| Hamshaw Partners Ltd | Professional & scientific | 2021 |
| Hanako Limited | Information & communication | 2015 |
| Hand Drawn Limited | Arts & recreation | 2006 |
| Handcross Butchers Ltd | Wholesale & retail | 2013 |
| Handcross Engineering Limited | | 1964 |
| Handcross Park Commercial Services Limited | Wholesale & retail | 2016 |
| Hanlye Estates Limited | Real estate | 2002 |
| Hannah LN Holdings Limited | Health & social care | 2015 |
| Happy Dayz Dogs Ltd | Agriculture & fishing | 2020 |
| Happy Nails & Spa Limited | Other services | 2024 |
| Harbeth Audio Ltd. | Manufacturing | 1999 |
| Harlands Educational Trust | Education | 2014 |
| Harman Group Estates Ltd | Real estate | 2024 |
| Harman Paul Ltd. | Other services | 2016 |
| Harman Properties Group Limited | Real estate | 2023 |
| Haroonallahdad Limited | Wholesale & retail | 2026 |
| Harper Fairweather Ltd | Professional & scientific | 2025 |
| Harperlea Properties Limited | Other services | 2014 |
| Harrabin Consultancy Limited | Professional & scientific | 2010 |
| Harrington Wines LLP | | 2021 |
| Harry Batten Bakery Limited | Hospitality | 2020 |
| Harry Cauty Ltd | Information & communication | 2024 |
| Hart Country Stores Limited | Wholesale & retail | 2020 |
| Hart Equity Release Limited | Financial services | 2020 |
| Hartello Ltd | Administrative & support | 2024 |
| Hartford Bridge Management Company Limited | Households | 2006 |
| Harvey Capital Holdings Ltd | Financial services | 2025 |
| Harvey Sands (Sussex) Limited | Professional & scientific | 2010 |
| Harvey Sands LLP | | 2010 |
| Harveys Car Centre Limited | Wholesale & retail | 2010 |
| Harveys Property Ltd | Real estate | 2022 |
| Harwell Finance Group Limited | Financial services | 2019 |
| Harwell Protection Group Limited | Financial services | 2020 |
| Hashtag Clean Ltd | Administrative & support | 2014 |
| Hassocks Holdings Limited | Real estate | 2016 |
| Hatcat Limited | Information & communication | 2023 |
| Hatch & Hatch Ltd | Professional & scientific | 2025 |
| Hatch Farm Land Limited | Real estate | 2017 |
| Hatch Farm Trading Ltd | Administrative & support | 2017 |
| Haus at NO. 6 Limited | Wholesale & retail | 2005 |
| Havenhurst Investments Limited | Real estate | 2015 |
| Havenhurst Management Consultants Limited | Professional & scientific | 2017 |
| Hawkings Alexander (Tanyard Farm) Limited | Construction | 2025 |
| Hawkings Alexander Limited | Construction | 2016 |
| Hawkins Security Systems Limited | Administrative & support | 2019 |
| Haworth Homes Limited | Real estate | 2024 |
| Hawthorne Court Estate (Epsom) Limited | Other services | 1979 |
| HAY Mobile Ltd | Other services | 2016 |
| Hayden Lea-White Building Contractor Limited | Construction | 2015 |
| Haywards Heath Autospa Ltd | Administrative & support | 2025 |
| Haywards Heath Business Association Limited | Other services | 2019 |
| Haywards Heath Cabs Ltd | Transport & logistics | 2024 |
| Haywards Heath Landscapes Limited | Administrative & support | 2020 |
| Haywards Heath Panthers C.I.C. | Education | 2025 |
| Haywards Heath Plumbing and Heating Ltd | Construction | 2019 |
| Haywards Heath Rugby Football Club Limited | Arts & recreation | 2009 |
| Haywards Heath Sushi Ltd | Hospitality | 2017 |
| Haywards Heath Taxis &Van Ltd | Transport & logistics | 2025 |
| Haywards Heath Taxis Services Ltd | Transport & logistics | 2024 |
| Haywards Heath Tennis Club Ltd | Arts & recreation | 2022 |
| Haywards Heath Town CIC | Construction | 2013 |
| Haywards Heath Town Youth Football Club | Arts & recreation | 2019 |
| Hazalalp Ltd | Hospitality | 2020 |
| Hazel & Moss Ltd | Hospitality | 2026 |
| Hazeldene Project Management Limited | Administrative & support | 2008 |
| HCI Contracts Limited | Manufacturing | 2005 |
| Hcpl Limited | Professional & scientific | 2013 |
| Hdits Ltd | Information & communication | 2020 |
| HDP Environmental Consulting Limited | Professional & scientific | 2020 |
| Health Consultants Ltd | Health & social care | 2009 |
| Health Ergonomics Consultancy Limited | Health & social care | 2009 |
| Heart and Soul Limited | Other services | 1993 |
| Heartventure Limited | Other services | 2014 |
| Heartwood Forest School Limited | Education | 2013 |
| Heath Square (Amenities) Limited | Real estate | 1987 |
| Heathland Hotels Limited | Hospitality | 1998 |
| Heckingood Ltd | Professional & scientific | 2020 |
| Heels Sussex LLP | | 2013 |
| Heilu Limited | Real estate | 2019 |
| Helen Bradburn Ltd | Professional & scientific | 2013 |
| Helen Tuddenham Consulting Ltd | Professional & scientific | 2020 |
| Helenscourt Consulting Limited | Professional & scientific | 2023 |
| Hello Genius Limited | Information & communication | 2014 |
| Hello Sweeptech LLP | | 2008 |
| Hells Angels (London) Limited | Other services | 1992 |
| Helme & Hallett Limited | Construction | 1964 |
| Help for Hearing | Other services | 2018 |
| Helter Skelter Records Limited | Wholesale & retail | 2008 |
| Henfield Flooring Limited | Wholesale & retail | 2013 |
| Henry C. Collison and Sons Limited | Wholesale & retail | 1969 |
| Henry Hurst Limited | Professional & scientific | 2006 |
| Henry Mews (Haywards Heath) Management Company Ltd | Real estate | 2013 |
| Henshin Group Limited | Information & communication | 2018 |
| Henton Design and Build Limited | Construction | 2025 |
| Henton Ransom Limited | Professional & scientific | 2017 |
| Heritage Testing Limited | Professional & scientific | 2005 |
| Hero Corp Limited | Administrative & support | 2014 |
| Herridge Consulting Limited | Professional & scientific | 2018 |
| Herringstream Limited | Administrative & support | 2019 |
| Herstmonceaux Management Company Limited | Households | 2026 |