| Instrumentation Concept Limited | Professional & scientific | 2008 |
| Instyle Corporation Limited | Manufacturing | 2010 |
| Insulation and Environmental Services Limited | Construction | 1991 |
| Insurance Training & Marketing Limited | Arts & recreation | 1992 |
| Insure Golf Limited | Arts & recreation | 2003 |
| Insure Holdings Limited | Information & communication | 2016 |
| Insweets Ltd | Wholesale & retail | 2025 |
| Int'L Baller Ltd | Information & communication | 2024 |
| Int-Plus Retail Solutions Ltd | Manufacturing | 2023 |
| Inta Developments Limited | Construction | 2023 |
| Intact Enterprise Ltd | Construction | 2019 |
| Intact IT Solutions Limited | Information & communication | 2016 |
| Intali Limited | Real estate | 2002 |
| Intaline Limited | Wholesale & retail | 2026 |
| Intaprops Limited | Real estate | 2020 |
| Intasound Music Limited | Wholesale & retail | 2011 |
| Intavision Limited | Real estate | 1986 |
| Inteanational Ltd | Hospitality | 2025 |
| Integer Finance Ltd | Administrative & support | 2010 |
| Intego Health Ltd | Professional & scientific | 2019 |
| Integra Technology Solutions Ltd | Administrative & support | 2008 |
| Integrabuild Limited | Construction | 2025 |
| Integral Academy Limited | Education | 2025 |
| Integral Capital Ltd | Real estate | 2019 |
| Integrated Apothec UK Limited | Extraterritorial | 2015 |
| Integrated Computer Utilities Limited | Information & communication | 2001 |
| Integrated Logic Limited | Information & communication | 2013 |
| Integrated Quality Homecare Limited | Health & social care | 2024 |
| Integrated Security and Detective Services Ltd | Administrative & support | 2021 |
| Integrated Support Ltd | Health & social care | 2021 |
| Integrated Tax Solutions Limited | Professional & scientific | 2017 |
| Integrated Treatment Services Ltd | Administrative & support | 2007 |
| Integricare Consultancy Limited | Health & social care | 2025 |
| Integritas Building Group Ltd | Construction | 2025 |
| Integrity Business Finance Limited | Financial services | 2019 |
| Integrity Corporate Finance Limited | Financial services | 2020 |
| Integrity DXB Trading Ltd | Wholesale & retail | 2026 |
| Integrity Glass Limited | Construction | 2022 |
| Integrity Group Enterprises Limited | Financial services | 2020 |
| Integrity Mortgage Solutions Ltd | Financial services | 2013 |
| Integrity Property Holdings Ltd | Real estate | 2017 |
| Intek Design Ltd | Extraterritorial | 2016 |
| Intel Investments Ltd | Real estate | 2024 |
| Intel MEP Limited | Professional & scientific | 2024 |
| Intel Properties Limited | Real estate | 2024 |
| Intellectual Accountancy Limited | Professional & scientific | 2012 |
| Intellectual Accountancy Services Ltd | Information & communication | 2021 |
| Intellenet Consulting Limited | Information & communication | 2015 |
| Intellesec Ltd | Information & communication | 2020 |
| Intellidev Solutions Limited | Information & communication | 2026 |
| Intelligent Adviser Ltd | Financial services | 2017 |
| Intelligent Comfort Group Limited | Wholesale & retail | 2004 |
| Intelligent Mortgages Ltd | Financial services | 2001 |
| Intelligent Networks (GB) Limited | Information & communication | 2008 |
| Intelligent Pest Control Limited | Other services | 2006 |
| Intelligent Vehicle Solutions Ltd | Information & communication | 2019 |
| Intelligentt Property Investmentts Ltd | Real estate | 2024 |
| Intelliresource Ltd | Information & communication | 2018 |
| Intellisphere Solutions Limited | Information & communication | 2025 |
| Intellitgent Group Ltd | Information & communication | 2020 |
| Intellitgent World Ltd | Information & communication | 2025 |
| Inter Care Limited | Water & waste | 1974 |
| Inter Eyecare Optometrists Limited | Wholesale & retail | 1993 |
| Inter Health Link Ltd | Health & social care | 2020 |
| Interact Digital Arts Ltd | Arts & recreation | 2015 |
| Interactive Investments Limited | Real estate | 2014 |
| Interactive Media Group Limited | Wholesale & retail | 2009 |
| Interactive Research Limited | Administrative & support | 2014 |
| Interair Holidays Ltd | Administrative & support | 2024 |
| Intercarlogistics Ltd | Wholesale & retail | 2021 |
| Interface Polymers Ltd | Manufacturing | 2016 |
| Interfacefootwear Ltd | Manufacturing | 2009 |
| Intergalactic Bunny Ltd | Wholesale & retail | 2024 |
| Interglobal Foods Limited | Administrative & support | 2024 |
| Intergrity Healthcare Ltd | Administrative & support | 2014 |
| Interior Design Solutions Leicester Limited | Construction | 2012 |
| Interior Design Solutions Ltd | Manufacturing | 2022 |
| Interior Excellence Ltd | Manufacturing | 2023 |
| Interior Installations Ltd | Construction | 2026 |
| Interior Mode Limited | Wholesale & retail | 2006 |
| Interior Mode Retail Ltd | Manufacturing | 2019 |
| Interiorem Solutions Limited | Extraterritorial | 2022 |
| Interlens Limited | Health & social care | 2023 |
| Interlink Connect UK Ltd | Transport & logistics | 2021 |
| Interlock Fashion Ltd | Wholesale & retail | 2020 |
| International Abrasives Ltd | Wholesale & retail | 2012 |
| International AID Solutions Ltd | Wholesale & retail | 2023 |
| International Arts Centre Limited | Arts & recreation | 1974 |
| International Autograph Auctions Limited | Wholesale & retail | 2005 |
| International Automotive Engineering Projects Limited | Wholesale & retail | 2012 |
| International Express Leicester Limited | Wholesale & retail | 2022 |
| International Furniture Direct Limited | Transport & logistics | 2007 |
| International Islamic College UK Limited | Education | 2025 |
| International Market Leicester Limited | Wholesale & retail | 2020 |
| International Minerals Company Ltd | Wholesale & retail | 2020 |
| International Nails Hair Beauty Academy Ltd | Education | 2018 |
| International Optical Group Ltd | Construction | 2017 |
| International Overseas Ltd | Construction | 2025 |
| International Player Management Ltd | Arts & recreation | 2015 |
| International Selling on Line Ltd | Wholesale & retail | 2022 |