| Italian Bistro Bexhill Limited | Hospitality | 2026 |
| Italian Restaurant Bexhill Limited | Hospitality | 2025 |
| Itec Controls Ltd | Information & communication | 2015 |
| Itech Specialist Ltd. | Administrative & support | 2015 |
| ITS East Sussex Limited | Real estate | 2025 |
| It’S NOT What YOU Think Ltd | Professional & scientific | 2021 |
| Iulia Gabriela Limited | Health & social care | 2019 |
| Ivan and Sarah Mather Developments Limited | Construction | 2016 |
| Ivawil Ltd | Wholesale & retail | 2026 |
| Ivebury W10 Limited | Real estate | 2013 |
| Iver Adam Limited | Other services | 2024 |
| Iverna Limited | Real estate | 2014 |
| IVO Trading Limited | Financial services | 2009 |
| IVY House Clinic Limited | Health & social care | 2025 |
| IVY House Day Centre Limited | Health & social care | 2010 |
| IVY Stationery Limited | Wholesale & retail | 1985 |
| Iwood Investments Ltd | Professional & scientific | 2021 |
| Ixworth Limited | Professional & scientific | 2013 |
| Izon Associates Ltd | Other services | 2019 |
| J & J Invest Limited | Health & social care | 2016 |
| J & S Pharma Support Limited | Professional & scientific | 2024 |
| J and B Projects Limited | Extraterritorial | 2013 |
| J and H Logistics Limited | Transport & logistics | 2024 |
| J B Electrolysis Ltd | Other services | 2021 |
| J D W C Limited | Information & communication | 1998 |
| J E Davidson Ltd | Professional & scientific | 2025 |
| J Foster Holdings Limited | Real estate | 2024 |
| J Group Bespoke Glass Limited | Construction | 2011 |
| J Group Glazing Limited | Construction | 2011 |
| J Group Shopfitting Services Limited | Construction | 2011 |
| J J Cleaning Limited | Administrative & support | 2024 |
| J K Finnis Ltd | Hospitality | 2012 |
| J K M Enterprises Limited | Financial services | 2018 |
| J K Smiles Limited | Health & social care | 2021 |
| J K Wilson & Sons Limited | Manufacturing | 2021 |
| J Kirby Electrical Ltd | Construction | 2011 |
| J Leigh Consulting Ltd | Information & communication | 2025 |
| J Louis Limited | Construction | 2015 |
| J M & Sons Ltd | Administrative & support | 2017 |
| J M P Consulting Ltd | Information & communication | 2026 |
| J P Windshields Limited | Wholesale & retail | 2002 |
| J R Wholesale (Sussex) Limited | Wholesale & retail | 2016 |
| J R Wooler Bespoke Services Ltd | Construction | 2016 |
| J Rose Equine Physiotherapy Limited | Other services | 2022 |
| J S Management Solutions Limited | Financial services | 2018 |
| J Sheila Limited | Health & social care | 2022 |
| J Sowden Consultancy Limited | Professional & scientific | 2025 |
| J T Plumbing Services Limited | Construction | 2023 |
| J W Tiling Limited | Construction | 2015 |
| J&J Investments Limited | Health & social care | 2026 |
| J&L Hope Holdings Ltd | Financial services | 2022 |
| J&M Environmental Ltd | Professional & scientific | 2015 |
| J. & E. Cruttenden Limited | Construction | 1964 |
| J. a Carpentry and Joinery Limited | Construction | 2024 |
| J. a. G. Scaffold Rigging Limited | Construction | 1998 |
| J.K Distributor Limited | Hospitality | 2022 |
| J.R Plastering and Rendering Limited | Construction | 2019 |
| J2 Construction and Building Ltd | Construction | 2022 |
| J2 Design Ltd | Administrative & support | 2018 |
| Jaanvi & Company Limited | Real estate | 2021 |
| Jaaw Hospitality Limited | Hospitality | 2024 |
| Jacey Withers Ltd | Wholesale & retail | 2015 |
| Jack London Productions Limited | Information & communication | 2009 |
| Jackpot Films and Music Limited | Arts & recreation | 2001 |
| Jackpot IT Services Limited | Information & communication | 2009 |
| Jackpot Management Consultancy Limited | Information & communication | 2020 |
| Jackson and Spark Limited | Professional & scientific | 2017 |
| Jackson Flooring Ltd | Construction | 2009 |
| Jackson Public Speaking Ltd | Other services | 2023 |
| Jacob Drive Limited | Real estate | 2024 |
| JAD Codes Ltd | Information & communication | 2022 |
| Jaguar House Property Limited | Real estate | 2016 |
| Jagwant Singh Limited | Health & social care | 2021 |
| JAI Amba Mata 1 Limited | Wholesale & retail | 2020 |
| JAI Amba Mata 29 Limited | Wholesale & retail | 2023 |
| JAI SAI Kamal Care Ltd | Health & social care | 2025 |
| JAI Scudder Limited | Construction | 2013 |
| Jaideep Care Limited | Health & social care | 2022 |
| Jakk Country Furniture Designs Limited | Manufacturing | 2010 |
| JAL Clarke Hair Ltd | Other services | 2024 |
| Jalp Healthcare Limited | Health & social care | 2021 |
| JAM Corporation Limited | Financial services | 2017 |
| JAM Education Ltd | Education | 2023 |
| Jamedical (South East) Limited | Wholesale & retail | 2010 |
| James Bourne Wealth Management Limited | Financial services | 2017 |
| James Dodd Associates Ltd | Administrative & support | 2025 |
| James Hamilton Investments Ltd | Real estate | 2025 |
| James Thompson Design Limited | Professional & scientific | 2024 |
| James Toland Limited | Professional & scientific | 2024 |
| Jamie Ballan Associates Limited | Administrative & support | 2014 |
| Jamm Trading Limited | Financial services | 2025 |
| Jamuk Properties Ltd | Households | 2026 |
| JAN Rombouts Interiors Ltd | Wholesale & retail | 2018 |
| Janard Property Consultants LLP | | 2002 |
| Jane Delaney Properties Limited | Real estate | 1963 |
| Jane Milton Ltd | Professional & scientific | 2012 |
| Janet Wewe Ltd | Health & social care | 2024 |
| Jarrah Care Group Limited | Health & social care | 2025 |
| Jarretts Motors Limited | Wholesale & retail | 1991 |
| Jarvis Drylining and Plastering Limited | Construction | 2021 |