| Intela (Europe) Chemical Industry Co., Ltd | Extraterritorial | 2024 |
| Intellibase Limited | Information & communication | 2024 |
| Intellicene Software UK Limited | Information & communication | 2020 |
| Intelligent Fingerprinting Limited | Professional & scientific | 2007 |
| Intelligent Infrastructure Solutions Ltd | Administrative & support | 2017 |
| Intelligent Medprep Ltd | Information & communication | 2023 |
| Intelliject Limited | Information & communication | 2025 |
| Intelliquest Tech Solutions Ltd | Information & communication | 2024 |
| Intellistream Private Limited | Information & communication | 2026 |
| Intent* Brand Work Limited | Professional & scientific | 2024 |
| Intent.Ly Global Limited | Administrative & support | 2009 |
| Intentional Impact Limited | Professional & scientific | 2013 |
| Inter Urban Studios Limited | Professional & scientific | 2010 |
| Inter-Leadco Ltd | Public administration | 2025 |
| Inter-Let (Cambridge) LLP | | 2015 |
| Interact BIO Ltd | Professional & scientific | 2023 |
| Interaction Magic Ltd | Professional & scientific | 2020 |
| INTERBEST77 Ltd | Manufacturing | 2025 |
| Intercollegiate Services Limited | Education | 2009 |
| Interdisciplinary Climate Economics for Nature and Society LAB CIC | Professional & scientific | 2024 |
| Interface Technologies (UK) Ltd | Professional & scientific | 2024 |
| Intergence Systems Limited | Information & communication | 2003 |
| Interglobe Holding Limited | Information & communication | 2026 |
| Interim MGT Ltd | Construction | 2019 |
| Interior Intent Limited | Wholesale & retail | 2021 |
| Interior Solution (Cambridge) Ltd | Construction | 2026 |
| Interlace Blinds Limited | Construction | 2019 |
| Interlinkt Limited | Information & communication | 2017 |
| International Aircraft Limited | Manufacturing | 2015 |
| International Anti-Aging Medicine Development Association | Extraterritorial | 2025 |
| International Association for Applied Econometrics | Education | 2011 |
| International Chinese Coach Association | Professional & scientific | 2025 |
| International Development Company Limited | Real estate | 2002 |
| International EYE Care and Health Association | Extraterritorial | 2025 |
| International Friends Limited | Transport & logistics | 2002 |
| International Hair Follicle and Hair Ecological Health Association | Extraterritorial | 2025 |
| International In-House Counsel Journal Limited | Other services | 2007 |
| International Lean SIX Sigma Academy Ltd | Education | 2017 |
| International Longevity Medicine Alliance Limited | Wholesale & retail | 2026 |
| International Longevity Science & Research Association | Education | 2025 |
| International Puridea Co., Ltd. | Wholesale & retail | 2023 |
| International Renal Interest Society Ltd. | Professional & scientific | 2016 |
| International Silk Road Organisation | Information & communication | 2023 |
| International Society of Menopause Health Association | Extraterritorial | 2025 |
| International T & a Management Ltd | Administrative & support | 2017 |
| International Trade Consulting Limited | Wholesale & retail | 2025 |
| Internet Watch Foundation | Information & communication | 1997 |
| Internet Watch Limited | Information & communication | 1996 |
| Interplay Innovations Ltd | Information & communication | 2024 |
| Interpretatus Consulting Ltd | Information & communication | 2015 |
| Interref Ltd | Arts & recreation | 2024 |
| Interstate Craft Brewing Company Limited | Manufacturing | 2016 |
| Interstice Limited | Professional & scientific | 2024 |
| Intertranslations Ltd | Professional & scientific | 2011 |
| Inti Construction Ltd | Construction | 2014 |
| Intimesec Ltd. | Wholesale & retail | 2026 |
| Intra BS Ltd | Information & communication | 2018 |
| Intract Pharma Limited | Professional & scientific | 2015 |
| Intraresilience Limited | Professional & scientific | 2019 |
| Intrida Limited | Information & communication | 2018 |
| Intrstlr Limited | Extraterritorial | 2023 |
| Intruder & Fire Alarms Cambridge Limited | Construction | 2013 |
| Intue Ltd | Arts & recreation | 2016 |
| Invariance Holdings Ltd | Financial services | 2022 |
| Invensys Copper Fetobar. Ltd | Manufacturing | 2025 |
| Invent Circle CIC | Education | 2023 |
| Invent Vision Ltd | Transport & logistics | 2025 |
| Invention Works Limited | Professional & scientific | 2009 |
| Inventivity Limited | Other services | 1996 |
| Inventoryclerk Cambridge Limited | Administrative & support | 2009 |
| Inventureco Ltd | Real estate | 2022 |
| Invest 4 Impact Ltd | Professional & scientific | 2025 |
| Invest in Open UK Limited | Professional & scientific | 2026 |
| Investaura Limited | Information & communication | 2012 |
| Invested Investor Limited | Information & communication | 2018 |
| Investuccino Ltd | Professional & scientific | 2014 |
| Investure Group Limited | Financial services | 2019 |
| Inveswei Limited | Information & communication | 2025 |
| Invictus Fire Safety Ltd | Public administration | 2018 |
| Invigilatis Limited | Information & communication | 2012 |
| Invisible Stuff Ltd | Professional & scientific | 2013 |
| Invisible.Ac Limited | Manufacturing | 2002 |
| Inviso Consulting Limited | Professional & scientific | 2013 |
| Invisotech Limited | Professional & scientific | 2021 |
| Inviteq Polymer Technology Limited | Professional & scientific | 2018 |
| Invokore Limited | Information & communication | 2026 |
| Invu Communications Limited | Information & communication | 2006 |
| Invu Networks Limited | Information & communication | 2012 |
| Invumedia Group Limited | Information & communication | 2018 |
| Inzyra Ltd | Professional & scientific | 2025 |
| Iomi Ltd | Information & communication | 2025 |
| Iona Logistics Ltd | Manufacturing | 2021 |
| Ionela Motorsport Ltd | Manufacturing | 2023 |
| Ionscope Limited | Manufacturing | 2019 |
| Ionut Aviation Ltd | Manufacturing | 2024 |
| Iordache a. Dragos Ltd | Manufacturing | 2025 |
| Iordachi Danu Limited | Manufacturing | 2026 |
| IORDAN29 Ltd | Manufacturing | 2025 |
| Iorsen Management Ltd | Professional & scientific | 2017 |
| IOT & Approval Solutions Limited | Professional & scientific | 2003 |