| DMG Books Ltd | Information & communication | 2022 |
| DMS Saleswizz Ltd | Wholesale & retail | 2023 |
| DR Nina Medical & Aesthetics Ltd | Health & social care | 2025 |
| Dragon Decor Ltd | Construction | 2013 |
| Draig Goch Holdings Ltd | Arts & recreation | 2026 |
| Drillingworth Ltd | Hospitality | 2014 |
| DRIVE2BUY UK Ltd | Wholesale & retail | 2025 |
| Drym Developments Ltd | Energy | 2015 |
| Dudley Autos Limited | Wholesale & retail | 2018 |
| Duffryn Enterprises Limited | Wholesale & retail | 1985 |
| Duffryn Estates & Facilities Advisers Ltd | Administrative & support | 2010 |
| Duraseal Limited | Construction | 2001 |
| Duraseal Roofing & Maintenance Ltd | Administrative & support | 2010 |
| Dust & Shine Cleaning Services Ltd | Administrative & support | 2021 |
| Dyfan Jones Limited | Arts & recreation | 2010 |
| E Q Camperparts Limited | Wholesale & retail | 2021 |
| E&C Services Ltd | Wholesale & retail | 2020 |
| E-Learning Ltd | Education | 2025 |
| E. Thomas & Williams Limited | Manufacturing | 1907 |
| Easy Panels Holdings Ltd | Financial services | 2024 |
| Easy Panels Ltd | Wholesale & retail | 2022 |
| ECB Scaffolding Ltd | Construction | 2025 |
| Ecoserv Solar Maintenance Ltd | Administrative & support | 2025 |
| ECS Mechanical Servicing Ltd | Manufacturing | 2019 |
| Edmunds Innovations Ltd | Wholesale & retail | 2018 |
| Edmunds Property & Letting Ltd | Real estate | 2021 |
| Eftec Limited | Manufacturing | 1978 |
| Egni AMF CYF | Real estate | 2023 |
| EJG Rail Ltd | Other services | 2025 |
| ELB Property Lettings Limited | Real estate | 2024 |
| Electraplus Contracting Ltd | Construction | 2016 |
| Electrical Bitz Ltd | Wholesale & retail | 2009 |
| Elegant Infusions Ltd | Wholesale & retail | 2025 |
| Elias Smith Ltd | Information & communication | 2022 |
| Elite Animal Feeds Ltd | Wholesale & retail | 2025 |
| Elite Barbers 11B Aberdare Ltd | Other services | 2026 |
| Ellbeck Limited | Financial services | 2017 |
| Ellis Eggs Limited | Wholesale & retail | 2011 |
| ELM Properties (Aberdare) Limited | Households | 1993 |
| Emma Jayne Cake Design Ltd | Education | 2021 |
| Encor! Ltd | Arts & recreation | 2021 |
| Enersyst Limited | Energy | 2014 |
| Enhanced by Madison Grace Ltd | Wholesale & retail | 2026 |
| Enrm Ltd | Other services | 2023 |
| Entangled Positions Ltd | Administrative & support | 2021 |
| Entry Specialists Limited | Administrative & support | 2022 |
| ERS Networks Ltd | Construction | 2025 |
| Esgyn Developments SW Ltd | Construction | 2025 |
| ET Barber Limited | Other services | 2020 |
| Ethan Welsh Property Ltd | Real estate | 2025 |
| Eurotech Balcony Systems Ltd | Construction | 2018 |
| Eurotech Power Systems Ltd | Construction | 2020 |
| Eurotech Roofing Limited | Construction | 2011 |
| EV Express Limited | Transport & logistics | 2018 |
| Excalibur Kennels Ltd | Agriculture & fishing | 2018 |
| Exellevate Ltd | Professional & scientific | 2024 |
| Exellevate Models Ltd | Professional & scientific | 2025 |
| Ezirend Ltd | Construction | 2017 |
| Fabian Way Ltd | Wholesale & retail | 2022 |
| Fabuloushair&Lash Limited | Other services | 2025 |
| Fairleap Developments Ltd | Construction | 2020 |
| Fairleap Limited | Construction | 2012 |
| Fantasian Toy Store Limited | Wholesale & retail | 2025 |
| Farelandscaping and Groundwork Ltd | Construction | 2025 |
| Farley & Co Property Ltd | Real estate | 2025 |
| Favorite GT Limited | Hospitality | 2023 |
| Femvic Services Limited | Hospitality | 2018 |
| Fennica Dental Laboratory Ltd | Manufacturing | 2019 |
| Fern Builders Ltd | Construction | 2026 |
| Ffcs Hire and Equipment Ltd | Administrative & support | 2016 |
| Fflur Limited | Wholesale & retail | 2020 |
| Fingers and Tums Ltd | Wholesale & retail | 2022 |
| First Light Records Limited | Information & communication | 2005 |
| Fishy Ltd | Hospitality | 2025 |
| Fletcher Groundworks & Civils Ltd | Construction | 2026 |
| Florence Healthcare Limited | Administrative & support | 2014 |
| FONESOLUTIONS1 Limited | Other services | 2023 |
| Food Adventure Social Enterprise Ltd | Hospitality | 2019 |
| Form-Fix Concrete Solutions Ltd | Construction | 2014 |
| Foundress Law & Co Limited | Professional & scientific | 2025 |
| FOX Electrical Engineering Ltd | Construction | 2009 |
| Fraser & SON Holdings Ltd | Construction | 2021 |
| Freemans Leisure Limited | Arts & recreation | 2026 |
| Furwood Developments Limited | Construction | 2019 |
| FW Carpentry Ltd | Construction | 2026 |
| G Howells Carpentry and Construction Ltd | Manufacturing | 2023 |
| G James Electrical Limited | Construction | 2005 |
| G Johal Investments Ltd | Real estate | 2022 |
| G Warton Limited | Real estate | 2024 |
| G-Fab Welding and Fabrication Ltd | Manufacturing | 2010 |
| G. Walters (Holdings) Limited | Professional & scientific | 1992 |
| G. Walters (Leasing) Limited | Financial services | 1999 |
| GA 2025 Limited | Professional & scientific | 2025 |
| Gaby & Alex External Insulation Ltd | Construction | 2021 |
| Gain Access Locksmiths Ltd | Wholesale & retail | 2024 |
| GAP Internals Ltd | Construction | 2015 |
| GAP Investment Properties Ltd | Real estate | 2018 |
| Gardiner Davies Limited | Manufacturing | 2015 |
| Gareth Hippsley Designs CYF | Professional & scientific | 2018 |
| GCE Engineering Limited | Construction | 2014 |