| Imperial Roofing Solutions Ltd | Construction | 2023 |
| Impexo Logistics Ltd | Transport & logistics | 2025 |
| Impulse Business Solutions Limited | Professional & scientific | 2003 |
| Impulse Technologies UK Ltd | Information & communication | 2007 |
| Incto Supplies Limited | Manufacturing | 2025 |
| IND Enterprises Ltd | Wholesale & retail | 2021 |
| Indef Systems Ltd | Information & communication | 2010 |
| India's Gourmet Restaurant Ltd | Hospitality | 2019 |
| Indian Bridal Dresss Ltd | Wholesale & retail | 2014 |
| Indian Cuisine Restaurant Ltd | Hospitality | 2020 |
| Indigo Index Limited | Wholesale & retail | 2023 |
| Indiguard Security Ltd | Administrative & support | 2025 |
| Indinest Limited | Wholesale & retail | 2026 |
| Indo Direct Foods Ltd | Wholesale & retail | 2008 |
| Indus Bridge Supply Ltd | Wholesale & retail | 2026 |
| Indus IT Solutions Limited | Information & communication | 2025 |
| Indus Services Limited | Information & communication | 2006 |
| Industrial Rope Access Ltd | Manufacturing | 2025 |
| Infinity Analytics Ltd | Information & communication | 2026 |
| Infinity App Investments Ltd | Real estate | 2022 |
| Infinity App Systems Limited | Information & communication | 2013 |
| Infinity Wholesale Ltd | Wholesale & retail | 2023 |
| Infinitz Solutions Ltd. | Information & communication | 2016 |
| Infitiny Ltd | Manufacturing | 2020 |
| Infologix IT Services Ltd | Information & communication | 2013 |
| Infortech Global Limited | Information & communication | 2025 |
| Infosis Consultancy Ltd | Other services | 2018 |
| Infosquare Solutions Limited | Information & communication | 2007 |
| Infra Properties Limited | Construction | 2017 |
| Infutech Consultancy Limited | Other services | 2018 |
| Ingenuus Holdings Ltd | Other services | 2023 |
| Inhire Ltd | Construction | 2023 |
| Inhvincible Ltd | Construction | 2018 |
| Initfinity Ltd | Information & communication | 2008 |
| Initialise Group Ltd | Construction | 2026 |
| Inn Networks Ltd | Information & communication | 2014 |
| Innolentra Ltd | Information & communication | 2025 |
| Innova Academy Ltd | Education | 2021 |
| Innovative Devices UK Limited | Information & communication | 2008 |
| Innovigence Limited | Wholesale & retail | 2024 |
| Innovio Limited | Information & communication | 2024 |
| Inovx Ltd | Administrative & support | 2024 |
| Insight Staffing Limited | Administrative & support | 2019 |
| Inspiration on Demand Ltd | Real estate | 2022 |
| Inspiration Solutions Ltd | Information & communication | 2020 |
| Inspire Brokers Limited | Financial services | 2017 |
| Inspire Connect College & Recruitment Ltd | Administrative & support | 2017 |
| Inspire Middlesex College Ltd | Education | 2012 |
| Inspire Path Properties Ltd | Real estate | 2025 |
| Inspire Real Estate Ltd | Real estate | 2026 |
| Inspired Sustainable Homes Ltd | Construction | 2025 |
| Instant Care Property Management Ltd | Real estate | 2025 |
| Instant Care Solutions Limited | Health & social care | 2009 |
| Instant Care Supported Housing Ltd | Hospitality | 2019 |
| Instant L Limited | Information & communication | 2024 |
| Insure the Risk Ltd | Extraterritorial | 2016 |
| Intech Pro Ltd | Wholesale & retail | 2021 |
| Integrate Solutions Limited | Professional & scientific | 2012 |
| Integrated Software Design Solutions Ltd | Information & communication | 2015 |
| Integrated Software Development Ltd | Information & communication | 2009 |
| Integritas Talent Ltd | Professional & scientific | 2016 |
| Intellectual Consultancy Services Limited | Extraterritorial | 2011 |
| Intelligent Partners Ltd | Administrative & support | 2025 |
| Intelligentized Cyber Ltd | Information & communication | 2026 |
| Intelliquest Solutions Limited | Information & communication | 2011 |
| Inter-Kurd Solutions Ltd | Real estate | 2023 |
| Interior Printing Ltd | Construction | 2025 |
| Interiors of London Limited | Wholesale & retail | 2017 |
| Intermediate Steps Ltd | Real estate | 2026 |
| Intermix Supplies Ltd | Wholesale & retail | 2016 |
| Internal Beauty Ltd | Wholesale & retail | 2023 |
| International Trading Partners Ltd | Manufacturing | 2025 |
| International Trading Company Limited | Information & communication | 2014 |
| Intigriti Solutions Limited | Information & communication | 2012 |
| Intricate Designn Ltd | Professional & scientific | 2022 |
| Inturi Consulting Ltd | Information & communication | 2012 |
| Inugami Limited | Manufacturing | 2015 |
| Inventx Limited | Manufacturing | 2021 |
| Invest Wealth Ltd | Real estate | 2024 |
| Investco London Ltd | Real estate | 2019 |
| Investment Property London Ltd | Real estate | 2020 |
| Investments R US Ltd | Real estate | 2025 |
| Invidia Ltd | Construction | 2019 |
| Invinzo Limited | Wholesale & retail | 2019 |
| Invista Properties Ltd | Real estate | 2025 |
| Inwood Logistics Limited | Transport & logistics | 2005 |
| Inwood Projects 1 Limited | Real estate | 2023 |
| Inwood Projects Limited | Real estate | 2016 |
| Inwood Road House Management RTM Company Ltd | Households | 2019 |
| Iocean Technologies Ltd | Information & communication | 2014 |
| Ioco Food Ltd | Wholesale & retail | 2024 |
| Iomega Limited | Information & communication | 2025 |
| Ionize Tech Limited | Transport & logistics | 2020 |
| Iosl Ltd | Construction | 2023 |
| Iotec Ltd | Information & communication | 2010 |
| Ipark Secure Limited | Professional & scientific | 2012 |
| Iperformance Cars Ltd | Administrative & support | 2017 |
| IQ Engineering Ltd | Professional & scientific | 2022 |
| Iqan Logistics Limited | Transport & logistics | 2022 |
| Iqan Pallets Limited | Manufacturing | 2023 |