| IM Xpress Ltd | Wholesale & retail | 2023 |
| Image Furnishings Limited | Wholesale & retail | 2019 |
| Imagination Bay Cafe Ltd | Hospitality | 2024 |
| Impact Specialist Joinery and Building Services Limited | Construction | 2004 |
| Imperial Furniture Group Limited | Professional & scientific | 2006 |
| Imperial Office Furniture Ltd | Manufacturing | 1999 |
| Imperial Technology Limited | Professional & scientific | 2020 |
| Imperium Media Enterprise Ltd | Information & communication | 2025 |
| Implement Consultancy Limited | Professional & scientific | 2011 |
| Importance Limited | Other services | 2019 |
| Impress Ltd | Professional & scientific | 2025 |
| Improvair Limited | Manufacturing | 2010 |
| Impulse Stores Ltd | Wholesale & retail | 2019 |
| IMR Services Limited | Professional & scientific | 2006 |
| IN River Hydro Limited | Manufacturing | 2013 |
| IN Trans Ltd | Transport & logistics | 2026 |
| In-Floor Superstore Ltd | Wholesale & retail | 2023 |
| Inam Concepts Ltd | Information & communication | 2019 |
| Inchlonaig Limited | Real estate | 2022 |
| Include ME C.I.C. | Other services | 2013 |
| Incomeguard Ltd | Financial services | 2004 |
| Incredible Dog Shower Ltd | Manufacturing | 2025 |
| Indent (Bury) Limited | Health & social care | 2019 |
| Independent Financial Advisor Limited | Financial services | 2004 |
| Independent Plant Management Limited | Wholesale & retail | 1997 |
| Indi Travel Guide Ltd | Administrative & support | 2022 |
| Indigo Buffet Ltd | Hospitality | 2024 |
| Indigo Contractor Services Limited | Administrative & support | 2011 |
| Indigo GP Locums Limited | Extraterritorial | 2011 |
| Indigo Innovations Ltd | Information & communication | 2025 |
| Indigo Mango Ltd | Information & communication | 2007 |
| Indigo Medical Recruitment Limited | Administrative & support | 2007 |
| Indigo Medico-Legal Ltd | Health & social care | 2021 |
| Industria Energy UK Limited | Information & communication | 2014 |
| Industria Sports Promotions Ltd | Professional & scientific | 2025 |
| Industrial Art Limited | Professional & scientific | 2007 |
| INF Retailers Limited | Wholesale & retail | 2018 |
| Infinities Retail Group Holdings Limited | Professional & scientific | 2015 |
| Infinities Retail Group Limited | Wholesale & retail | 2011 |
| Infinity 1/0 Ltd | Financial services | 2023 |
| Infinity Commerce Ltd | Wholesale & retail | 2024 |
| Infinity HR Ltd | Administrative & support | 2024 |
| Infinity North Clothing Ltd. | Wholesale & retail | 2016 |
| Infinity North Ltd | Construction | 2021 |
| Infralogics Limited | Professional & scientific | 2009 |
| Ingen Strategies Limited | Administrative & support | 2021 |
| Inivea Limited | Real estate | 2010 |
| INK Make UP Ltd | Other services | 2015 |
| Inline Developments & Renovations Limited | Construction | 2024 |
| Inner YOU Yoga and Reiki Limited | Professional & scientific | 2010 |
| Innerhot Ltd | Hospitality | 2022 |
| Innovation Hospitality Limited | Hospitality | 2025 |
| Innovationinside International Limited | Professional & scientific | 2023 |
| Innovationinside Limited | Professional & scientific | 2014 |
| Innovative Care Solutions Ltd | Health & social care | 2025 |
| Innovative Design Technologies (UK) Limited | Professional & scientific | 2010 |
| Innovelox Ltd | Information & communication | 2026 |
| Inova App Limited | Professional & scientific | 2024 |
| Inphase Technical Limited | Construction | 2024 |
| Inquisitive Investigations Ltd | Administrative & support | 2023 |
| INS Law Ltd | Professional & scientific | 2020 |
| Inside the Lines Ltd | Information & communication | 2025 |
| Insight Investing Ltd | Professional & scientific | 2024 |
| Inspection Team Limited | Construction | 2014 |
| Inspire Agency Limited | Professional & scientific | 2016 |
| Inspiro Kitchen Ltd | Professional & scientific | 2023 |
| Inspiro Property Ltd | Real estate | 2026 |
| Installation Services (NW) Limited | Construction | 2020 |
| Installer Solutions Ltd | Construction | 2020 |
| Instant Solution Limited | Wholesale & retail | 2009 |
| Instantina Flavours Ltd | Manufacturing | 1992 |
| Insure My Business (NW) Ltd | Financial services | 2012 |
| Integral Healthcare Partnership Limited | Health & social care | 2005 |
| Integral NDT Ltd | Professional & scientific | 2020 |
| Integraspec ICF Solutions Ltd | Construction | 2024 |
| Intelconsultancy Ltd | Professional & scientific | 2017 |
| Intelligent Fleet Management Limited | Financial services | 2009 |
| Intelligent Labs Ltd | Information & communication | 2026 |
| Intelligent Solutions (UK) Limited | Information & communication | 2014 |
| Interactive MCR Ltd | Wholesale & retail | 2017 |
| Interalign Organisation Limited | Professional & scientific | 1999 |
| Interior Plant Decor Limited | Administrative & support | 2003 |
| Interiors of Cheshire Limited | Wholesale & retail | 2019 |
| Interiors Plus Limited | Professional & scientific | 2004 |
| International Admissions Ltd | Education | 2025 |
| International Help &Consulting Foundation | Other services | 2025 |
| International Help Foundation | Health & social care | 2020 |
| International Marketing Strategies Ltd | Professional & scientific | 2024 |
| Intersmart Media Limited | Administrative & support | 2012 |
| Intimate Memories Ltd | Professional & scientific | 2022 |
| Into Independence Limited | Administrative & support | 2012 |
| Intradermean Ltd | Administrative & support | 2018 |
| Intrend Bathrooms Ltd | Construction | 2013 |
| Intrend Property Services Ltd | Construction | 2024 |
| Intrinsic Law Ltd | Professional & scientific | 2019 |
| Introducing Excellence Limited | Administrative & support | 2019 |
| Invasive NON Native Specialists Assn | Other services | 2016 |
| Invasive Species Impact Assessment Ltd | Extraterritorial | 2025 |
| Invenio Stiftung | Other services | 2017 |
| Inverta Finance Limited | Professional & scientific | 2015 |