| Guardian Cleaning Management Limited | Administrative & support | 2011 |
| Gumdav Ltd | Professional & scientific | 2015 |
| H&D Services Ltd | Other services | 2021 |
| Hall Creative Services Ltd | Arts & recreation | 2024 |
| Hallmark Fabrics Ltd. | Wholesale & retail | 1994 |
| Hamfelds Home and Garden Limited | Wholesale & retail | 2011 |
| Hamlyn Smith Ltd | Real estate | 2021 |
| Hamlyn Smith MID Sussex Limited | Real estate | 2025 |
| Handbpropertyco Ltd | Real estate | 2026 |
| Hares Rustington Limited | Wholesale & retail | 2002 |
| Harmony Family Corporation (Private) Limited | Real estate | 2025 |
| Harrity Building & Construction Limited | Construction | 2012 |
| Hartland UK Limited | Arts & recreation | 2001 |
| Harts Holdings Limited | Hospitality | 2023 |
| Hayward & Green Limited | Extraterritorial | 2005 |
| Hayward and Green Aviation Limited | Transport & logistics | 1992 |
| Hayward and Green Aviation Trading Limited | Extraterritorial | 2002 |
| Hayward and Green Defence Ltd | Transport & logistics | 2002 |
| HCM Business Coaching Ltd | Administrative & support | 2025 |
| Head Home Ltd | Real estate | 2021 |
| Healy Callaghan Limited | Construction | 2012 |
| Heartbreaker Aesthetics Ltd | Other services | 2024 |
| Heartwood Creative Ltd | Arts & recreation | 2019 |
| Heat Sussex Ltd | Construction | 2021 |
| Henfield Artisan Market (HAM) Ltd | Wholesale & retail | 2024 |
| Henfield Community Partnership Limited | Other services | 2006 |
| Henfield Furnishings Limited | Real estate | 1972 |
| Henfield Handyman Ltd | Construction | 2025 |
| Henfield Haven Trading Company Limited | Hospitality | 2022 |
| Henfield Homes Limited | Construction | 2010 |
| Henfield Kebab Knights Limited | Hospitality | 2025 |
| HHC Developments Ltd. | Construction | 2011 |
| Highline Ltd | Wholesale & retail | 2015 |
| Holiday Home From Home UK Limited | Hospitality | 2024 |
| Holmbush Property Management Company Limited | Real estate | 1992 |
| Holt Services Limited | Transport & logistics | 1997 |
| Horse-Laundry.Com (Sussex) Limited | Other services | 2017 |
| Horsham Locksmiths Ltd | Administrative & support | 2022 |
| HOS Management Limited | Financial services | 2022 |
| Hospitality and Catering Group Ltd | Hospitality | 2013 |
| Hot Dog Productions Ltd | Information & communication | 2012 |
| House of Luxury Sussex Ltd | Other services | 2018 |
| House to GO2 Ltd | Real estate | 2025 |
| HR Resources Limited | Administrative & support | 2004 |
| Huntbell Limited | Real estate | 2009 |
| Hyatt Incorporated Ltd | Real estate | 2025 |
| Hyperion Realty Ltd | Construction | 2021 |
| HZL Homes Limited | Real estate | 2018 |
| I Move Haulage Ltd | Transport & logistics | 2019 |
| Iberica Ltd | Wholesale & retail | 2015 |
| Ifab Steel Ltd | Manufacturing | 2016 |
| Ifix Steel Solutions Ltd | Construction | 2016 |
| Imdc Holdings Limited | Extraterritorial | 2017 |
| Imperial Coffee Ltd | Hospitality | 2021 |
| Imperial Fortification Ltd | Other services | 2018 |
| Impressive PR Limited | Arts & recreation | 2014 |
| IN the Blue Limited | Extraterritorial | 2018 |
| Indian Treasures Ltd | Wholesale & retail | 2016 |
| Innerspace Office and Storage Limited | Real estate | 2010 |
| Innovo Medical Limited | Health & social care | 2010 |
| Inremo Ltd | Professional & scientific | 2025 |
| Inside Centre Limited | Professional & scientific | 2022 |
| Integrated Fire and Security Solutions Limited | Public administration | 2017 |
| Interesting Lizard Ltd | Information & communication | 2021 |
| Ivegotagreatidea- Ltd | Professional & scientific | 2012 |
| IWB Communications Ltd | Other services | 2023 |
| J B Kitesurfing Limited | Manufacturing | 2008 |
| J Group Construction Limited | Construction | 2026 |
| J M Services (South ) Ltd | Information & communication | 2018 |
| J Training Limited | Wholesale & retail | 2021 |
| J W & S a Walker (Property Management) Ltd | Real estate | 2008 |
| Jacksmowing Limited | Administrative & support | 2019 |
| James Tech Engineering Ltd | Professional & scientific | 2014 |
| Janik Properties Ltd | Real estate | 2023 |
| JB Electrical (West Sussex) Ltd | Construction | 2026 |
| JB Groundworks and Construction Ltd | Construction | 2023 |
| JC and Co Kitchen and Bathroom Specialist Ltd | Construction | 2026 |
| JDS Financial Services (Sussex) Ltd | Financial services | 2025 |
| Jeremy's Limited | Wholesale & retail | 2013 |
| Jeremy's Two Limited | Wholesale & retail | 2017 |
| JF Building & Maintenance Ltd | Construction | 2020 |
| JJS Park Homes Limited | Construction | 2024 |
| JJS Realty 1 Limited | Real estate | 2025 |
| JJS Realty 2 Limited | Real estate | 2025 |
| JK Industries Ltd | Real estate | 2025 |
| JKB Groundworks and Construction Ltd | Construction | 2017 |
| JL Scaffolding (Sussex) Ltd | Construction | 2024 |
| JLA Consulting Services Limited | Information & communication | 2004 |
| JM BOZ Holdings Ltd | Real estate | 2025 |
| Jmed Properties Ltd | Real estate | 2022 |
| Jmed Supplies Ltd | Other services | 2014 |
| Johns and Purdew Ltd | Construction | 2016 |
| JP Bryant Rentals Ltd | Real estate | 2018 |
| JTE Consultants Ltd | Professional & scientific | 2023 |
| K S & E R Berrett LLP | | 2021 |
| K. Willis Consulting Limited | Professional & scientific | 2010 |
| Kamalo Heel Ltd | Financial services | 2025 |
| Karen Trace Associates Limited | Professional & scientific | 2009 |
| KB Fitness & Nutrition Limited | Arts & recreation | 2011 |
| KCH Design Limited | Real estate | 2015 |