| Integral Financial Planning Ltd | Financial services | 2014 |
| Integral Partner CH Ltd | Professional & scientific | 2024 |
| Integral Stone Limited | Construction | 2025 |
| Integral Transport & Warehousing Ltd | Transport & logistics | 2020 |
| Integral Transport Services Limited | Transport & logistics | 2012 |
| Integral Utilities and Civils Ltd | Construction | 2022 |
| Integrate Associates Ltd | Professional & scientific | 2021 |
| Integrate Home Limited | Construction | 2017 |
| Integrated Buildings Limited | Information & communication | 2023 |
| Integrated Contact Solutions Limited | Administrative & support | 2016 |
| Integrated Events Ltd | Professional & scientific | 2022 |
| Integrated Healthcare Ltd | Information & communication | 2017 |
| Integrated Life Science Group Ltd | Professional & scientific | 2020 |
| Integrated Managed Services Ltd | Administrative & support | 2017 |
| Integrated Manufacturing Group Limited | Financial services | 2009 |
| Integrated Skills Holdings Limited | Professional & scientific | 2012 |
| Integrated Skills Limited | Administrative & support | 1993 |
| Integrated Skills Trustees Limited | Other services | 2021 |
| Integrated Supplies Solutions (ISS) Ltd | Wholesale & retail | 2026 |
| Integrity Financial Management (Holdings) Ltd | Financial services | 2023 |
| Integrity Financial Management Limited | Administrative & support | 2004 |
| Integro Estates Ltd | Real estate | 2023 |
| Integrum Private Limited | Administrative & support | 2017 |
| Intellassure Ltd | Professional & scientific | 2024 |
| Intellete Consultancy Ltd | Education | 2024 |
| Intelligent Appliances Limited | Wholesale & retail | 2020 |
| Intelligent Delivery Operations Group Limited | Financial services | 2016 |
| Intelligent Delivery Solutions Ltd | Information & communication | 2015 |
| Intelligent Formations Ltd | Extraterritorial | 2023 |
| Intelligent Funding Ltd | Financial services | 2025 |
| Intelligent Interaction Ltd. | Extraterritorial | 2020 |
| Intelligent Property Marketing Ltd | Professional & scientific | 2024 |
| Intelligentme Ltd | Information & communication | 2024 |
| Intellilex Ltd | Information & communication | 2017 |
| Intellipath Limited | Information & communication | 2024 |
| Intellisaas Systems Limited | Professional & scientific | 2025 |
| Intellistart Limited | Professional & scientific | 2018 |
| Intellisynth Ltd | Information & communication | 2012 |
| Intelliwarmth Technologies Ltd | Information & communication | 2025 |
| Intelskin Academy Limited | Education | 2025 |
| Intempo Electrical Contracting Limited | Construction | 2020 |
| Intensive Medical Events Ltd | Education | 2025 |
| Intent Crystals Limited | Wholesale & retail | 2024 |
| Intenwatch Ltd | Professional & scientific | 2010 |
| Inteq Services (Holdings) Ltd | Financial services | 2008 |
| Inteq Services Ltd. | Administrative & support | 2008 |
| Inteqa Limited | Extraterritorial | 2015 |
| Inteqniq Ltd | Construction | 2014 |
| Inter Face IP Ltd | Financial services | 2019 |
| Inter Hire (Ptvc) Limited | Administrative & support | 2019 |
| Inter House Windows Ltd | Construction | 2010 |
| Inter Vehicle Group Ltd | Financial services | 2013 |
| Interactions Speech and Language Therapy Ltd | Health & social care | 2021 |
| Interbox Limited | Transport & logistics | 2017 |
| Intercash Holdings UK Limited | Administrative & support | 2020 |
| Intercash Prepaid Limited | Administrative & support | 2013 |
| Intercil Limited | Professional & scientific | 2020 |
| Intercity Accommodation LLP | | 2025 |
| Intercity Glazing Systems Limited | Wholesale & retail | 1988 |
| Interdict Limited | Information & communication | 2012 |
| Interev Limited | Wholesale & retail | 2019 |
| Interface Resource Solutions Ltd | Administrative & support | 2011 |
| Interim Food Services Limited | Professional & scientific | 2016 |
| Interim Management Services (Yorkshire) Ltd | Professional & scientific | 2010 |
| Interim Partners Limited | Administrative & support | 2002 |
| Interior Blinds Limited | Wholesale & retail | 2006 |
| Interior DZ Ltd | Professional & scientific | 2021 |
| Interiors 4 Living Ltd | Wholesale & retail | 2010 |
| Interlandi Properties Ltd | Real estate | 2023 |
| Interlink Security Services Limited | Administrative & support | 2008 |
| Intermediation Group Limited | Professional & scientific | 1996 |
| Internal Audit Taskforce Limited | Professional & scientific | 2006 |
| Internal Logic Games Limited | Information & communication | 2020 |
| International Airport Bidco Limited | Administrative & support | 2017 |
| International Association of Civil Aviation Chaplains CIC | Other services | 2019 |
| International Board for Citizenship, Residency and Education Abroad Ltd | Professional & scientific | 2015 |
| International Camp Suisse Ltd | Education | 2011 |
| International Cleaning Services Ltd | Administrative & support | 2025 |
| International Council for Coaching Excellence | Arts & recreation | 2014 |
| International Eatery Ltd | Hospitality | 2026 |
| International Environmental Testing Group Limited | Professional & scientific | 2011 |
| International Food Magazine Limited | Wholesale & retail | 2019 |
| International Foods Leeds Limited | Wholesale & retail | 2015 |
| International Grocers (Leeds) Ltd | Wholesale & retail | 2020 |
| International Lighting Limited | Wholesale & retail | 2001 |
| International Line Resources Limited | Professional & scientific | 2024 |
| International Line Services Limited | Construction | 2019 |
| International LUX Properties Ltd | Real estate | 2025 |
| International Master Services Ltd | Transport & logistics | 2020 |
| International Personal Finance Investments Limited | Professional & scientific | 1969 |
| International Personal Finance PLC | Financial services | 2006 |
| International Procurement and Logistics Limited | Wholesale & retail | 2004 |
| International Professional Platform Ltd | Administrative & support | 2018 |
| International Project Management Ltd | Information & communication | 2022 |
| International School of Linguists Limited | Administrative & support | 2013 |
| International Security Deposits Ltd. | Mining & quarrying | 2015 |
| International Store 25 Ltd | Wholesale & retail | 2026 |
| International Store Leeds Ltd | Wholesale & retail | 2025 |
| International Student Guidance Services Ltd | Professional & scientific | 2024 |
| International Teaching Learning Assessment Consultants and Online Schools Limited | Education | 2024 |