| Imphal Consulting Ltd | Professional & scientific | 2011 |
| Impicci & Imbrogli Ltd | Hospitality | 2022 |
| Impression Moulds Limited | Manufacturing | 1996 |
| Imran Yusuf EYE Surgery Limited | Professional & scientific | 2020 |
| IN and Under One Roof Limited | Information & communication | 2019 |
| IN Focus Services Limited | Administrative & support | 2019 |
| IN This Together Bucks CIC | Health & social care | 2024 |
| IN Time Consultancy Limited | Professional & scientific | 2020 |
| Inbyld Property Ltd | Real estate | 2026 |
| Incahome Ltd | Arts & recreation | 2013 |
| Incredible ME Education Ltd | Education | 2020 |
| Indecently Bound Books Ltd | Wholesale & retail | 2026 |
| Independent Carestaff Ltd | Health & social care | 2024 |
| Independent Finance Directors Limited | Professional & scientific | 2000 |
| Independent Gymnastics Affiliation Limited | Education | 2017 |
| Independent Gymnastics Limited | Arts & recreation | 2000 |
| Independent Substation Services Limited | Other services | 2011 |
| Indika Sounds Ltd | Administrative & support | 2026 |
| Inedit Solution Ltd | Construction | 2013 |
| Inext Services Limited | Construction | 2020 |
| Infallible Technologies Ltd | Information & communication | 2024 |
| Infanite Properties Ltd | Administrative & support | 2019 |
| Infinite Loom Limited | Manufacturing | 2020 |
| Infinity Building and Renovations Limited | Construction | 2009 |
| Infinity Business Consultancy Limited | Information & communication | 2021 |
| Infinity Business Ventures Limited | Professional & scientific | 2020 |
| Infinity Carpentry - Joinery Ltd | Construction | 2021 |
| Infinity Entities Limited | Professional & scientific | 2021 |
| Infinity FL Group Ltd | Construction | 2025 |
| Infinity Hotels Limited | Financial services | 2018 |
| Infinity K9 Ltd | Other services | 2021 |
| Infinity Products Trading Limited | Wholesale & retail | 2023 |
| Infinity Success Ltd | Transport & logistics | 2021 |
| Infinityride Ltd | Transport & logistics | 2024 |
| Influencer Hospitality Limited | Financial services | 2025 |
| Infocus Data to Insights Ltd | Professional & scientific | 2023 |
| Inform Pharma Consulting Ltd | Administrative & support | 2008 |
| Informed Life Decisions Ltd | Other services | 2023 |
| Informing Limited | Arts & recreation | 2006 |
| Infortecorp Solutions Limited | Information & communication | 2013 |
| Infotech for Consultation and Services Ltd | Information & communication | 2020 |
| Infraarc Solutions Limited | Information & communication | 2019 |
| Ingen Property Solutions Ltd. | Construction | 2023 |
| Ingenium Limited | Information & communication | 1998 |
| Ingenium MEP Ltd | Professional & scientific | 2024 |
| Inglebrook Limited | Real estate | 2001 |
| Inglesham Consulting Limited | Administrative & support | 2015 |
| Ingram Family Builders Limited | Construction | 2011 |
| INI Motors Ltd | Wholesale & retail | 2015 |
| Initec Limited | Information & communication | 2017 |
| Initial Ideas Advertising Limited | Professional & scientific | 2001 |
| INK & Bloom Ltd | Wholesale & retail | 2025 |
| INK & Glow Ltd | Wholesale & retail | 2025 |
| INK Revoir Limited | Other services | 2025 |
| Inkanyezi Ltd | Health & social care | 2022 |
| Inkify Limited | Wholesale & retail | 2020 |
| Inlight Electrical Aylesbury Ltd | Construction | 2022 |
| Inlight Electrical Services Ltd | Construction | 2019 |
| Inlight Holding Ltd | Construction | 2023 |
| Innate Vitality | Health & social care | 2008 |
| Innes Eaton Electrical Services Ltd | Construction | 2022 |
| Inno-Bi Services Ltd | Information & communication | 2011 |
| Innoflex Systems Limited | Information & communication | 1996 |
| Innosys Technologies Ltd | Information & communication | 2026 |
| Innovation Creator Network Limited | Other services | 2024 |
| Innovative Deals Ltd | Wholesale & retail | 2020 |
| Innovative Start Limited | Health & social care | 2017 |
| Innovative Web Solutions Ltd | Information & communication | 2018 |
| Innovus Properties Limited | Real estate | 2023 |
| Inoutin Limited | Real estate | 2025 |
| Insearch Consulting Limited | Wholesale & retail | 2015 |
| Insentra (AY) Limited | Administrative & support | 2008 |
| Insight 63 Ltd | Administrative & support | 2014 |
| Insight Bible Church Limited | Health & social care | 2021 |
| Insight Care & Support Ltd | Health & social care | 2022 |
| Insignis Academy Trust | Education | 2011 |
| Inspire Carpentry Ltd | Manufacturing | 2022 |
| Inspire Global Mobility Consulting Limited | Professional & scientific | 2021 |
| Inspire Property Holdings Ltd | Real estate | 2024 |
| Inspired Complete Services Domestics Ltd | Administrative & support | 2023 |
| Inspired Complete Services Limited | Households | 2017 |
| Inspired Complete Services Maintenance Ltd | Construction | 2023 |
| Inspired Complete Services Professional Ltd | Administrative & support | 2023 |
| Inspired Khaya Limited | Professional & scientific | 2015 |
| Installation & Design Services Limited | Extraterritorial | 1999 |
| Instant Delights Ltd | Hospitality | 2011 |
| Instant Hedges Limited | Extraterritorial | 2012 |
| Intalbury Management Ltd | Real estate | 2014 |
| Integricom Ltd | Information & communication | 2006 |
| Intelligiants Ltd. | Information & communication | 2014 |
| Intelliglobe Solutions Ltd | Information & communication | 2024 |
| Intelliwave Analytics Limited | Professional & scientific | 2025 |
| Intentio Consulting Limited | Information & communication | 2025 |
| Intentional Parenting UK CIC | Information & communication | 2025 |
| Inter City Cleaning Services Limited | Administrative & support | 1987 |
| Inter City Holdings Limited | Financial services | 2015 |
| Interact Digital Ltd | Information & communication | 2013 |
| Interact Finance Ltd. | Financial services | 2015 |
| Interact Software Limited | Information & communication | 1975 |
| Interactive Components Limited | Wholesale & retail | 2012 |