| Independent Advisers Limited | Extraterritorial | 2012 |
| Independent Living Limited | Construction | 2018 |
| Index Auto Services Ltd | Other services | 2009 |
| Infinitum Financ Limited | Professional & scientific | 2021 |
| Infinitum Financia Limited | Professional & scientific | 2021 |
| Infiverde Limited | Mining & quarrying | 2016 |
| Ingles Advisory Ltd | Information & communication | 2026 |
| Ingleside Consulting Ltd | Professional & scientific | 2010 |
| Ingrid Anderson Ltd | Professional & scientific | 2020 |
| INK on the Lens Limited | Information & communication | 2022 |
| Innoaviate Limited | Information & communication | 2014 |
| Innotech Advisers Limited | Financial services | 1982 |
| Innotech Investments Limited | Administrative & support | 2007 |
| Innovarail Limited | Professional & scientific | 2010 |
| Innovare Dementia Consultancy Limited | Professional & scientific | 2025 |
| Innovation Insight Limited | Information & communication | 2004 |
| Innovex Consulting Ltd | Information & communication | 2020 |
| INOV8 Design & Build Ltd | Construction | 2021 |
| Insight Action Ltd | Information & communication | 2025 |
| Insite Marketing Solutions Limited | Administrative & support | 2001 |
| Inspired Escapes Ltd | Administrative & support | 2023 |
| Inspiring Design Moulding Ltd | Manufacturing | 2023 |
| Integrasure Ltd | Information & communication | 2023 |
| Integrated AV Ltd | Wholesale & retail | 2013 |
| Integrated Education Ltd | Education | 2020 |
| Integrated Heating Services Ltd | Construction | 2020 |
| Integrity Wealth Planning Ltd | Financial services | 2015 |
| Intermac Solutions Ltd | Professional & scientific | 2010 |
| Intermotiv Ltd | Manufacturing | 2010 |
| International Manufacturers Industry Partners Ltd | Wholesale & retail | 2009 |
| International Network for Development Ltd | Professional & scientific | 1998 |
| Intralan Group Limited | Information & communication | 1999 |
| Intrepid Catana Ltd | Real estate | 2020 |
| Inxmedia Limited | Professional & scientific | 2004 |
| Ioni Design Ltd | Professional & scientific | 2024 |
| Ionut Field Ltd | Administrative & support | 2014 |
| Irregular Communications Limited | Professional & scientific | 2015 |
| Irwin Osteopathy Limited | Health & social care | 2015 |
| Ishtiaqsports Limited | Other services | 2025 |
| Isorb Limited | Administrative & support | 2008 |
| Isorb Technology Limited | Water & waste | 1999 |
| IST Global Investment Limited | Real estate | 2026 |
| Iszima Ltd | Administrative & support | 2018 |
| Itarmi 2 Limited | Information & communication | 2017 |
| Itarmi Holdco Limited | Information & communication | 2017 |
| Itarmi Limited | Information & communication | 2016 |
| Itarmi UK Limited | Information & communication | 2015 |
| Itinc Limited | Information & communication | 2022 |
| Ivel Investments Limited | Real estate | 2017 |
| J Decor Interiors Limited | Construction | 1979 |
| J M Gardens Limited | Other services | 2023 |
| J M Wegner Sports Therapy Ltd | Other services | 2022 |
| J P Chef Leatherhead Limited | Hospitality | 2016 |
| J Rogerson Construction Limited | Construction | 2014 |
| J S . Care Limited | Health & social care | 2004 |
| J S C Environmental Services Ltd | Water & waste | 2025 |
| J'S House Nail Ltd | Other services | 2024 |
| J.B.Marr and Company Limited | Real estate | 1962 |
| J.H Projects Limited | Professional & scientific | 2024 |
| J.H. Brill & SON Limited | Construction | 1988 |
| J4C Properties Limited | Real estate | 2025 |
| JAA Cleaning Services Ltd | Administrative & support | 2025 |
| Jade CDM Ltd | Construction | 2021 |
| JAF Cleaning Services Ltd | Transport & logistics | 2023 |
| JAG and Land Surrey Limited | Wholesale & retail | 2019 |
| JAH Project Services Ltd. | Construction | 2016 |
| Jalo Brown Limited | Administrative & support | 2012 |
| Jalyn Limited | Financial services | 2014 |
| JAM Bajan Grenada Holdings Ltd | Administrative & support | 2016 |
| JAM Straight Ltd | Professional & scientific | 2022 |
| James Doddrell Architect Ltd | Professional & scientific | 2007 |
| James Nail Limited | Other services | 2021 |
| James Nightingale Property Ltd | Real estate | 2024 |
| Jamie FOX Planning and Development Limited | Administrative & support | 2011 |
| Jamie Thompson Consulting Ltd | Professional & scientific | 2020 |
| Janala Asset Management Limited | Administrative & support | 1979 |
| Jane Northcote Limited | Professional & scientific | 2010 |
| JAR Property Services Limited | Real estate | 2014 |
| Jasmine & I Constructions Ltd | Construction | 2024 |
| Jasnelle Homes Ltd | Real estate | 2022 |
| Javadoplant Limited | Wholesale & retail | 2019 |
| Jawalker Consulting Ltd | Professional & scientific | 2024 |
| Jaylea Construction Limited | Construction | 2025 |
| JBO Technologies Ltd | Information & communication | 2020 |
| JCK Winchester Limited | Professional & scientific | 2017 |
| JD Electrical Group Ltd | Construction | 2022 |
| JD Real Estate Limited | Real estate | 2019 |
| JDI (UK) | Extraterritorial | 1999 |
| JDM E-Commerce Ltd | Wholesale & retail | 2025 |
| JE Pilates Limited | Professional & scientific | 2016 |
| JE Roofing Specialists Ltd | Construction | 2025 |
| Jeff Musk Ltd | Professional & scientific | 2020 |
| Jefferies Road (West Horsley) Limited | Households | 1997 |
| Jellybean Creative Solutions Limited | Professional & scientific | 1988 |
| Jellybean Creative Solutions Trustees Limited | Professional & scientific | 2024 |
| Jemcom Cctv Limited | Administrative & support | 2009 |
| Jemlee Limited | Other services | 2006 |
| Jenkins Projects Ltd | Construction | 2018 |
| Jeotis Properties Ltd | Real estate | 2021 |
| Jeshla Ltd | Wholesale & retail | 2022 |