limited | Hospitality | 2020 |
| Eco Technic Engineering Limited | Professional & scientific | 2010 |
| Ecolets Limited | Construction | 2005 |
| Edge Architects NW Ltd | Professional & scientific | 2021 |
| EGM Limited | Construction | 2020 |
| EH Consultancy Services Limited | Professional & scientific | 2023 |
| Eifion Evans Limited | Construction | 2019 |
| EL Elite Ltd | Wholesale & retail | 2024 |
| Eldon Mark Properties Ltd | Arts & recreation | 2026 |
| Elite Landscaping and Construction Ltd | Construction | 2018 |
| Elite Plumbing & Heating Solutions (NW) Limited | Construction | 2018 |
| Elite Specialist Coatings Ltd | Extraterritorial | 2020 |
| Ellesmere Road Apartments Management Company Limited | Households | 2012 |
| Ellis Renewables (NW) Ltd | Professional & scientific | 2024 |
| ELM Stone Investments Ltd | Real estate | 2025 |
| Elmhurst Transport Limited | Transport & logistics | 1983 |
| Elmwood Estates Limited | Real estate | 2026 |
| Emmac&Dc Limited | Hospitality | 2026 |
| Enervolv Ltd. | Energy | 2016 |
| Enhanced Healthcare Solutions Limited | Health & social care | 2020 |
| ENTERTAINMENT12 Ltd | Arts & recreation | 2022 |
| Envi ME Aesthetics Ltd | Other services | 2024 |
| EPH Multitrade Limited | Construction | 2007 |
| Epic Ghost Music Publishing Limited | Information & communication | 2019 |
| Erca Services Ltd | Education | 2025 |
| ERF 2027 Limited | Professional & scientific | 2026 |
| Erskine Rentals Ltd | Real estate | 2022 |