| Glam Bar Newhaven Limited | Other services | 2017 |
| Glenthorne House (Eastbourne) Limited | Households | 2003 |
| Global Shading Solutions Limited | Construction | 2018 |
| Glopack JSM Solutions Limited | Wholesale & retail | 2021 |
| Glopack Solutions Limited | Other services | 2018 |
| Glopek Limited | Financial services | 2018 |
| Goddards Investments Ltd | Financial services | 2016 |
| Golden Green Academy Ltd | Manufacturing | 2025 |
| Good Cycle Ltd | Transport & logistics | 2022 |
| Gotsheim Property LLP | | 2020 |
| Green Mclain Turner Limited | Information & communication | 2021 |
| Greenacre Recycling Limited | Water & waste | 2001 |
| Grosvenor Court Seaford Limited | Hospitality | 2014 |
| Ground FLO Ltd | Construction | 2025 |
| Group 333 Limited | Construction | 2026 |
| GSX Transport Ltd | Transport & logistics | 2020 |
| Hakuna Matata International Ltd | Wholesale & retail | 2024 |
| Halben Ltd | Information & communication | 2025 |
| Harper & Bell Estate Agents Ltd | Real estate | 2023 |
| Harpers Road RTM Company Limited | Households | 2017 |
| Harris Wholesale Ltd | Wholesale & retail | 2019 |
| Harrod-Edwards Sales and Marketing Consultancy Ltd | Professional & scientific | 2024 |
| Hart Essence Ltd | Arts & recreation | 2022 |
| Harwood King Printmakers Limited | Professional & scientific | 2015 |
| Harwood Motor Services Ltd | Wholesale & retail | 2024 |
| Hassocks and District Angling Society Limited | Arts & recreation | 2011 |
| Haven Home Loans Limited | Financial services | 2007 |
| Haven House Management Company Ltd | Households | 2002 |
| Haven Mews Cattery Limited | Hospitality | 2011 |
| Haven Superfry Fish Chip Ltd | Hospitality | 2024 |
| Heartwood Systems Ltd | Manufacturing | 2014 |
| Heaven Nails Newhaven Limited | Other services | 2022 |
| Helix Retail Ltd | Information & communication | 2015 |
| Hello CNC Ltd | Other services | 2020 |
| Hello Flamingo Ltd | Manufacturing | 2014 |
| Hello Plinths Ltd | Other services | 2020 |
| Hestiafireplace Limited | Construction | 2023 |
| High Beach House Residents Company Limited | Other services | 1992 |
| Highbury Farm Limited | Agriculture & fishing | 2014 |
| Highcroft Mews Brighton (Residents) Limited | Households | 1999 |
| Hillcrest Community Partnership | Education | 1998 |
| Hippocat Ltd | Professional & scientific | 2023 |
| HJM Media Limited | Information & communication | 2019 |
| HKN Foods Ltd | Wholesale & retail | 2025 |
| HM Bookkeeping & Payroll Services Ltd | Professional & scientific | 2013 |
| Holts Capital Holdings Ltd | Financial services | 2026 |
| Home Heatwear Ltd | Wholesale & retail | 2026 |
| Homecare | | 1998 |
| Honours List IQ Ltd | Administrative & support | 2020 |
| Hoodies for Habitats Ltd. | Manufacturing | 2025 |
| Howards Facilities Management Limited | Administrative & support | 2011 |
| Howards Fire Protection Limited | Public administration | 2022 |
| Howards Property Services Ltd | Real estate | 2025 |
| Hoyle Plumbing & Heating Services Ltd | Construction | 2015 |
| HR Developments (Sussex) Ltd | Construction | 2025 |
| HSL Ltd | Construction | 2005 |
| Hunters LNH Ltd | Administrative & support | 2009 |
| Hylab Dispensers Limited | Manufacturing | 2023 |
| I Like a Sweetie Limited | Wholesale & retail | 2014 |
| ICF Innovations Ltd | Construction | 2022 |
| IDK Logistics Ltd. | Transport & logistics | 2016 |
| Improvements UN Limited | Real estate | 2018 |
| Inesa UK Limited | Manufacturing | 2015 |
| Ingram Cars Limited | Extraterritorial | 2016 |
| Innovative Offshore Developments Ltd | Professional & scientific | 2012 |
| Insight Paraplanning Ltd | Financial services | 2020 |
| Inspirational Apparel Ltd | Extraterritorial | 2016 |
| Interface 2 Limited | Manufacturing | 1996 |
| Intermodal Solutions Limited | Professional & scientific | 2018 |
| Intrepid Counselling Ltd | Health & social care | 2024 |
| IP Nominees Limited | Administrative & support | 2018 |
| Iris Brooker Limited | Information & communication | 2026 |
| J Emery Properties Ltd | Real estate | 2018 |
| J M Brown Ltd | Administrative & support | 2019 |
| J Samuel White & Co Limited | Extraterritorial | 2010 |
| J Stevens Plumbing and Heating Limited | Construction | 2019 |
| J. R. H. Electrical (U.K.) Ltd | Construction | 2013 |
| Janiak and SON Consulting Ltd | Professional & scientific | 2020 |
| Jasfic Limited | Construction | 2016 |
| Jasons Barber Shop Limited | Other services | 2009 |
| Jaybee Engineering Company(Brighton)Limited | Manufacturing | 1964 |
| Jemibless Limited | Wholesale & retail | 2026 |
| JHC Construction Ltd | Construction | 2025 |
| JHJ Property Investments Ltd | Real estate | 2019 |
| JKC Move Management Ltd | Transport & logistics | 2006 |
| JM Risk Solutions Ltd | Financial services | 2015 |
| JMB Solutions & Investments Ltd | Real estate | 2019 |
| JMJ Storage Solutions Ltd | Transport & logistics | 2019 |
| JNC Recruitment Limited | Administrative & support | 2011 |
| Jobs Without Borders Ltd | Administrative & support | 2023 |
| Jolly Good Homes Ltd | Construction | 2023 |
| Julian Wild Limited | Arts & recreation | 2018 |
| JWF Testing Ltd | Information & communication | 2025 |
| JXP Consultancy Ltd | Professional & scientific | 2014 |
| K Dolinek Ltd | Construction | 2015 |
| K&H Plumbing & Heating Limited | Construction | 2021 |
| K24 Telecom Ltd | Information & communication | 2018 |
| Kaamoc Foods Limited | Wholesale & retail | 2025 |
| Kande UK Ltd | Wholesale & retail | 2020 |
| KB Builders (Sussex) Limited | Construction | 2008 |