| Indian Chef Bawtry Limited | Hospitality | 2026 |
| Indian Cuisine Takeaway Ltd | Hospitality | 2023 |
| Indicate Limited | Education | 2002 |
| Indieprintsco Limited | Wholesale & retail | 2021 |
| Indigo Moss Apparel Limited | Wholesale & retail | 2026 |
| Individual Financial Solutions Limited | Professional & scientific | 2010 |
| Industrial Power Generation Ltd | Manufacturing | 2010 |
| Industrial Power Generators Limited | Manufacturing | 2022 |
| Industrial Property LLP | | 2008 |
| Industrial Vacuum and Systems Limited | Professional & scientific | 2025 |
| Industry Bar & Grill Limited | Hospitality | 2024 |
| Infinity Awnings Limited | Other services | 2021 |
| Infinity Haven Ltd | Real estate | 2024 |
| Infinity Kitchen Designs Limited | Wholesale & retail | 2010 |
| Infinity Production Group Ltd | Arts & recreation | 2024 |
| Infinity Speedsoft Ltd | Arts & recreation | 2022 |
| Information Direct Ltd | Extraterritorial | 2022 |
| Infrastructure Electrical Limited | Construction | 2022 |
| Infrastructure Innovation Partners Ltd | Financial services | 2024 |
| Infusion Plumbing and Heating Ltd | Construction | 2018 |
| Ingenious Foods Limited | Hospitality | 2015 |
| Inhoco 2082 Limited | Professional & scientific | 2000 |
| Inject Group Ltd | Professional & scientific | 2025 |
| Injector Tech Ltd | Wholesale & retail | 2023 |
| Injir Ltd | Wholesale & retail | 2026 |
| Injury Law Chambers Limited | Professional & scientific | 2012 |
| Injury Rehabilitation Care Centre Limited | Health & social care | 2019 |
| INK Architectural Design Ltd | Professional & scientific | 2016 |
| INK Asset Management Limited | Financial services | 2025 |
| INK Projects Ltd | Construction | 2023 |
| INK Rush Limited | Arts & recreation | 2016 |
| Inkfuse Print Academy Ltd | Education | 2026 |
| Inn Pubs PR27 Limited | Hospitality | 2026 |
| Inner Sunshine C.I.C. | Education | 2020 |
| Innes Consultancy and Enterprise Ltd | Professional & scientific | 2018 |
| Innovation Tech Solutions Limited | Real estate | 2014 |
| Innovative Cloud Services Ltd | Information & communication | 2015 |
| Innovative Constructions Solution Ltd | Manufacturing | 2024 |
| Innovative Seven Continents for Advanced Dimensions Ltd | Financial services | 2025 |
| Innovaxin Ltd | Administrative & support | 2020 |
| Innovo Agency Limited | Professional & scientific | 2025 |
| Innspark Leisure PR26 Limited | Hospitality | 2025 |
| INO Healthcare Ltd | Health & social care | 2026 |
| Inpixels Ltd | Information & communication | 2013 |
| Inreach Investments Ltd | Real estate | 2021 |
| Insab Property Ltd | Real estate | 2025 |
| Insagro Ltd | Other services | 2024 |
| Insbo Group Ltd | Construction | 2023 |
| Insbo Ltd | Administrative & support | 2023 |
| Inshot Limited | Real estate | 1988 |
| Inshriach Property Services Ltd | Real estate | 2022 |
| Inside Joke Ltd | Arts & recreation | 2021 |
| Insight Psychological Therapies Limited | Health & social care | 2024 |
| Insight Traffic Solutions Ltd | Construction | 2022 |
| Inspektor Technologies Ltd | Information & communication | 2008 |
| Inspirations Hair & Beauty (Doncaster) Limited | Other services | 2018 |
| Inspire Digital Media Ltd | Professional & scientific | 2016 |
| Inspire Doncaster Ltd | Health & social care | 2022 |
| Inspire Side by Side CIC | Health & social care | 2026 |
| Inspire Skills Training Ltd | Other services | 2016 |
| Inspired Fitting Services Limited | Construction | 2025 |
| Inspiro Learning Limited | Education | 2012 |
| Install a Manchester Ltd | Construction | 2022 |
| Instant Build Limited | Administrative & support | 2004 |
| Instassist Limited | Extraterritorial | 2022 |
| Instrument Installations Limited | Manufacturing | 1988 |
| Intake Community Enterprise Ltd | Arts & recreation | 2002 |
| Intake Local Ltd | Wholesale & retail | 2019 |
| Intake Logistics Ltd | Administrative & support | 2023 |
| Intec Office Holdings Limited | Financial services | 2023 |
| Intec Office Systems Limited | Wholesale & retail | 2002 |
| Integral Care Services Ltd | Administrative & support | 2014 |
| Integrated Automation Ltd | Professional & scientific | 2018 |
| Integrated Energy Solutions Ltd | Construction | 2010 |
| Integrated Fitness Ltd | Other services | 2026 |
| Integrated Waste Management Limited | Water & waste | 1989 |
| Integrating Technology Ltd | Extraterritorial | 2022 |
| Integrel Recruitment Ltd | Administrative & support | 2025 |
| Inteknix Limited | Administrative & support | 2012 |
| Intellidrift Ltd | Information & communication | 2026 |
| Intelligent AV & Electrical Ltd | Construction | 2011 |
| Intelligent Patient Records Ltd | Information & communication | 2021 |
| Intelligent Synthesis Ltd | Information & communication | 2024 |
| Intellisoft Ltd | Information & communication | 2019 |
| Interactiva Ltd | Information & communication | 2024 |
| Interapptiv Limited | Information & communication | 2021 |
| Interfix Holdings Ltd | Wholesale & retail | 2024 |
| Interfix Supplies Ltd | Wholesale & retail | 2025 |
| Interim FD Resources Ltd | Professional & scientific | 2025 |
| Interior Contract Specialists Limited | Construction | 1999 |
| Interior Fit OUT Solutions UK Group Ltd | Construction | 2021 |
| Interiors Drywall & Celling Finishing Ltd | Construction | 2016 |
| Interiors.Family Limited | Professional & scientific | 2021 |
| Interlec Group Ltd. | Manufacturing | 2017 |
| Interloom Ltd | Administrative & support | 2011 |
| International Art Services Ltd | Transport & logistics | 2018 |
| International Challenge Racing Limited | Information & communication | 1998 |
| International Corporate Training Limited | Education | 2015 |
| International Dovetail Limited | Extraterritorial | 2026 |
| International Formations Limited | Extraterritorial | 2016 |