| Iconsol Limited | Information & communication | 2012 |
| Ideal Life Show Ltd | Administrative & support | 2016 |
| Ielts Connect Ltd | Education | 2022 |
| Iftb Digital Ltd | Information & communication | 2026 |
| Iftb Ltd | Professional & scientific | 2025 |
| IGA Properties Limited | Real estate | 2020 |
| IIM Media Ltd | Administrative & support | 2024 |
| Illingworth Estates Ltd | Real estate | 2020 |
| Imagine Studio Group Ltd | Financial services | 2024 |
| Immi Consulting Ltd | Wholesale & retail | 2024 |
| Implant Sage Ltd | Health & social care | 2018 |
| Impulse Therapy Limited | Other services | 2025 |
| Incubated Ltd | Wholesale & retail | 2019 |
| Indelible Productions UK Limited | Information & communication | 2006 |
| Independent Living Specialists Limited | Financial services | 2012 |
| Indigo (Hassocks) Limited | Wholesale & retail | 2010 |
| Indigo Bear Limited | Other services | 2007 |
| Infield Management Services Limited | Professional & scientific | 2003 |
| Infuzed Ltd | Wholesale & retail | 2023 |
| Ingenium Automotive Design Ltd | Manufacturing | 2024 |
| Ins-Uk Limited | Construction | 2019 |
| Insert Name Limited | Professional & scientific | 2017 |
| Insight Construction Group Ltd | Construction | 2019 |
| Inspiration Media Ltd | Information & communication | 2025 |
| Instafin Limited | Professional & scientific | 2014 |
| Integrated Living Solutions Limited | Real estate | 2025 |
| Intercollective Limited | Financial services | 2024 |
| Interpsych Ltd | Health & social care | 2025 |
| Into Investments Limited | Real estate | 2024 |
| Investor Reach Limited | Professional & scientific | 2024 |
| Isabello's Pre-School Ltd | Education | 2018 |
| Isle of Wight Radio Holdings Limited | Information & communication | 2009 |
| Isle of Wight Radio Limited | Information & communication | 1988 |
| It's a Doggy Dog World Ltd | Professional & scientific | 2019 |
| Itronic Limited | Professional & scientific | 2002 |
| Ivnc Limited | Real estate | 2026 |
| J & J Integrated Ltd | Construction | 2026 |
| J & LH Consulting Limited | Professional & scientific | 2017 |
| J & M Brighton Consulting Ltd | Information & communication | 2019 |
| J C Charity Card and Gift Service Limited | | 1978 |
| J Heed Limited | Real estate | 2014 |
| J LEE Trees Limited | Administrative & support | 2009 |
| J Tindall Construction Ltd | Construction | 2020 |
| J&R Refurbishments Ltd | Construction | 2019 |
| J.F.Poynter Limited | Wholesale & retail | 1938 |
| J.Peskett Electrical Ltd | Construction | 2022 |
| Jack & Jill Inn (Clayton) Limited | Hospitality | 2014 |
| Jack & Jill Payments Ltd | Administrative & support | 2020 |
| Jack Taggart & Company Ltd | Administrative & support | 2018 |
| Jackdaw Creation Limited | Manufacturing | 2025 |
| James Cheung Plumbing and Heating Limited | Construction | 2013 |
| Jashy Limited | Financial services | 2020 |
| Javad Properties Limited | Real estate | 2006 |
| JAY & Wren Ltd | Professional & scientific | 2026 |
| JAY Cover Ltd | Professional & scientific | 2022 |
| JC Japan Ltd | Arts & recreation | 2023 |
| JC Resin Bound Surfacing Limited | Construction | 2024 |
| JCL Property Group Ltd | Real estate | 2019 |
| JD Winch Electrical Ltd | Construction | 2022 |
| JED Berry Barber Limited | Other services | 2022 |
| Jetline Stores UK Ltd | Wholesale & retail | 2021 |
| JG PR Limited | Professional & scientific | 2008 |
| Jimco Limited | Real estate | 2004 |
| Jiya Software Ltd | Information & communication | 2024 |
| Jiyaan Ltd | Administrative & support | 2012 |
| JLH Properties Ltd | Real estate | 2019 |
| JMR Electrical Limited | Construction | 2024 |
| JMS Brands Ltd | Wholesale & retail | 2025 |
| JMT Property Management Ltd | Real estate | 2018 |
| JO Grows Ltd | Professional & scientific | 2025 |
| JOB Share Professionals Ltd | Extraterritorial | 2014 |
| Jocelyn Crouch Consulting Ltd | Professional & scientific | 2023 |
| JOE Hook Personal Training Ltd | Health & social care | 2019 |
| JOE Lynch Consulting Ltd | Professional & scientific | 2019 |
| JOE Scannell Ltd | Information & communication | 2011 |
| John Hicks' Boat Yard Limited | Transport & logistics | 1957 |
| John Tanous Limited | Manufacturing | 1951 |
| Jointure Management Company Limited | Real estate | 2012 |
| JON Holford Carpentry & Building Ltd | Construction | 2022 |
| Josa Solutions Limited | Manufacturing | 2005 |
| Joza Ltd | Information & communication | 2020 |
| JP Surg Ltd | Health & social care | 2024 |
| JR Electrical Group Ltd | Construction | 2019 |
| JRH Advisory Ltd | Professional & scientific | 2019 |
| JTL DEV Consultancy Ltd | Professional & scientific | 2019 |
| Jujeh UK Ltd | Wholesale & retail | 2011 |
| Julachap Ltd | Health & social care | 2016 |
| Julamani UK Ltd | Real estate | 2018 |
| Julia Ridley Training & Development Ltd | Professional & scientific | 2010 |
| Julian Treyer-Evans & Co Limited | Professional & scientific | 2006 |
| Jump Kiwi Limited | Hospitality | 2024 |
| Junction House Limited | Manufacturing | 2008 |
| Just Plans Limited | Professional & scientific | 2016 |
| Just Thrive Marketing Ltd | Information & communication | 2024 |
| K a R U N Enterprises Ltd | Other services | 2003 |
| K B Samandi Ltd | Hospitality | 2020 |
| K&A Hygienist Services Ltd | Health & social care | 2026 |
| K&S International Investments Ltd | Real estate | 2017 |
| K&T Sullivan Property Ltd | Real estate | 2026 |
| Kaido Industries Ltd | Wholesale & retail | 2021 |