| GUL Associates Ltd | Administrative & support | 2020 |
| Gulate Limited | Arts & recreation | 1982 |
| Gunina Investments Limited | Real estate | 2019 |
| Guntower Games Limited | Other services | 2023 |
| Guri Plumbing & Heating Ltd | Construction | 2023 |
| Gurukrupa Builders & Decorators Ltd | Construction | 2026 |
| Gustoso London Ltd | Hospitality | 2024 |
| GUY M Webster Limited | Health & social care | 2008 |
| GV Prospect Ltd | Construction | 2016 |
| GW Wealth Ltd | Financial services | 2018 |
| GWS Communication Limited | Information & communication | 2013 |
| GWS Services Limited | Extraterritorial | 2007 |
| Gzim Construction Ltd | Construction | 2017 |
| GZM Motors Ltd | Wholesale & retail | 2025 |
| H & HEM News Limited | Wholesale & retail | 2010 |
| H & J Foods Limited | Wholesale & retail | 2003 |
| H & S Clothing Ltd | Manufacturing | 2017 |
| H a C G Consultancy Ltd | Other services | 2013 |
| H and S Imaging Limited | Health & social care | 2013 |
| H D UX Consultancy Ltd | Information & communication | 2014 |
| H Khairy Limited | Health & social care | 2010 |
| H N D Partners Limited | Professional & scientific | 2020 |
| H R Parsons & Sons (Butchers) Ltd | Wholesale & retail | 2013 |
| H S 9 London Ltd | Administrative & support | 2025 |
| H&A Gaming Limited | Wholesale & retail | 2019 |
| H&H Roofing Specialists Limited | Administrative & support | 2018 |
| H&R Consultancy Services Ltd | Professional & scientific | 2022 |
| H&S Property Signs Limited | Administrative & support | 2025 |
| H-Etf Limited | Information & communication | 2012 |
| H.D Real Estate (UK) Limited | Construction | 2018 |
| H.F. Search Ltd | Administrative & support | 1999 |
| H.F.S.S.S. Ltd | Education | 2005 |
| H.I. Salon Ltd | Other services | 2023 |
| H.K. Sharma Consulting Limited | Health & social care | 2009 |
| H.L.S.Properties Limited | Real estate | 1963 |
| H.L.Simons(Properties)Limited | Real estate | 1961 |
| H20 Hair Limited | Other services | 2009 |
| H2O Consulting Ltd | Professional & scientific | 2020 |
| H3K Construction Limited | Construction | 2024 |
| H5 Property Advisors Ltd | Professional & scientific | 2021 |
| HA Research & Consultancy Ltd | Other services | 2025 |
| Hacken Consulting Limited | Information & communication | 2001 |
| Hackroom Limited | Wholesale & retail | 1996 |
| Haddon Property Enterprises Limited | Real estate | 2007 |
| Hadenbase Limited | Real estate | 1985 |
| Hadham Van Sales Limited | Transport & logistics | 2008 |
| Hadley Bourne Freehold Limited | Households | 2012 |
| Hadley Consulting Engineers Ltd | Professional & scientific | 2020 |
| Hadley Court Residents Company Limited | Households | 1992 |
| Hadley Food and Wine Limited | Wholesale & retail | 2018 |
| Hadley Football Club Limited | Arts & recreation | 2022 |
| Hadley Gardens Management Company Limited | Other services | 2002 |
| Hadley Heights Management Limited | Households | 1979 |
| Hadley Homes Investments Ltd | Real estate | 2021 |
| Hadley House HB Ltd | Hospitality | 2018 |
| Hadley Kyte Surveyors Limited | Financial services | 2015 |
| Hadley Local Ltd | Wholesale & retail | 2024 |
| Hadley Organics Ltd | Manufacturing | 2025 |
| Hadley Properties Ltd | Real estate | 2019 |
| Hadley Property Management and Maintenance Limited | Construction | 2018 |
| Hadley Road (Freehold) Company Limited | Extraterritorial | 2007 |
| Hadley View Estates Limited | Real estate | 2010 |
| Hadley Wood Association | Other services | 2000 |
| Hadley Wood Golf Club Limited | Arts & recreation | 1976 |
| Hadley Wood Sports Trust | Arts & recreation | 2006 |
| Hadleybrook Limited | Information & communication | 2009 |
| Hadleyvale Court RTM Company Limited | Real estate | 2009 |
| Hadley’S Active Adventurers Ltd | Education | 2024 |
| Hadrian Court Freehold Limited | Households | 2000 |
| Hadrian Court Management Co. Limited | Households | 1986 |
| Hafizi Food and Bar Limited | Hospitality | 2025 |
| Haga Limited | Construction | 2020 |
| Hahn Properties Ltd | Real estate | 2000 |
| Haigh & Hill Consulting Limited | Professional & scientific | 2023 |
| Hailar Sandwich Ltd | Hospitality | 2025 |
| Hair by Keen Ltd | Other services | 2016 |
| Hair Discovery & Academy Ltd | Other services | 2014 |
| Hair Discovery Limited | Other services | 2011 |
| Hair Salon 101 Ltd | Other services | 2017 |
| Hair Solved London Ltd | Other services | 2009 |
| Hairco Hair & Beauty Ltd | Wholesale & retail | 2015 |
| Haker Media Limited | Information & communication | 2026 |
| Hakflow Ltd | Information & communication | 2022 |
| Hakks Barbers Limited | Other services | 2021 |
| Halcyon & Kingfisher Ltd | Households | 2020 |
| Half Moon London Ltd | Administrative & support | 2026 |
| Half Nelson Ltd | Administrative & support | 2015 |
| Hallowell Investments Limited | Professional & scientific | 1955 |
| Hallyj Jewellery Limited | Wholesale & retail | 2025 |
| Halo Presence Limited | Information & communication | 2026 |
| Halo Property Services Ltd | Real estate | 2021 |
| Halsa Mind Medical Limited | Health & social care | 2024 |
| Halstead Trading Limited | Real estate | 2020 |
| Hamdev Limited | Information & communication | 2013 |
| Hamilton Chase Estates Limited | Real estate | 2004 |
| Hamilton Fitness Limited | Arts & recreation | 2017 |
| Hamilton House (Whetstone) Management Ltd. | Households | 2001 |
| Hamilton Russell Harper Wood (Boston) Limited | Construction | 2022 |
| Hamilton Russell Harper Wood (WAR Rooms) Limited | Construction | 2022 |
| Hamiltons Surrey Limited | Construction | 2017 |