| Interpharmatica Ltd | Professional & scientific | 2023 |
| Interpin Ltd | Information & communication | 2017 |
| Interplay Ltd | Professional & scientific | 2023 |
| Intertec Thermotex Limited | Wholesale & retail | 1999 |
| Into the Elevator Ltd | Information & communication | 2017 |
| Into-Green Ltd | Construction | 2019 |
| Intra-Systems Ltd | Other services | 2021 |
| Intratest Limited | Professional & scientific | 2012 |
| Intrigue Marine Limited | Extraterritorial | 2004 |
| Intrinsic Electrical Services Limited | Construction | 2024 |
| Inventa Partners Limited | Professional & scientific | 2001 |
| Inverclyde House Management Limited | Real estate | 2015 |
| Invergarry Court Limited | Households | 2000 |
| Invertigro (UK) Ltd | Manufacturing | 2025 |
| Invest 44 Holdings Limited | Administrative & support | 2023 |
| Invest 44 Limited | Wholesale & retail | 2020 |
| Invest in Property (Southern) Ltd | Construction | 2016 |
| Investco Ventures Ltd | Wholesale & retail | 2026 |
| Investment 23 Limited | Other services | 2015 |
| Investorestate Ltd | Real estate | 2024 |
| Invstinu L&D Consultancy Limited | Administrative & support | 2021 |
| Iona Court Management Limited | Real estate | 1988 |
| Ionicaniculescu Ltd | Health & social care | 2019 |
| IOT Technologies Ltd | Manufacturing | 2022 |
| Iota Properties Limited | Real estate | 1964 |
| IP Wellness Ltd | Health & social care | 2024 |
| Iplicit Group Limited | Information & communication | 1996 |
| Iplicit Limited | Information & communication | 2010 |
| Ippo Enterprise Ltd | Information & communication | 2025 |
| Ippon Digital Ltd | Information & communication | 2019 |
| Ippon Gym Limited | Arts & recreation | 2012 |
| IPW1 Ltd | Information & communication | 2021 |
| IPW2 Ltd | Wholesale & retail | 2018 |
| IRECRUIT4U Ltd | Administrative & support | 2018 |
| Iron Blue Financials Limited | Administrative & support | 2021 |
| Ironage of Bournemouth Ltd. | Manufacturing | 2003 |
| Irsaliyya Express Ltd | Transport & logistics | 2023 |
| Irving Court Management Company Limited | Households | 1999 |
| IRW Engineering Limited | Professional & scientific | 2012 |
| Isaac Rujumba Photography Ltd | Professional & scientific | 2021 |
| Isaacs House Freehold Limited | Households | 2011 |
| Isaacs Property Developments Ltd | Households | 2023 |
| ISANGO8 Limited | Information & communication | 2015 |
| Iseard & Partners Limited | Construction | 2024 |
| Iseard Holdings Limited | Professional & scientific | 1997 |
| Isecure Security Solutions Ltd | Administrative & support | 2013 |
| ISG Ventilation Ltd | Construction | 2017 |
| Isharajappan Ltd | Health & social care | 2017 |
| Ishka Life Limited | Wholesale & retail | 2023 |
| Isla Must Eats Ltd | Hospitality | 2025 |
| Island Bathrooms Limited | Wholesale & retail | 2000 |
| Islanders Carpentry Limited | Manufacturing | 2022 |
| Ismail Qazi Ltd | Health & social care | 2013 |
| Isobar Properties Limited | Real estate | 1998 |
| Issho Birmingham Limited | Wholesale & retail | 2022 |
| Issho Gateshead Limited | Wholesale & retail | 2022 |
| Issho Limited | Wholesale & retail | 2022 |
| Issho Newcastle Ltd | Wholesale & retail | 2024 |
| Istanbul Bournemouth Food Centre Limited | Wholesale & retail | 2025 |
| Istvan Decorators Ltd | Construction | 2018 |
| Iswitch Electrical Services Ltd | Construction | 2021 |
| IT Certified Limited | Professional & scientific | 2018 |
| IT Drone and Software Services Ltd | Wholesale & retail | 2025 |
| Italian Street Takeaway Limited | Hospitality | 2022 |
| Italimport (Wessex) Limited | Wholesale & retail | 2009 |
| Itavero Ltd | Education | 2005 |
| Iter Technology Limited | Information & communication | 2022 |
| Itstech Ltd | Construction | 2019 |
| Itsy Bitsy Dance Ltd | Arts & recreation | 2022 |
| Ittium Limited | Information & communication | 2004 |
| It’S Built Ltd | Construction | 2024 |
| Iulia Paveliuc Ltd | Health & social care | 2021 |
| IV Health Care Limited | Health & social care | 2023 |
| Ivan 67 Ltd | Construction | 2023 |
| Ivan Crew Limited | Construction | 2014 |
| Ivan Gerov Ltd | Extraterritorial | 2015 |
| Ivatranslogistics Ltd | Construction | 2021 |
| Ivel Corp Ltd | Wholesale & retail | 2022 |
| Iverk PM Ltd | Professional & scientific | 2020 |
| Ivory Avenue Ltd | Wholesale & retail | 2026 |
| IWN Accountancy Limited | Professional & scientific | 2020 |
| IWN Analytics Limited | Information & communication | 2025 |
| IWN Group Ltd | Financial services | 2025 |
| Izaphia Life Ltd | Financial services | 2018 |
| IZI Homes Ltd | Real estate | 2025 |
| Izikumkani Ltd | Wholesale & retail | 2021 |
| Izulu IT Solutions Ltd | Information & communication | 2026 |
| J & C Turner Developments Limited | Construction | 2023 |
| J & C Turner Properties Limited | Real estate | 2009 |
| J & C Wessex Limited | Real estate | 2022 |
| J & J Holdings (Bournemouth) Limited | Real estate | 2022 |
| J & J Perrett Bathrooms Ltd | Construction | 2019 |
| J & L Services Limited | Construction | 2002 |
| J & M Cooperation Limited | Hospitality | 2011 |
| J & N Construction (Dorset) Ltd | Construction | 2026 |
| J & P Properties Limited | Real estate | 1996 |
| J & S Edwards (Designs) Ltd | Professional & scientific | 2025 |
| J a Developers Ltd | Construction | 2010 |
| J Baker Windows & Doors Ltd | Construction | 2025 |
| J Barrow Holdings Limited | Real estate | 2025 |