| H Foreman Ltd | Construction | 2023 |
| H J Stoner Limited | Wholesale & retail | 2014 |
| H S Recruitment Limited | Administrative & support | 2003 |
| Hacketts Financial Services Ltd | Financial services | 2023 |
| Hacketts Property Investments Ltd | Real estate | 2023 |
| Haddon HR Ltd | Professional & scientific | 2025 |
| Haine & SON Limited | Other services | 1984 |
| Halo Veneering Limited | Manufacturing | 2010 |
| Hamilton Coaching Ltd | Administrative & support | 2026 |
| Hammonds Ridge Management (NO. 1) Limited | Real estate | 1989 |
| Hanner Construction Sussex Ltd | Construction | 2025 |
| Haoli LAI Limited | Real estate | 2022 |
| Haoyun LAI Enterprise Ltd | Hospitality | 2020 |
| Haraka Baraka Ltd | Administrative & support | 2024 |
| Harley Street Shoulder Surgeon Ltd | Health & social care | 2025 |
| Harramelotti PUB Company Ltd | Hospitality | 2009 |
| Harrington Benn Ltd | Administrative & support | 2012 |
| Harris HR Consultancy Limited | Administrative & support | 2018 |
| Harts Hall Place Management Limited | Households | 2021 |
| Harvey Maria Limited | Construction | 1995 |
| Harvita Services Ltd | Administrative & support | 2018 |
| Harwoods Consulting Ltd | Information & communication | 2025 |
| Hassocks Community Organisation | Public administration | 2010 |
| Hawkins Enterprise Limited | Construction | 2011 |
| Hawkshead Productions Ltd | Information & communication | 2024 |
| Haydul Property Company Limited | Construction | 1972 |
| Haywards Heath Town Team CIC | Administrative & support | 2013 |
| HCD Engineering Limited | Professional & scientific | 1973 |
| HCD Holdings Limited | Financial services | 2015 |
| Hdhod.Com Ltd | Education | 2020 |
| Healthstyle Ltd | Health & social care | 2024 |
| Heath Bathrooms Limited | Wholesale & retail | 2000 |
| Heath Pilates Ltd | Health & social care | 2024 |
| Heath Veterinary Clinic Ltd | Professional & scientific | 2010 |
| Heath Wood (Felbridge) Management Company Limited | Households | 2015 |
| Heatherview Management Limited | Households | 2008 |
| Hedzon Consulting Limited | Information & communication | 2015 |
| HEL Estates Limited | Real estate | 2025 |
| Helicom Ltd | Construction | 2017 |
| Henjack Consulting Limited | Professional & scientific | 2025 |
| Henry & Henry Build Ltd | Construction | 2025 |
| Henry Fraser Financial Ltd | Financial services | 2024 |
| Hepburn Consulting Ltd | Professional & scientific | 2025 |
| HER Socially Linked Network Ltd | Information & communication | 2024 |
| Heritage & Sons Limited | Other services | 1979 |
| Hexad Property Limited | Construction | 2013 |
| HG Aviation Ltd | Transport & logistics | 2024 |
| Higher END Properties Limited | Real estate | 2023 |
| Highfields (Ansty) Management Company Limited | Households | 2020 |
| Highsted Trading Limited | Construction | 2015 |
| Hillgay Ltd | Health & social care | 2015 |
| Hillian Trading Ltd | Wholesale & retail | 2022 |
| Hillians Bricks Ltd | Wholesale & retail | 2024 |
| Hillians Trading Ltd | Hospitality | 2023 |
| Hiphipballoonsco Ltd | Arts & recreation | 2024 |
| Hive (Hassocks) Limited | Other services | 2023 |
| Hiykon Consulting Engineers Limited | Professional & scientific | 2017 |
| Hiykon Group Limited | Arts & recreation | 2018 |
| Hiykon Limited | Arts & recreation | 1962 |
| Hiykon Pro Audio Limited | Arts & recreation | 2016 |
| Hiykon Productions Limited | Arts & recreation | 2017 |
| Hkbt Enterprises Ltd | Wholesale & retail | 2023 |
| Hoads of Sussex Limited | Wholesale & retail | 2023 |
| Hoathly South Street Management Limited | Households | 2008 |
| Hobgoblin Music Limited | Extraterritorial | 2008 |
| Hockley Surfacing Limited | Construction | 2005 |
| Hoffice Pods Ltd. | Manufacturing | 2021 |
| Hofmann Accountants Ltd | Professional & scientific | 2021 |
| Hofmann Investments Ltd | Real estate | 2024 |
| Holding Kindness Ltd | Education | 2025 |
| Holfernoak Property Management Limited | Households | 1998 |
| Holistically Ginger Ltd | Extraterritorial | 2015 |
| Holly Wren Photography Limited | Arts & recreation | 2012 |
| Hollywood Property Management Company Limited | Households | 2007 |
| Home Adaptation UK Ltd. | Construction | 2006 |
| Home Buyers UK Limited | Real estate | 2004 |
| Home Harmony Lettings Ltd | Real estate | 2025 |
| Home Physio OPS Limited | Professional & scientific | 2024 |
| HOME121 Ltd | Administrative & support | 2022 |
| Homefit Tyres Ltd | Manufacturing | 2025 |
| Homeland International Limited | Extraterritorial | 2015 |
| Homesmart Drainage Ltd | Water & waste | 2024 |
| Honvale Limited | Real estate | 1973 |
| Horsham Coffee Roaster Limited | Hospitality | 2015 |
| Hose Connecting Solutions Ltd | Manufacturing | 2017 |
| Hossini Group Ltd | Wholesale & retail | 2025 |
| Hotter Shoes Limited | Wholesale & retail | 2023 |
| House of Lockyer Ltd | Real estate | 2025 |
| House of Tweed Online Ltd | Wholesale & retail | 2020 |
| House Proud Finish Limited | Administrative & support | 2019 |
| Houz Projects Limited | Professional & scientific | 2023 |
| Howland Investments Ltd | Real estate | 2024 |
| HP Taxis Haywards Heath Ltd | Transport & logistics | 2025 |
| Hp-Ent Limited | Health & social care | 2017 |
| HS ZEN Smart Ltd | Construction | 2025 |
| HSB Barbers Limited | Other services | 2024 |
| Hsenergy Group Ltd | Construction | 2015 |
| Hsev Ltd | Wholesale & retail | 2024 |
| HTF Event Services Limited | Arts & recreation | 2024 |
| Human Optimisation Ltd | Other services | 2023 |