| Greenrock Projects Limited | Construction | 2017 |
| Greens Group Holdings Limited | Wholesale & retail | 1990 |
| Greystones Court (Crowborough) Limited | Real estate | 2016 |
| Griffin Builders and Contractors Limited | Construction | 2014 |
| Grosvenor Training Holdings Limited | Professional & scientific | 1999 |
| Grosvenor Training Services Limited | Education | 1993 |
| Groundtruth Consulting Limited | Information & communication | 2005 |
| Grove House Media Limited | Information & communication | 2025 |
| Growing Earth Consultancy Limited | Professional & scientific | 2014 |
| Growth by Design Limited | Professional & scientific | 2016 |
| Guilded Markets Ltd | Professional & scientific | 2025 |
| Guzel Asya Ltd | Other services | 2012 |
| GVI Experiences Limited | Administrative & support | 2025 |
| H T Partnership LLP | | 2006 |
| H&H BTN Ltd | Hospitality | 2024 |
| H-Temen Invest Ltd. | Financial services | 2016 |
| H.M.T. Plastics Limited | Manufacturing | 1976 |
| H.T.P. Limited | Extraterritorial | 1991 |
| Hack Engineering Ltd | Wholesale & retail | 2017 |
| Hadlow Hideaways Limited | Transport & logistics | 2019 |
| Halfpoint Ltd | Real estate | 2012 |
| Halftrade Ltd | Real estate | 2012 |
| Halley Diamond System Ltd | Extraterritorial | 2015 |
| Hallmark Engraving & Signs Ltd | Manufacturing | 1977 |
| Hamble Property Management Ltd | Households | 2022 |
| Hamilton Removals Limited | Transport & logistics | 2025 |
| Hamilton Storage & Removals Limited | Transport & logistics | 2025 |
| Hammerwood Investments Limited | Extraterritorial | 1972 |
| Harlands Grange Management Limited | Real estate | 2000 |
| Harlequin Electrical & Property Specialists Ltd | Construction | 2021 |
| Harling Foundries Ltd | Manufacturing | 2022 |
| Harmonic Resonance Solutions Limited | Other services | 2016 |
| Harmony at Home Limited | Administrative & support | 2010 |
| Harmony Homes (Sussex) Limited | Construction | 2001 |
| Harper Payne LLP | | 2017 |
| Harris Black Hartanah Ltd | Real estate | 2026 |
| Haven Paraplanning Ltd | Financial services | 2019 |
| Hayley Beeson School of Dance Ltd | Arts & recreation | 2011 |
| Headford Digital Limited | Administrative & support | 2016 |
| Health Partners Group Limited | Administrative & support | 2016 |
| Healthtech Consulting Ltd | Professional & scientific | 2014 |
| Hear & More Limited | Health & social care | 2024 |
| Heathdyne Properties Limited | Construction | 1995 |
| Heathrow Newstead Limited | Professional & scientific | 2024 |
| Hedges & Swan Building Services Ltd | Construction | 2024 |
| Hellowp Ltd | Information & communication | 2019 |
| Hemera Energy Limited | Energy | 2016 |
| Hempstead Park Management Limited | Households | 1990 |
| Hepzon Ltd | Wholesale & retail | 2012 |
| Herbaferm Ltd | Manufacturing | 2021 |
| Herbowski Limited | Wholesale & retail | 2017 |
| Hgsb Ltd | Wholesale & retail | 2011 |
| HHS Sussex Ltd | Hospitality | 2026 |
| Hidden Path Holdings Ltd | Professional & scientific | 2025 |
| Highfielder Ltd | Professional & scientific | 2026 |
| Highland Grange Limited | Professional & scientific | 1988 |
| Hillrise (Heathfield) Management Limited | Real estate | 1998 |
| HIM Invest Ltd | Information & communication | 2016 |
| Hitc Limited | Wholesale & retail | 2024 |
| Hitme Global Ltd | Wholesale & retail | 2021 |
| Hmsi Ltd | Administrative & support | 2016 |
| Hockney Creative Media Limited | Administrative & support | 2010 |
| Hofthouse Foods Ltd | Hospitality | 2014 |
| Holland & Johnston Ltd | Construction | 2019 |
| Holland & Johnston Properties Ltd | Real estate | 2023 |
| Holley Brothers Ltd | Transport & logistics | 2020 |
| Holley Limited | Manufacturing | 2001 |
| Holman Estates Limited | Administrative & support | 2019 |
| Holy Cross Management Company Limited | Professional & scientific | 2011 |
| Home Credit Finance Ltd | Financial services | 2012 |
| Homemead Management Company Limited | Real estate | 1997 |
| Homesōko Ltd | Wholesale & retail | 2025 |
| Honours and Awards Ltd | Manufacturing | 2022 |
| HOP Poles BTN Ltd | Hospitality | 2026 |
| Horizon Performance Cars Ltd | Wholesale & retail | 2019 |
| Horsedream UK Limited | Extraterritorial | 2004 |
| Horseshoe Bay Limited | Real estate | 2014 |
| Horsted Estates Limited | Financial services | 2013 |
| Hortus Collective Ltd | Professional & scientific | 2019 |
| Hortus Make Ltd | Manufacturing | 2025 |
| House Call VET Ltd | Professional & scientific | 2020 |
| Howse Hunter Ltd | Administrative & support | 2025 |
| Howseman Housing Ltd | Real estate | 2025 |
| Hudson Universal UK LLP | | 2017 |
| Hunter Finance (UK) Limited | Financial services | 2010 |
| Hunter Lettings Ltd | Real estate | 2008 |
| Hunter Medical Limited | Health & social care | 2020 |
| Hunter Sporting (UK) Limited | Construction | 2019 |
| Hunter UV Ltd | Manufacturing | 2020 |
| Huntrade Ltd | Wholesale & retail | 2016 |
| Hurst Farms Limited | Agriculture & fishing | 2016 |
| Hvac IT Services Ltd | Information & communication | 2024 |
| Hydrocare Leisure Limited | Other services | 2019 |
| I Office Ltd | Information & communication | 2007 |
| I I Gruber Ltd | Administrative & support | 2013 |
| IB Lettings Ltd | Real estate | 2025 |
| ICM Services Group Limited | Construction | 2026 |
| ICU Escape Ltd | Education | 2024 |
| Ideal Chimney Sweep Limited | Administrative & support | 2022 |
| IGB Brickwork Limited | Construction | 2018 |