| Furzefield Farm Ltd | Hospitality | 2021 |
| Futra Associates Limited | Professional & scientific | 2012 |
| Fuzzmedia Limited | Professional & scientific | 2019 |
| G Standing Roofing Ltd | Construction | 2018 |
| G&Vl Ltd | Construction | 2020 |
| G.Dauncey Ltd | Professional & scientific | 2019 |
| Gaia Clinic Ltd | Health & social care | 2026 |
| Garagefarm.Net Ltd | Information & communication | 2010 |
| Garden Room Contractors Ltd | Construction | 2026 |
| GAS Recovery & Recycle Limited | Manufacturing | 2008 |
| Gaston Gate Garage Limited | Wholesale & retail | 1991 |
| Gatewick Farm Limited | Transport & logistics | 2007 |
| Gatewick Gardens Ltd | Arts & recreation | 2026 |
| Gelert Design Limited | Professional & scientific | 2025 |
| GEN2PLANK Limited | Manufacturing | 2021 |
| Geoff Greenfield Limited | Construction | 1999 |
| Geoff Moseley Consultancy Limited | Construction | 2017 |
| Georgie & Henners Limited | Wholesale & retail | 2021 |
| Geraldine Reilly Consultancy Limited | Real estate | 2013 |
| Ghost Create & Build Ltd | Manufacturing | 2015 |
| GM Plumbing & Heating Services Ltd | Construction | 2021 |
| GM Steel Erectors Limited | Construction | 2017 |
| Goddard Engineering Limited | Manufacturing | 2007 |
| Godfrey Oliver Windows Ltd | Construction | 2016 |
| Golden Ratio Ltd | Wholesale & retail | 2003 |
| Golding Barn Estates Limited | Real estate | 1993 |
| Golding Barn Raceway Limited | Arts & recreation | 2004 |
| Gorringes Brook Management Company Limited | Households | 1999 |
| Gracias Plumbing Solutions Ltd | Construction | 2019 |
| Grant Digital Ltd | Professional & scientific | 2025 |
| Grant Distribution Ltd | Wholesale & retail | 2025 |
| Granville (Hove) Limited | Households | 2004 |
| Green Farm Restoration Limited | Other services | 1990 |
| Green Rewards Limited | Administrative & support | 2011 |
| Greenacres (Horsham 4 ) RTM Company Limited | Households | 2011 |
| Greenacres (Horsham 4) Management Company Limited | Households | 1991 |
| Guardx Limited | Professional & scientific | 2025 |
| H Khushbu Ltd | Hospitality | 2022 |
| H&D Mortgages Ltd | Financial services | 2016 |
| H.J. Burt Land Limited | Real estate | 2024 |
| Hambro and Miller Limited | Wholesale & retail | 2013 |
| Hamill & Head Ltd | Construction | 2025 |
| Hamilton Graham Sales & Lettings Limited | Real estate | 2025 |
| Hardings Coaches Limited | Transport & logistics | 2003 |
| Harps Oak House Limited | Households | 2017 |
| Hartley Thomas Ltd | Information & communication | 2010 |
| Hatiassets Ltd | Hospitality | 2024 |
| HEADROOM4HEALTH Limited | Health & social care | 2018 |
| Heat MAT Limited | Wholesale & retail | 2003 |
| Heat-Com (UK) Limited | Wholesale & retail | 2002 |
| Heath Residential Estates Limited | Real estate | 2002 |
| Heatmat Group Holdings Limited | Manufacturing | 2022 |
| Heatmat Holdings Limited | Manufacturing | 2018 |
| Helena Heal Financial Services Ltd | Financial services | 2007 |
| Hemmingways 2 Limited | Other services | 2023 |
| Henfield and District Angling Properties Limited | Financial services | 2023 |
| Herringborne Limited | Information & communication | 2022 |
| Hesketh Group Limited | Manufacturing | 2024 |
| Hesketh Solutions Limited | Construction | 2020 |
| Heyworth Place Management Company Limited | Households | 1994 |
| Highseas Authors Limited | Arts & recreation | 1978 |
| Highview Scaffolding Limited | Construction | 2019 |
| Hobart Paving Company Limited | Extraterritorial | 1972 |
| Hollywood Fine Art Limited | Wholesale & retail | 1982 |
| House of Norris Limited | Wholesale & retail | 2024 |
| HS7 Ltd | Hospitality | 2018 |
| Huddlestone Farmers Limited | Agriculture & fishing | 1987 |
| Huntley Investments Ltd | Real estate | 2020 |
| Hurst Court(Horsham)Residents' Association Limited | Households | 1962 |
| Hurstfield Residents' Association Limited | Households | 1976 |
| Hyperion Partners Ltd | Administrative & support | 2023 |
| I.H.S. Trading Company Ltd | Professional & scientific | 2000 |
| Icebreaker Ventures LLP | | 2005 |
| Iceology Limited | Wholesale & retail | 2020 |
| Identiparts Limited | Wholesale & retail | 2003 |
| Imax Visual Ltd | Information & communication | 2009 |
| Imperial Contracting Limited | Construction | 2001 |
| IN OUR Hands CIC | Education | 2023 |
| Incrementum Growth Solutions Limited | Administrative & support | 2013 |
| Inflatable Boat Fishing Ltd | Wholesale & retail | 2018 |
| Insight Consulting Services Limited | Professional & scientific | 2024 |
| Insight Executive Group Limited | Professional & scientific | 2014 |
| Insight Executive Limited | Extraterritorial | 2016 |
| Insight Executive Solutions Limited | Administrative & support | 2022 |
| Integral Home Improvements Ltd | Construction | 2023 |
| International Headache Society | Administrative & support | 1994 |
| IP Source Ltd | Administrative & support | 2024 |
| IQ App Solutions Ltd | Information & communication | 2026 |
| Iscos Conferences Ltd | Administrative & support | 2015 |
| Isha Annual Scientific Meeting 2025 Limited | Administrative & support | 2024 |
| Isha HIP Preservation Limited | Administrative & support | 2021 |
| J and F Catering Services Limited | Hospitality | 2018 |
| J F Heagerty Limited | Construction | 1996 |
| James Laretive Prestige Autos Ltd | Wholesale & retail | 2020 |
| James Luckin Limited | Administrative & support | 2014 |
| Jamie's Gardens Limited | Agriculture & fishing | 2013 |
| Japalanteh Development Limited | Manufacturing | 2013 |
| Jb&Co Barbers Limited | Other services | 2021 |
| JDJ Design & Consulting Ltd | Information & communication | 2024 |
| Jericho Management Company Limited | Real estate | 2010 |