| Grounded Coffee (ST Margarets) Limited | Hospitality | 2026 |
| Grounded Coffee Co. Limited | Hospitality | 2011 |
| Grover Jewellery & Accessories Limited | Manufacturing | 2020 |
| Grow BAG Capital Ltd | Financial services | 2013 |
| Grow Investment Advice Ltd | Financial services | 2023 |
| Grow Investments Humber Limited | Real estate | 2020 |
| Grow Investments Limited | Real estate | 2014 |
| Grow Property Alder Limited | Real estate | 2020 |
| Grow Property Birch Limited | Real estate | 2021 |
| Grow Property Oak Limited | Real estate | 2018 |
| Grow Property Willow Limited | Real estate | 2021 |
| Grow the Good Limited | Administrative & support | 2024 |
| Gsamj Limited | Professional & scientific | 2018 |
| Gsgg Limited | Wholesale & retail | 2019 |
| GSR Build Limited | Construction | 2003 |
| GTM Resourcing Limited | Administrative & support | 2025 |
| GTM Services Group Limited | Administrative & support | 2025 |
| GTM Strategy Partners Limited | Administrative & support | 2025 |
| Guellal RA Consulting Limited | Professional & scientific | 2012 |
| Guided Roots Ltd | Health & social care | 2026 |
| Gulshan Landmarks Ltd | Real estate | 2024 |
| Gunby Productions Ltd | Information & communication | 2011 |
| Gurkha Durbar Limited | Professional & scientific | 2005 |
| Gurkha Inn Ltd | Hospitality | 2025 |
| Gurkha Manpower Ltd | Administrative & support | 2022 |
| Gursar Limited | Information & communication | 2025 |
| GUS Kimber Limited | Information & communication | 2011 |
| GW Connect Ltd | Professional & scientific | 2015 |
| GYS Estate Limited | Real estate | 2026 |
| H & H Accounting Limited | Professional & scientific | 2016 |
| H a D Software Limited | Information & communication | 2002 |
| H Concept Design Ltd | Professional & scientific | 2016 |
| H Dawson Consultancy Ltd | Professional & scientific | 2020 |
| H Ductin Limited | Construction | 2006 |
| H L S Leisure Limited | Hospitality | 2005 |
| H M Facilities Management Ltd | Real estate | 2023 |
| H S Property (London) Ltd | Real estate | 2023 |
| H Trendz Limited | Wholesale & retail | 2017 |
| H&H Business Development Ltd | Other services | 2017 |
| H.B. Partners (Engineers) Limited | | 1957 |
| H.R. Consultancy Richmond Ltd | Administrative & support | 2019 |
| H2N Wealth Management Limited | Financial services | 2019 |
| H2SNOW Limited | Hospitality | 2015 |
| Habibe Designs Limited | Manufacturing | 2003 |
| Habitats & Heritage | Education | 2010 |
| Habitats & Heritage Social Enterprise Ltd Ltd | Information & communication | 2015 |
| Hackett Songs Limited | Administrative & support | 2008 |
| HAI LUA Limited | Hospitality | 2021 |
| Hair (Twickenham) Limited | Other services | 2014 |
| Haka Barber Ltd | Other services | 2024 |
| Halcolux Fleet Ltd | Transport & logistics | 2026 |
| Halcolux Limited | Transport & logistics | 2023 |
| Hallas & Co West Ltd | Professional & scientific | 2019 |
| Hallas & Co. Limited | Professional & scientific | 2011 |
| Hallas Commercial Ltd | Professional & scientific | 2021 |
| Hallas Design Consultants Ltd | Professional & scientific | 2021 |
| Hallas Design LLP | | 2013 |
| Hallas Property Investments Ltd | Real estate | 2017 |
| Halo Investment Holdings Ltd | Financial services | 2024 |
| Halo Investment Holdings Properties Limited | Real estate | 2014 |
| Halo Investments 1 Ltd | Financial services | 2024 |
| Halo Investments 2 Ltd | Financial services | 2024 |
| Halo Investments 3 Ltd | Financial services | 2024 |
| Halos Music Ltd | Information & communication | 2021 |
| Hamill Logistics Limited | Transport & logistics | 2022 |
| Hamilton Design Build Ltd | Construction | 2021 |
| Hamilton Weston Wallpapers Limited | Wholesale & retail | 1986 |
| Hampton Chase Limited | Professional & scientific | 2019 |
| Hampton Gents Barbers Ltd | Other services | 2024 |
| Hanabi Films Limited | Information & communication | 2015 |
| Hanban Consulting Limited | Construction | 2014 |
| Hanban Property Limited | Households | 2023 |
| Handy Sherpa Construction Limited | Construction | 2026 |
| Handyease Ltd | Information & communication | 2025 |
| Hanh Hoang Estates Ltd | Real estate | 2026 |
| Hannah Weall Marketing Ltd | Professional & scientific | 2024 |
| Hanoi Media Limited | Other services | 2021 |
| Happ Ltd | Information & communication | 2024 |
| Happy Death Ltd. | Information & communication | 2013 |
| Happy Go Mummy Ltd | Wholesale & retail | 2025 |
| Happy Shop London Ltd | Wholesale & retail | 2025 |
| Harbour House Management Company Limited | Hospitality | 1998 |
| Hardy-Smith Holdings Ltd | Real estate | 2015 |
| Hare's Furniture Limited | Manufacturing | 2018 |
| Harehouse Limited | Construction | 1999 |
| Harihar Enterprise Ltd | Wholesale & retail | 2023 |
| Harimaz Limited | Professional & scientific | 1997 |
| Harlequin Campus Limited | Arts & recreation | 2017 |
| Harlequin Estates (Twickenham) Limited | Real estate | 1971 |
| Harlequin FC Holdings Limited | Financial services | 2013 |
| Harlequin Finance PLC | Financial services | 2015 |
| Harlequin Football Club Limited | Arts & recreation | 1996 |
| Harlequin Womens Football Club Limited | Arts & recreation | 2023 |
| Harleys Homes Ltd | Construction | 2025 |
| Harmer Enterprises Limited | Education | 2020 |
| Harmer Trade Consultancy Ltd | Other services | 2025 |
| Harmonia Marketing & PR Ltd | Professional & scientific | 2014 |
| Harp Consultancy Services Limited | Professional & scientific | 2016 |
| Harrisons Investments Limited | Professional & scientific | 2022 |
| Harrisons Window Cleaning Company Ltd | Administrative & support | 2019 |