| Guangdong 2U (UK) Ltd | Real estate | 2004 |
| Guard Management Systems Ltd | Information & communication | 2023 |
| Guestly AI Ltd | Information & communication | 2025 |
| Guesture Property Management Ltd | Hospitality | 2018 |
| Guided Battlefield Tours Limited | Administrative & support | 2008 |
| Guilfoyle Sage Limited | Professional & scientific | 2008 |
| Guilfoyle Sage LLP | | 2008 |
| Gulbasi NPT Ltd | Hospitality | 2025 |
| Gumgauge Ltd | Manufacturing | 2024 |
| Gunda Flower Boutique Ltd | Other services | 2021 |
| Gunnar Management Ltd. | Arts & recreation | 2018 |
| Gunnell Group Ltd | Financial services | 2024 |
| Gunville Stores Ltd | Wholesale & retail | 2024 |
| Gupta & Gupta Limited | Health & social care | 2012 |
| Gupta Prime Estates Ltd | Real estate | 2026 |
| Gupta Smile Ltd | Health & social care | 2026 |
| Gupta Ventures Capital Ltd | Financial services | 2026 |
| Gurit Material Systems (UK) Limited | Manufacturing | 2002 |
| Gurkha Stay Ltd | Hospitality | 2022 |
| Gurmeet Singh Grewal Property Ltd | Households | 2024 |
| Gurtaran Misson Ltd | Real estate | 2020 |
| GUS Jones (Jewellers) Limited | Wholesale & retail | 1976 |
| Guvnors (Shropshire) Ltd | Other services | 2019 |
| Gwashie Ltd | Health & social care | 2024 |
| Gwawr Haines Limited | Hospitality | 2017 |
| Gwent Aluminium & Upvc Windows Ltd | Wholesale & retail | 2011 |
| Gwent Arts in Health (Garth) | Health & social care | 2004 |
| Gwent Association of Voluntary Organisations | Other services | 2005 |
| Gwent Auto Spares Ltd | Wholesale & retail | 2020 |
| Gwent Ballet Theatre Limited | Arts & recreation | 1990 |
| Gwent Car Sales Ltd | Wholesale & retail | 2014 |
| Gwent Care Ltd | Other services | 2018 |
| Gwent Centre for Community Development CBC | Information & communication | 2025 |
| Gwent Civil Engineering Limited | Construction | 1998 |
| Gwent Domiciliary Care Services Limited | Health & social care | 2023 |
| Gwent ENT Services Limited | Health & social care | 2013 |
| Gwent Enviro Waste Ltd | Water & waste | 2024 |
| Gwent Garden Designs Limited | Other services | 1975 |
| Gwent Holdings Limited | Real estate | 2016 |
| Gwent Karting Limited | Arts & recreation | 1995 |
| Gwent Land Limited | Real estate | 2016 |
| Gwent Logistics Ltd | Transport & logistics | 2026 |
| Gwent Medical Ltd | Health & social care | 2022 |
| Gwent Property Developments Ltd | Real estate | 2021 |
| Gwent Recovery’S Ltd | Transport & logistics | 2025 |
| Gwent Travel Solutions Ltd | Transport & logistics | 2022 |
| Gwent Urology Limited | Health & social care | 2018 |
| Gwent Valeting Ltd | Administrative & support | 2017 |
| Gwerthwr Limited | Wholesale & retail | 2025 |
| GWH Maintenance Limited | Administrative & support | 2025 |
| Gwill's Carpets Limited | Wholesale & retail | 1999 |
| GWJ Pulse Properties Ltd | Real estate | 2025 |
| GWS Digital Limited | Administrative & support | 2025 |
| GWS Management Limited | Households | 2016 |
| Gwyddon Automation Ltd | Professional & scientific | 2025 |
| Gwyllt Limited | Real estate | 2016 |
| Gwynedd Estates Ltd | Real estate | 2024 |
| Gymnastics Enterprises Limited | Other services | 1991 |
| Gymwash Limited | Wholesale & retail | 2022 |
| GYO Ltd | Professional & scientific | 2005 |
| H & DA Trading Limited | Wholesale & retail | 2025 |
| H & G Explosives Services Ltd. | Manufacturing | 1993 |
| H & H Engineering (South Wales) Limited | Professional & scientific | 2024 |
| H & H Engineering Blaenavon Ltd | Real estate | 1999 |
| H & H Surveyors & Valuers Ltd | Professional & scientific | 2020 |
| H & L Scaffolding Ltd | Construction | 2024 |
| H & R Optics Limited | Wholesale & retail | 2023 |
| H & T Property (Cardiff) Limited | Real estate | 2024 |
| H & V Fusion and Drilling Northern Limited | Professional & scientific | 2015 |
| H Ferreira Ltd | Health & social care | 2013 |
| H G Edwards Construction Limited | Construction | 2008 |
| H Marsh Services Ltd | Real estate | 2024 |
| H Mortgages Ltd | Financial services | 2026 |
| H R S Renovations Ltd | Construction | 2026 |
| H Squared Healthcare Assessments Ltd | Health & social care | 2023 |
| H Systems Energy Limited | Construction | 2026 |
| H Systems Renewables Limited | Construction | 2025 |
| H T Davies & Partners LLP | | 2016 |
| H&Ali Properties Limited | Real estate | 2025 |
| H&G Wootton Ltd | Other services | 2022 |
| H&M Prestige Homes Ltd | Real estate | 2025 |
| H&R Accountancy Limited | Professional & scientific | 2019 |
| H&R Accounts Services and General Admin Ltd | Professional & scientific | 2018 |
| H&S Pharmacy Ltd | Wholesale & retail | 2023 |
| H.E.A.L(Henrie Empowerment for Awareness and Life) CIC | Education | 2025 |
| H.J European Couriers Ltd | Transport & logistics | 2012 |
| H.L. Psychology Ltd | Education | 2020 |
| H.Timmis(Farms)Limited | Agriculture & fishing | 1954 |
| H.V. Taylor & SON Limited | Extraterritorial | 1973 |
| H4 WLD Limited | Professional & scientific | 2012 |
| H8TD Ltd | Arts & recreation | 2025 |
| HA Financial Solutions Limited | Professional & scientific | 2022 |
| HA Plumbing Services Ltd | Construction | 2023 |
| Habboush Medical Consultancy Ltd | Health & social care | 2015 |
| Haberdashers' West Midlands Academies Trust | Education | 2008 |
| Habib Trading Ltd | Wholesale & retail | 2021 |
| HAC Estates Ltd | Real estate | 2026 |
| Hadigate & Sons Limited | Manufacturing | 2026 |
| Hadkam Property Ltd | Real estate | 2019 |
| Haffenden Houses Limited | Real estate | 2026 |