| Govcats Ltd | Information & communication | 2013 |
| Gower Construction Limited | Construction | 2009 |
| GP Practice Signposting & Care Navigation Toolkit Ltd | Information & communication | 2022 |
| GP Practice Training Ltd | Education | 2023 |
| GPP Maintenance Limited | Administrative & support | 2015 |
| GPR Machinery Ltd | Manufacturing | 2015 |
| GRA Digital Ltd | Information & communication | 2018 |
| Graham Cottingham Limited | Construction | 2009 |
| Gramm Barrier Systems Limited | Construction | 2006 |
| Granary Storage Limited | Administrative & support | 2023 |
| Grand Landscapes Limited | Administrative & support | 2021 |
| Grant Property Services Limited | Real estate | 2011 |
| Grant's Garage (Brighton) Limited | Wholesale & retail | 2004 |
| Granted Homes Limited | Real estate | 2006 |
| Grass Support UK Limited | Wholesale & retail | 2023 |
| Grassline Limited | Administrative & support | 2024 |
| Grassmate Limited | Construction | 2019 |
| Gray Chambers Ltd | Households | 2020 |
| Grays Fine Art Limited | Wholesale & retail | 2013 |
| Green Construction & Maintenance Ltd | Construction | 2014 |
| Green DAN Ltd | Professional & scientific | 2012 |
| Green Earth Plan CIC | Education | 2020 |
| Green Orbit International Limited | Administrative & support | 2024 |
| Green Stables Consulting Limited | Professional & scientific | 2024 |
| Green Windows Ltd. | Administrative & support | 2019 |
| Greener Plumbing Ltd | Construction | 2019 |
| Gregory and SON Construction Ltd | Construction | 2026 |
| Gresham Corporate Holdings Limited | Professional & scientific | 2013 |
| Gresham Securities Limited | Professional & scientific | 2013 |
| Greystone Development (South East) Limited | Construction | 2019 |
| Grisham Limited | Health & social care | 2013 |
| Ground UP Coffee Limited | Hospitality | 2024 |
| Growth Partnership Ltd | Professional & scientific | 2024 |
| GRU Languages Ltd | Education | 2021 |
| GU Events Limited | Hospitality | 2026 |
| Guernsey Chocolate Limited | Manufacturing | 2025 |
| Guildford Market Street Ltd | Other services | 2024 |
| Guirao Design Ltd | Professional & scientific | 2019 |
| GUN Hill Studios Limited | Professional & scientific | 2014 |
| GW Environmental Limited | Administrative & support | 2012 |
| Gym Box Fitness Ltd | Arts & recreation | 2024 |
| H R Carpentry Limited | Construction | 2014 |
| H&S Innovations Ltd | Wholesale & retail | 2021 |
| HAB (Eastbourne) Limited | Financial services | 2012 |
| Habitual Home Ltd | Wholesale & retail | 2020 |
| Hackett Retail Limited | Wholesale & retail | 2025 |
| Hackhurst Farm LLP | | 2021 |
| Hadrian Services LLP | | 2019 |
| Haduma Ltd | Information & communication | 2013 |
| Haffenden's Limited | Administrative & support | 2002 |
| Hailsham & East Sussex Adhd Support CIC | Education | 2026 |
| Hailsham Auto Electricians Ltd | Wholesale & retail | 2024 |
| Hailsham Autobody Repairs Limited | Wholesale & retail | 2002 |
| Hailsham Boxing Club C.I.C. | Education | 2024 |
| Hailsham CMC Limited | Professional & scientific | 2004 |
| Hailsham Community College Academy Trust | Education | 2012 |
| Hailsham FM Ltd | Information & communication | 2015 |
| Hailsham Forward CIC | Administrative & support | 2018 |
| Hailsham Funeral Service Limited | Professional & scientific | 1993 |
| Hailsham Roadway Construction Co. Limited | Construction | 1966 |
| Hailsham Technology Ltd | Other services | 2017 |
| Hailsham Town Council CIC | Public administration | 2018 |
| Hailsham Youth Service CIC | Education | 2024 |
| Hairy Dog Brewery Ltd | Manufacturing | 2017 |
| Hajela Medical Limited | Health & social care | 2018 |
| Halil & Nile Ltd | Hospitality | 2025 |
| Hallmark Glazed Extensions Ltd | Construction | 2019 |
| Hallworth Associates Limited | Professional & scientific | 2015 |
| Hammerston Limited | Real estate | 1987 |
| Hammerton (UK) Limited | Administrative & support | 2010 |
| Hampden Radiology LLP | | 2022 |
| Hampshire Service Centre Limited | Wholesale & retail | 2011 |
| Hancock Estates Limited | Professional & scientific | 2010 |
| Handswork Limited | Administrative & support | 2002 |
| Hankham Motor Works Limited | Wholesale & retail | 2012 |
| Hanlie Limited | Information & communication | 2017 |
| Hansom Homes Limited | Real estate | 2001 |
| Happy Bear Ltd | Information & communication | 2015 |
| Harding Bond Limited | Administrative & support | 2015 |
| Hardwick House Limited | Construction | 2024 |
| Hardy Paving Limited | Administrative & support | 2012 |
| Harebeating Crescent Maintenance Limited | Households | 1965 |
| Harman Sussex Developments Limited | Construction | 2024 |
| Harman Sussex Holdings Ltd | Construction | 2024 |
| Harman Sussex Limited | Construction | 2024 |
| Harmers HAY (Hailsham) Limited | Households | 1964 |
| Harmony Hearing Solutions Ltd | Health & social care | 2020 |
| Harrington Property Investments Ltd | Real estate | 2013 |
| Harris Ashwood Properties Limited | Real estate | 2020 |
| Harrison Carpentry & Construction Limited | Manufacturing | 2021 |
| Hart Autos Ltd | Wholesale & retail | 2017 |
| Hart Coleman Ltd | Real estate | 2012 |
| Hartfield Group Limited | Extraterritorial | 2016 |
| Harvey Heritage Solutions Limited | Manufacturing | 2024 |
| Hastings Kickboxing Academy Ltd | Arts & recreation | 2020 |
| Hastings Kombat Academy Ltd | Arts & recreation | 2024 |
| Hatch Sports Limited | Arts & recreation | 2023 |
| Havealuke Ltd | Professional & scientific | 2026 |
| Hawkeye Advisory Limited | Professional & scientific | 2025 |
| Hayes Barbers Lounge Limited | Other services | 2025 |