| DCS Properties (South Wales) Limited | Real estate | 2018 |
| Deacon Innovations Ltd | Manufacturing | 2016 |
| Deanjc Engineering Limited | Manufacturing | 2026 |
| Deep Mind Electronics Limited | Manufacturing | 2024 |
| Deere and SON Limited | Real estate | 2017 |
| DFA Autos Limited | Wholesale & retail | 2026 |
| Dibble Aviation Ltd | Manufacturing | 2016 |
| Digital Mapping and Survey Limited | Information & communication | 2009 |
| Direct Vehicle Sales (Wales) Ltd | Wholesale & retail | 2021 |
| Divine Light Readings Ltd | Other services | 2025 |
| DJC Engineering Services Ltd | Manufacturing | 2023 |
| DJR Aviation Ltd | Manufacturing | 2019 |
| DJR Technical Ltd | Manufacturing | 2019 |
| DJS Watson Engineering Limited | Manufacturing | 2023 |
| DL & C Engineering Limited | Manufacturing | 2017 |
| Dolen Fideo CYF | Information & communication | 2026 |
| Don'T Panic Productions Ltd | Information & communication | 2016 |
| Dorma Construction Bridgend Limited | Construction | 2012 |
| Dost Catering Ltd | Hospitality | 2018 |
| DR Morgan Psychological Services Ltd | Health & social care | 2024 |
| Dragon Heating Engineers Ltd | Transport & logistics | 2013 |
| Dragonstone Venetian Plastering Limited | Manufacturing | 2026 |
| Driven Personal Hire Limited | Transport & logistics | 2003 |
| Driving Vision Group Ltd | Other services | 2017 |
| DRJ Valeting Limited | Administrative & support | 2024 |
| Durlucia Investments Limited | Administrative & support | 2007 |
| Durlucia Properties Ltd | Real estate | 2024 |
| Dymond Rental Management & Development Ltd | Construction | 2024 |
| E&J Aerotech Limited | Manufacturing | 2016 |
| E.P Urban Properties Ltd | Households | 2026 |
| Easy Aero Services Limited | Manufacturing | 2012 |
| Echo Dance C.I.C. | Arts & recreation | 2025 |
| Ecka Granules (UK) | | 2001 |
| Eco 2022 Stoves Limited | Construction | 2020 |
| Eco Free Water Ltd | Wholesale & retail | 2024 |
| Eco Green Exterior Cleaning Ltd | Administrative & support | 2021 |
| Eco Liquids Limited | Administrative & support | 2018 |
| Eddie Rabaiotti and Sons Limited | Extraterritorial | 2015 |
| Edit Comps Limited | Manufacturing | 2024 |
| Edka Ltd | Wholesale & retail | 2017 |
| EG Management Consultancy Limited | Professional & scientific | 2023 |
| Electramotive Limited | Manufacturing | 2020 |
| Electroacoustic Design Ltd | Professional & scientific | 2011 |
| Elgol Developments Ltd | Construction | 2007 |
| Elite Dragon Roofing, Rendering & Plastering Services Ltd | Construction | 2025 |
| Ellison Retail Services Limited | Administrative & support | 2021 |
| Embrace Properties Ltd | Real estate | 2021 |
| Embryx Corporation Ltd | Wholesale & retail | 2026 |
| Emerald Couture Limited | Manufacturing | 2021 |
| Epilepsy Matters Cymru Ltd | Education | 2022 |
| Esplanade Porthcawl Limited | Hospitality | 2006 |
| Eurof Davies Building and Roofing Contractors Limited | Construction | 2003 |
| Evans Funeralcare Limited | Other services | 2026 |
| Expert LMS Limited | Education | 2021 |
| Ezvend Ltd | Wholesale & retail | 2026 |
| F & G Property Developments Ltd | Real estate | 2020 |
| Facilities Management Surveys Limited | Administrative & support | 2016 |
| Falcon Mechanical Ltd | Construction | 2024 |
| Familia DE LA Noche Theatre Company Ltd | Arts & recreation | 2014 |
| Fathom Engineering Ltd | Manufacturing | 2018 |
| Fghpropertymanagement Limited | Real estate | 2023 |
| FHU Limited | Manufacturing | 2026 |
| Fisher Technical Ltd | Administrative & support | 2016 |
| Fishspire Limited | Transport & logistics | 2012 |
| Fleurbeck Limited | Manufacturing | 2015 |
| Fone Heaven Limited | Information & communication | 2025 |
| Fourth Floor Ltd | Manufacturing | 2026 |
| Foxsmiths Law Limited | Professional & scientific | 2019 |
| Francis Davies and Partners Ltd | Professional & scientific | 2011 |
| Frank Aerotech Limited | Transport & logistics | 2010 |
| Fryhouse Enterprises Limited | Real estate | 2006 |
| FUN Fair Sites Limited | Real estate | 1956 |
| Fuscle Limited | Manufacturing | 2022 |
| Fusion Business Insight Ltd | Information & communication | 2018 |
| Future Motive Ltd | Wholesale & retail | 2019 |
| Futurify Dynamics Limited | Information & communication | 2024 |
| G RAD Services Limited | Administrative & support | 2004 |
| G.B.E. Management Services Limited | Real estate | 1992 |
| Gabriella Driver Limited | Wholesale & retail | 2015 |
| Game Plan T & R Ltd | Real estate | 2020 |
| GAR Aviation Ltd | Professional & scientific | 2022 |
| Garfield Richards Engineering Co. Limited | Manufacturing | 2005 |
| Garmin Properties Ltd | Real estate | 2018 |
| Gavel Down Properties Ltd | Real estate | 2019 |
| Gazbun Limited | Construction | 2015 |
| GCO Aviation Services Ltd | Manufacturing | 2019 |
| GCT Property Ltd | Real estate | 2019 |
| GEA Consulting Limited | Professional & scientific | 2019 |
| Gemac Developments Limited | Real estate | 2017 |
| Gemstone Scenery and Furniture Ltd | Arts & recreation | 2019 |
| GES Engineering Limited | Professional & scientific | 2018 |
| GG Construction Ltd | Construction | 2020 |
| GG Prop Co Limited | Real estate | 2019 |
| GHA Consult Limited | Professional & scientific | 2019 |
| GHI Properties Ltd | Real estate | 2020 |
| Gibbon Engineering Services Ltd | Transport & logistics | 2025 |
| Gibbs Technical Solutions Limited | Manufacturing | 2015 |
| Gilkes Aerospace Limited | Manufacturing | 2019 |
| Gingineering UK Limited | Manufacturing | 2018 |
| Glan Road Flats Management Limited | Real estate | 1989 |