| Guard-Scene-Medical Ltd | Health & social care | 2025 |
| Guinea 1775 Limited | Wholesale & retail | 2015 |
| Gulliver Search Limited | Professional & scientific | 2025 |
| Guruji Blessings Always Properties Ltd | Real estate | 2026 |
| Gyan-Netra International Charity Ltd | Health & social care | 2010 |
| Gymnastics World Ltd | Arts & recreation | 2023 |
| Gymtastic Ltd | Arts & recreation | 2023 |
| H & K Building Services Ltd | Construction | 2015 |
| H and M Building Services Ltd | Construction | 2021 |
| H B Films Ltd | Information & communication | 2016 |
| H Power International Limited | Professional & scientific | 1989 |
| H S Sembhi Builders Limited | Construction | 2018 |
| H&H Power Sales Ltd | Wholesale & retail | 2020 |
| H&S Auto Repair & Recovery Limited | Wholesale & retail | 2018 |
| H.P.R.A. Ltd. | Households | 1989 |
| H2G LAB Ltd | Information & communication | 2016 |
| H2H Retail Solutions Limited | Wholesale & retail | 2020 |
| HAB Cars Ltd | Wholesale & retail | 2024 |
| Hadfield Place Management Company Limited | Households | 2021 |
| Hadi Properties Ltd | Real estate | 2023 |
| Haha Marketing Limited | Professional & scientific | 2013 |
| Haileybury (Freehold) Limited | Households | 2016 |
| HAK Cuisine Ltd | Hospitality | 2020 |
| Halstone Limited | Hospitality | 2003 |
| Halvorsen Invest Ltd | Construction | 2026 |
| HAM Island Residents Association Limited | Households | 1998 |
| Hamlet Properties (UK) Limited | Real estate | 2000 |
| Haniesta Ltd | Wholesale & retail | 2025 |
| Hannon Partners Limited | Professional & scientific | 2020 |
| Hanover Park (Ascot) Freehold Limited | Households | 2024 |
| Hanover Park (Ascot) Management Company Limited | Real estate | 2005 |
| Happie Chahal Trading Ltd | Wholesale & retail | 2026 |
| Happy Blossoms of Berkshire Limited | Hospitality | 2018 |
| Happy Diggs Ltd | Information & communication | 2023 |
| Happy Otters London Limited | Health & social care | 2024 |
| HAQ Removals Ltd | Transport & logistics | 2026 |
| Hard CUT Post Production Ltd | Information & communication | 2011 |
| Hardriding House Limited | Health & social care | 2003 |
| Hardy Wealth Management Limited | Financial services | 2025 |
| Harefield Place Management Company Limited | Other services | 2018 |
| Harefield Road Management Company (NO. 2) Limited | Households | 1986 |
| Harfateh Housing Ltd | Real estate | 2023 |
| Hariselvan Services Limited | Other services | 2013 |
| Harnam Food & Wine Ltd | Wholesale & retail | 2021 |
| Harpar Estates Ltd. | Real estate | 2017 |
| Harrington & FOX Estates Ltd | Real estate | 2017 |
| Harrison Bond Properties Limited | Real estate | 2020 |
| Harscar II Limited | Wholesale & retail | 2018 |
| Harscar Limited | Information & communication | 2016 |
| Hartley Copse Residents Company Limited | Households | 1992 |
| Harvest Community Ventures CIC | Education | 2025 |
| Harvey Duckers Consulting Limited | Professional & scientific | 2014 |
| Harvey Heals Wellbeing Consultancy Limited | Education | 2022 |
| Harvey Square Limited | Information & communication | 2009 |
| HAT & Ice Finance Limited | Financial services | 2011 |
| Hatchet Lane Farm (Ascot) Management Co Ltd | Households | 2022 |
| Hatton Court 7-12 Ltd. | Households | 2013 |
| Havana House Ltd | Other services | 2023 |
| Haven Green Developments Ltd | Real estate | 2025 |
| Hawb Development Limited | Extraterritorial | 2009 |
| Hawthorn Hill Services Limited | Construction | 1976 |
| Haydin Estate Ltd | Real estate | 2024 |
| Haydock Health Limited | Professional & scientific | 2023 |
| Hayle Mill Management Company Limited | Households | 2007 |
| Hazgo Limited | Water & waste | 2014 |
| Hcas Holdings Limited | Administrative & support | 2018 |
| Health and Well-Being Consulting Ltd | Health & social care | 2007 |
| Health Values Ltd | Professional & scientific | 2020 |
| Healthcare Line Limited | Health & social care | 2022 |
| Hear Line Ltd | Health & social care | 2011 |
| Hearne Court (Amersham) Management Company Limited | Households | 2013 |
| Heat Care (South) Limited | Manufacturing | 2005 |
| Heathlands Point Residents Management Company Limited | Households | 2019 |
| Heathmoor (Shrewsbury) Limited | Real estate | 2014 |
| Heathrow Boxing Club Limited | Arts & recreation | 2011 |
| Heathrow Concrete Limited | Other services | 2016 |
| Heathrow Developers Limited | Real estate | 2025 |
| Heathrow VET Services Limited | Professional & scientific | 2013 |
| Heatsense Services Limited | Construction | 2022 |
| Hedley Clark Limited | Professional & scientific | 2005 |
| Heidi (Station) Limited | Hospitality | 2021 |
| Heidi (Windsor) Limited | Hospitality | 2011 |
| Heidi Bakery Limited | Hospitality | 2016 |
| Heidi Studio Limited | Manufacturing | 2021 |
| Helios Court Freehold Company Limited | Households | 2017 |
| Helios Court Residents Management Company Limited | Households | 2014 |
| Helios Marketing Solutions Limited | Hospitality | 2010 |
| Hellshire Limited | Professional & scientific | 2017 |
| Helptran Limited | Professional & scientific | 2010 |
| Helygen Consulting Ltd | Professional & scientific | 2020 |
| Hemeray Designs Ltd | Information & communication | 2025 |
| Henna Properties Ltd | Real estate | 2021 |
| Heritage Gaskets Ltd | Wholesale & retail | 2014 |
| Hermes Publications Ltd | Manufacturing | 2012 |
| Heron Lodge (Windsor) Management Company Limited | Households | 1972 |
| Heronsbrook Apartments Limited | Real estate | 2002 |
| Heronsbrook Rent Charge Management Limited | Real estate | 2002 |
| Herstel Ltd | Administrative & support | 2011 |
| Hervines Court Management Company Limited | Real estate | 1989 |
| Hervines Road Amersham Management Limited | Households | 2003 |