| Isle of Wight Studio Glass Ltd | Manufacturing | 2013 |
| Isle of Wight Vacations Limited | Administrative & support | 2017 |
| Isle of Wight Venues LLP | | 2017 |
| Isle of Wight Visionplus Limited | Wholesale & retail | 1994 |
| Isle of Wight Youth Trust | Health & social care | 2001 |
| Islington Close (Newport) Management Limited | Households | 2006 |
| Islington Close (Phase 2) Management Limited | Households | 2009 |
| Islwyn Lettings and Holdings Ltd | Real estate | 2026 |
| ISM (IOW) Limited | Manufacturing | 2007 |
| ISM Solutions UK Ltd | Professional & scientific | 2018 |
| Ismael and Chowdhury Ltd | Hospitality | 2025 |
| Ismet & Boran Ltd | Extraterritorial | 2024 |
| Isorropia Foundation Community Interest Company | Health & social care | 2018 |
| Isotropic Ltd | Professional & scientific | 2006 |
| Iszar Limited | Real estate | 2023 |
| It's the Joint Ltd | Hospitality | 2024 |
| It's Your People Ltd | Professional & scientific | 2025 |
| Ital Food Ltd | Hospitality | 2024 |
| Itconsec Ltd | Information & communication | 2019 |
| ITE Solutions Ltd | Information & communication | 2008 |
| Itemdeal Limited | | 1983 |
| ITG Marine Ltd | Information & communication | 2024 |
| Itgrp Ltd | Information & communication | 2014 |
| ITS Tools IOW Limited | Manufacturing | 2013 |
| Itso Solutions Limited | Information & communication | 2020 |
| Iuas Education Ltd | Education | 2022 |
| IUI Limited | Hospitality | 2023 |
| IUN Ltd | Hospitality | 2026 |
| IV Platinum Spirits Ltd | Wholesale & retail | 2026 |
| Iverley Construction Contracts Limited | Construction | 2017 |
| Ivor Aston Limited | Financial services | 2022 |
| Ivor Cook Ltd | Construction | 2003 |
| Ivor Harvey Ltd | Real estate | 2019 |
| Ivory White Bridal Alterations Limited | Manufacturing | 2024 |
| IVY Bank Management Company Limited | Households | 1989 |
| IVY Court Cottages Limited | Hospitality | 2003 |
| IW Espresso Limited | Wholesale & retail | 2026 |
| IW Observer Limited | Information & communication | 2019 |
| IWA24 Ltd | Wholesale & retail | 2024 |
| Iwight Homes Limited | Real estate | 2019 |
| Iwithacircle Ltd | Information & communication | 2018 |
| Izone Solutions Limited | Information & communication | 2024 |
| Izuka Limited | Health & social care | 2014 |
| Izzu Mart Limited | Manufacturing | 2025 |
| J & B Sewing Machine Company Limited | Manufacturing | 1961 |
| J & D Stores Ltd | Wholesale & retail | 2025 |
| J & E Morris LLP | | 2011 |
| J & H Flooring Limited | Construction | 2007 |
| J & J Morris Limited | Households | 2017 |
| J & L Thompson Limited | Construction | 2006 |
| J & P Harris Limited | Real estate | 2005 |
| J & V Awatar Ltd | Real estate | 2022 |
| J a Dennis Limited | Wholesale & retail | 2005 |
| J and J Vehicle Body Limited | Wholesale & retail | 2025 |
| J Anstey Construction Limited | Construction | 2025 |
| J Batch Wind Services Ltd | Manufacturing | 2024 |
| J Benjamin Property Ltd | Real estate | 2019 |
| J C Developments (UK) Ltd | Information & communication | 2013 |
| J C S Construction Services Limited | Wholesale & retail | 2008 |
| J D G Building and Scaffolding Ltd | Construction | 2018 |
| J Derrick Paving Limited | Construction | 2026 |
| J Doherty Plant Hire Ltd | Administrative & support | 2020 |
| J F Dallyn Limited | Agriculture & fishing | 2012 |
| J G Two Limited | Arts & recreation | 2015 |
| J G Wind Services Ltd | Manufacturing | 2024 |
| J Griffiths Services Limited | Administrative & support | 2024 |
| J Haste Ltd | Information & communication | 2023 |
| J Heard Roofing and Building Ltd | Construction | 2025 |
| J K Jones Property Maintenance Ltd | Construction | 2026 |
| J L Bradford Ltd | Manufacturing | 2024 |
| J M Bubb & SON LLP | | 2022 |
| J M Building & Restoration Ltd | Construction | 2010 |
| J M C Golf Limited | Wholesale & retail | 2020 |
| J M Developments IOW Limited | Construction | 2026 |
| J Maintenance Services Limited | Professional & scientific | 2018 |
| J N M (NPT) Ltd | Hospitality | 2019 |
| J N Textile UK Ltd | Wholesale & retail | 2015 |
| J Nessa Ltd | Households | 2019 |
| J P Brazier Design & Build Limited | Construction | 2002 |
| J Plant Limited | Administrative & support | 2016 |
| J R Associates (Wales) Limited | Administrative & support | 2013 |
| J R Buckett and Sons Limited | Construction | 2000 |
| J R Electrical SW Limited | Construction | 2022 |
| J R Morgan Dental Limited | Health & social care | 2019 |
| J Rogers Property Developments Ltd | Construction | 2023 |
| J T Quiney Transport Ltd | Transport & logistics | 2021 |
| J V Graphics Limited | Manufacturing | 2011 |
| J Wray Consulting Limited | Professional & scientific | 2023 |
| J YIN Medical Services Limited | Health & social care | 2019 |
| J Z Transit Ltd | Transport & logistics | 2022 |
| J&B Continental Food Supplier Ltd | Extraterritorial | 2018 |
| J&B Contracting Services Ltd | Construction | 2022 |
| J&B Marine Services Ltd | Agriculture & fishing | 2025 |
| J&B Porth Store Limited | Wholesale & retail | 2022 |
| J&B Utility Services Limited | Construction | 2025 |
| J&C Roofing & Building Limited | Construction | 2025 |
| J&E Lloyd Holdings Limited | Financial services | 2018 |
| J&F Property Group Ltd | Real estate | 2025 |
| J&G Joinery and Building Maintenance Limited | Construction | 2011 |
| J&J Industries Ltd | Arts & recreation | 2019 |