| Intelligence Forge LLP | | 2026 |
| Intelligent Logistics Services Europe (HGV) Limited | Extraterritorial | 2012 |
| Intelligent Logistics Services Ltd | Wholesale & retail | 2011 |
| Intelligent Pioneering Solutions Ltd | Professional & scientific | 2016 |
| Intelligent Plumbing & Heating Ltd | Construction | 2018 |
| Intelligent Procurement Limited | Information & communication | 2019 |
| Intelligent Scaffolding Ltd | Construction | 2018 |
| Intelligent Targeting Limited | Professional & scientific | 2024 |
| Intellihep Ltd | Professional & scientific | 2002 |
| Intense Sculpt Ltd | Health & social care | 2025 |
| Intensity Sports CIC | Arts & recreation | 2025 |
| Inter Regulatory Limited | Professional & scientific | 2024 |
| Inter Scientific Limited | Professional & scientific | 2017 |
| Inter-Leisure Group Ltd | Wholesale & retail | 2006 |
| Interactive Beers Ltd | Wholesale & retail | 2025 |
| Interactive Lawyers Ltd | Professional & scientific | 2019 |
| Interbets Limited | Financial services | 1996 |
| Interbuild Distribution (UK) Ltd. | Wholesale & retail | 2020 |
| Intercaps Ltd | Wholesale & retail | 2015 |
| Interchange Motors Ltd | Wholesale & retail | 2023 |
| Interconnect IT Limited | Information & communication | 1996 |
| Interconnect Telecoms Ltd | Information & communication | 2023 |
| Intercontinental Textile Ltd | Wholesale & retail | 2026 |
| Interface Interiors Ltd | Construction | 2020 |
| Interfreight Services Limited | | 1983 |
| Interfurn Consulting Limited | Professional & scientific | 2016 |
| Intergen Financial Planning Limited | Financial services | 2021 |
| Interim Solution (NW) Postie Ltd | Wholesale & retail | 2020 |
| Interiofy Ltd | Information & communication | 2021 |
| Interior Project Contracts Limited | Construction | 2024 |
| Interior Psychologist Limited | Professional & scientific | 2022 |
| Interior Solutions (Contractors) Ltd | Construction | 2018 |
| Interiors for ALL Ltd | Wholesale & retail | 2022 |
| Interlink Scaffolding Liverpool Limited | Construction | 2025 |
| Intermission Headwear Ltd | Wholesale & retail | 2025 |
| International Academy for Higher Studies Ltd | Education | 2024 |
| International Beauty Academy Limited | Education | 2016 |
| International Container Hubs (Scapa) Limited | Construction | 2022 |
| International Container Hubs Limited | Extraterritorial | 2002 |
| International Corporate Services Ltd | Extraterritorial | 2025 |
| International Cotton Association Mutual Limited | Other services | 2015 |
| International Environmental Management Limited | Professional & scientific | 2011 |
| International Food Store Itoro Ltd | Wholesale & retail | 2021 |
| International Food Store Liverpool Ltd | Wholesale & retail | 2025 |
| International Garage Limited | Wholesale & retail | 2018 |
| International Innovation Hub Limited | Professional & scientific | 2016 |
| International Marine Certification Society | Professional & scientific | 2020 |
| International Network of Gatekeepers (Inog) Ltd | Other services | 2020 |
| International School of Aesthetics Limited | Education | 2024 |
| International School of Compliance and Regulation Ltd | Professional & scientific | 2023 |
| International Skincare Education (UK) Limited | Education | 2025 |
| International Space City Ltd | Administrative & support | 2020 |
| International Trading & Business Ltd | Hospitality | 2026 |
| International Translations Limited | Professional & scientific | 1983 |
| International UK Food Store Ltd | Wholesale & retail | 2019 |
| Internet Investigation Solutions Ltd | Information & communication | 2014 |
| Internet of Things Limited | Information & communication | 2012 |
| Interpart Resources Ltd | Extraterritorial | 2001 |
| Interplanetary Ltd | Professional & scientific | 2014 |
| Interpreting,Translation and Consultancy Ltd | Information & communication | 2019 |
| Intersky Commercial Enterprises Limited | Hospitality | 2025 |
| Interstadia Digital Limited | Information & communication | 2015 |
| Interstadia Limited | Information & communication | 2009 |
| Interstellar Global CIC | Manufacturing | 2022 |
| Intertek Technical Services Holdings Limited | | 1978 |
| Intervention Pathways Limited | Hospitality | 2026 |
| Interviewonline Limited | Other services | 2013 |
| Interweld Limited | Manufacturing | 2020 |
| Inthawong Properties Limited | Real estate | 2024 |
| Intimate Auto Trading Limited | Wholesale & retail | 2023 |
| Into OUR World Childminding Ltd | Health & social care | 2025 |
| Intogreat Ltd | Other services | 2021 |
| Intrasurge Medical Ltd | Administrative & support | 2022 |
| Intre Group Limited | Administrative & support | 2021 |
| Intrepid Engineering Ltd | Other services | 2024 |
| Intricata Limited | Information & communication | 2004 |
| Intricate Care Solutions Ltd | Health & social care | 2026 |
| Intrinsic Audio Ltd | Administrative & support | 2023 |
| Intuita Property Investments Ltd | Construction | 2018 |
| Intuitecture Limited | Information & communication | 2014 |
| Intunique Developments Ltd | Construction | 2019 |
| Intx Cars (UK) Limited | Transport & logistics | 2004 |
| Invabuild Project Management Ltd | Construction | 2023 |
| Invascular ETT Ltd | Health & social care | 2024 |
| Invenio Group Limited | Professional & scientific | 2017 |
| Inventive Apps Ltd | Information & communication | 2026 |
| Inverclyde Management Limited | Households | 1979 |
| Invest Group Holdings Ltd | Financial services | 2025 |
| Invest Group Ltd | Real estate | 2020 |
| Invest in Bricks & Mortar Ltd | Real estate | 2024 |
| Invest in Property Assets Ltd | Real estate | 2020 |
| INVEST8 Limited | Real estate | 2017 |
| INVEST9 Ltd | Real estate | 2024 |
| Investigations Academy Ltd | Administrative & support | 2021 |
| Investment Connections Limited | Financial services | 2003 |
| Investment Prime Properties Ltd | Real estate | 2022 |
| Investment Property Sales Limited | Administrative & support | 2011 |
| Investments Daniel House Ltd | Financial services | 2018 |
| Investments RB Limited | Professional & scientific | 2018 |
| Investments Stability Ltd | Extraterritorial | 2015 |