| Green Squid Ltd | Information & communication | 2018 |
| Greyhound Way Freehold Limited | Administrative & support | 2010 |
| Greystoke Plant Hire Limited | Administrative & support | 2024 |
| Griffin Williams Ltd | Construction | 2026 |
| Grosvenor FEE Protection Limited | Financial services | 2014 |
| Grounded Systems Ltd | Information & communication | 2008 |
| GT Electrical Sussex Ltd | Construction | 2024 |
| Guineapig Limited | Professional & scientific | 2016 |
| Gujral Capital Ltd | Real estate | 2024 |
| Gujral Holdings Investment Ltd | Real estate | 2020 |
| Gunn Building Services Limited | Construction | 2005 |
| Gunns Investments Limited | Real estate | 2017 |
| Guru Estates Ltd | Real estate | 2024 |
| Guru Financial Ltd | Other services | 2022 |
| Guru Wills and Estate Planning Limited | Administrative & support | 2024 |
| GZC Limited | Administrative & support | 2013 |
| H V Lynch Ltd | Professional & scientific | 2013 |
| H.C.A. Entertainment Limited | Arts & recreation | 1996 |
| Hair by Bethan Ltd | Other services | 2021 |
| Hair Solutions Storrington Ltd | Other services | 2013 |
| Hanbury Park (1939) Ltd | Arts & recreation | 2023 |
| Hanchi Consultancy Ltd | Professional & scientific | 2019 |
| Hand in Glove Ltd | Information & communication | 2013 |
| Handel Rating Consultancy Limited | Professional & scientific | 2015 |
| Hanna Bandara Medical Ltd | Health & social care | 2019 |
| Hansel House Management Company Limited | Households | 1982 |
| Hare & Field Ltd | Wholesale & retail | 2026 |
| Harlem Eubank Ltd | Health & social care | 2022 |
| Harnessing Communications Limited | Information & communication | 2024 |
| Harnessing Energy Limited | Construction | 2022 |
| Hashir International Specialist Clinics & Research Institute for Misophonia, Tinnitus and Hyperacusis Ltd | Health & social care | 2013 |
| Hashtag 13 Ltd | Construction | 2024 |
| Hassocks Barbers Ltd | Other services | 2025 |
| Hassocks Football Club Limited | Arts & recreation | 2006 |
| Hassocks Golf Club Limited | Extraterritorial | 1997 |
| Hassocks Lodge Residents Association Limited | Real estate | 2002 |
| Hassocks Pet Centre Ltd | Wholesale & retail | 2013 |
| Hasti Enterprises Ltd | Hospitality | 2016 |
| Hastwood Consultants Ltd | Professional & scientific | 2017 |
| Hatley D.P.F Limited | Professional & scientific | 2000 |
| Hatley D.P.F NO.1 Limited | Professional & scientific | 2000 |
| Hatley Developments Limited | Construction | 2002 |
| Hatley Homes Limited | Construction | 1995 |
| Hatley Restaurants Limited | Construction | 2001 |
| Hawk Engineering Limited | Construction | 2015 |
| HC Porsche Ltd | Wholesale & retail | 2024 |
| Health Cheque Limited | Financial services | 1998 |
| Hearn Design Limited | Manufacturing | 2014 |
| Heartsquid Films Limited | Professional & scientific | 2022 |
| Heathfield Dental Care Limited | Health & social care | 2007 |
| Hedgecraft Ltd | Manufacturing | 2019 |
| Heed Consulting Limited | Professional & scientific | 2025 |
| Helix Maintenance Limited | Construction | 2019 |
| Hello Consulting Limited | Professional & scientific | 2023 |
| Helping Hand Trading Ltd | Administrative & support | 2016 |
| Henfield Village Cars Limited | Transport & logistics | 2010 |
| Henry Cole Associates Limited | Information & communication | 1996 |
| Heritage Property Leaders Ltd | Real estate | 2022 |
| Hermiyas Ltd | Hospitality | 2024 |
| HI5 Group Ltd | Information & communication | 2023 |
| Hickstead Farming Limited | Agriculture & fishing | 2000 |
| Hickstead Limited | Arts & recreation | 1960 |
| High Street Coworking Limited | Other services | 2023 |
| High Street Wellness Ltd | Arts & recreation | 2023 |
| Highfield Construction Services Ltd | Construction | 2013 |
| Highline Heating Ltd | Construction | 2025 |
| Hills Architectural Design Ltd | Construction | 2020 |
| Hilton Taylor Ltd | Real estate | 2014 |
| Hitchcock Wynne Productions Limited | Information & communication | 2015 |
| HNB Recruitment Ltd | Administrative & support | 2018 |
| HNB Training Limited | Education | 2012 |
| Holley Holdings Ltd | Professional & scientific | 2025 |
| Hollingdean Properties Ltd | Real estate | 2023 |
| Hollprop Limited | Real estate | 2020 |
| Holm Developments Ltd | Real estate | 2026 |
| Homecall Carpets (Sussex) Ltd | Wholesale & retail | 2007 |
| Homely Touch Ltd | Wholesale & retail | 2013 |
| Honey Real Estate Limited | Professional & scientific | 2025 |
| Honeypot Hove Ltd | Hospitality | 2018 |
| HOP TUB Brewing Ltd | Hospitality | 2022 |
| Hopcroft Associates Ltd | Professional & scientific | 2013 |
| Hot Property Estates Ltd | Real estate | 2024 |
| Hot Property Rentals Ltd | Hospitality | 2024 |
| HS Cafe Ltd | Hospitality | 2023 |
| Huish Wine Limited | Manufacturing | 2026 |
| Humanity at Heart Trading Company Limited | Wholesale & retail | 1995 |
| Hurst Brewery Ltd | Manufacturing | 2017 |
| Hurst Facilities Limited | Transport & logistics | 1977 |
| Hurst Hand Car Wash Ltd | Administrative & support | 2024 |
| Hurst International Limited | Education | 2015 |
| Hurst PIT Stop Garage Ltd | Wholesale & retail | 2025 |
| Hurst PIT Stop Ltd | Administrative & support | 2024 |
| Hurst Transport Limited | Transport & logistics | 2012 |
| Hurstpierpoint College Limited | Education | 1999 |
| Hyperludic Ltd | Information & communication | 2025 |
| I Smudged IT Ltd | Wholesale & retail | 2025 |
| I Z Pharma Limited | Health & social care | 2005 |
| I9 Tax Ltd | Professional & scientific | 2022 |
| Icehaven Limited | Real estate | 1997 |
| Icon AMC Ltd | Administrative & support | 2024 |