| Imperium Intellectus Limited | Real estate | 2025 |
| Imperium Vehicle Management Ltd | Other services | 2025 |
| Implicit Impression Ltd | Professional & scientific | 2024 |
| Impo International Limited | Wholesale & retail | 2016 |
| Improve (Properties) Limited | Real estate | 2017 |
| Improve Residential Limited | Real estate | 2023 |
| Improve Your Smile Ltd | Health & social care | 2010 |
| Impulse Consultancy Services Limited | Information & communication | 2016 |
| Imran Property Group Ltd | Real estate | 2022 |
| Imran Sheikh Limited | Health & social care | 2014 |
| Imran Superstore Ltd | Wholesale & retail | 2023 |
| Ims-Smart Limited | Information & communication | 2008 |
| IN Bloom Consulting Limited | Information & communication | 2016 |
| IN Good Spirits Ltd | Hospitality | 2026 |
| IN Good Time Limited | Administrative & support | 2013 |
| IN Grid Visual Media Limited | Information & communication | 2006 |
| IN House Inventories Ltd. | Administrative & support | 2000 |
| IN the Detail Bookkeeping Limited | Professional & scientific | 2023 |
| IN Your Dreams Limited | Wholesale & retail | 2015 |
| In-Uk Tech Ltd | Information & communication | 2024 |
| IN2IT Electrical Services Ltd | Construction | 2020 |
| Inayat & Bros Ltd | Information & communication | 2025 |
| Inbri Mart Limited | Wholesale & retail | 2025 |
| Inca Tech Services Ltd | Information & communication | 2021 |
| Incentive Gifts Limited | Extraterritorial | 1985 |
| Incfy Services Ltd | Professional & scientific | 2021 |
| Inchquest Limited | Extraterritorial | 2005 |
| Inclusive Care Support - Leaving Care Services Ltd | Health & social care | 2022 |
| Inclusive Care Support Limited | Health & social care | 2009 |
| Inclusive Children Services Ltd | Health & social care | 2023 |
| Inclusive IT Ltd | Education | 2016 |
| Inco Holdings Ltd. | Real estate | 2018 |
| Incomparable Business Solutions Limited | Professional & scientific | 2016 |
| Incos Limited | Manufacturing | 1998 |
| Incredible Tours Limited | Administrative & support | 2016 |
| Incrystals Limited | Wholesale & retail | 2006 |
| IND Tech Kenton Limited | Financial services | 2011 |
| Inde Artisans Limited | Wholesale & retail | 2023 |
| Independent Diplomat | Administrative & support | 2005 |
| Independent Lenses Ltd | Professional & scientific | 2024 |
| Independent Lifestyle Care Ltd | Health & social care | 2011 |
| Independent Pet Care Ltd | Professional & scientific | 2024 |
| Independent Trust and Finance Limited | Financial services | 1967 |
| Independent Vegan Food Ltd | Wholesale & retail | 2022 |
| Index Paediatrics Limited | Information & communication | 2013 |
| Indhith UK Ltd | Wholesale & retail | 2025 |
| Indian Brother Enterprise Ltd | Transport & logistics | 2025 |
| Indian Culinary Diaspora Limited | Other services | 2026 |
| Indian Curry Kitchen Ltd | Hospitality | 2020 |
| Indian Dhaba Limited | Hospitality | 2024 |
| Indian Midas Limited | Wholesale & retail | 2018 |
| Indian Ocean (Bournemouth) Ltd | Hospitality | 2005 |
| Indian Ocean (Modern) Limited | Hospitality | 2010 |
| Indian Ocean Westcliff Trading Limited | Hospitality | 2013 |
| Indian Passport Agents Ltd | Professional & scientific | 2022 |
| Indian Signature Food Ltd | Hospitality | 2026 |
| Indian Store Mart Ltd | Wholesale & retail | 2024 |
| Indian Tech SOC Limited | Information & communication | 2025 |
| Indian Vegetable Limited | Wholesale & retail | 2023 |
| Indian Visa Agents Ltd | Professional & scientific | 2022 |
| Indians at UK | Information & communication | 2020 |
| Indigenous Consultants Limited | Professional & scientific | 2024 |
| Indigo 7 Limited | Information & communication | 1995 |
| Indigo Ignite Ltd | Professional & scientific | 2012 |
| Indigo LLC Limited | Arts & recreation | 2023 |
| Indigo Supported Living Ltd | Health & social care | 2018 |
| Indigostone UK Ltd | Wholesale & retail | 2015 |
| Individual Minds Ltd | Education | 2026 |
| Indo Ceylon Services Limited | Wholesale & retail | 2023 |
| Indoco Remedies UK Limited | Manufacturing | 2022 |
| Indou Limited | Manufacturing | 2001 |
| Indra Tutors Ltd | Education | 2023 |
| Indradhanush Motion Pictures Limited | Information & communication | 2023 |
| Indtl App Ltd | Professional & scientific | 2020 |
| Indulge ME Limited | Wholesale & retail | 2010 |
| Indura Limited | Professional & scientific | 2022 |
| Indus Property Limited | Real estate | 2018 |
| Indus Supplies Ltd | Wholesale & retail | 2026 |
| Indus Tours & Travel Limited | Administrative & support | 1995 |
| Industrial & Commercial Agencies Limited | Administrative & support | 1996 |
| Industrial Chemical Enterprise Limited | Other services | 2013 |
| Industrial Overload Limited | Administrative & support | 1985 |
| Inetd Limited | Information & communication | 2017 |
| Infill Garlick Hill Ltd | Real estate | 2025 |
| Infinea Limited | Information & communication | 2015 |
| Infinite Capital Limited | Real estate | 2018 |
| Infinite Contract Solutions Ltd | Professional & scientific | 2009 |
| Infinite Market Ltd | Wholesale & retail | 2023 |
| Infinite Medical Limited | Health & social care | 2014 |
| Infinite Number Limited | Information & communication | 2025 |
| Infiniteexim Ltd | Wholesale & retail | 2026 |
| Infinity Advisory and Management Limited | Professional & scientific | 2015 |
| Infinity and Beyond Care EBD Homes Ltd | Health & social care | 2023 |
| Infinity Assets Management Limited | Real estate | 2022 |
| Infinity FSG Ltd | Wholesale & retail | 2008 |
| Infinity Homecare Services Ltd | Health & social care | 2026 |
| Infinity LFP Limited | Wholesale & retail | 2016 |
| Infinity Mindz for Business Ltd | Professional & scientific | 2025 |
| Infinity Mindz Ltd | Professional & scientific | 2023 |
| Infinity Property Solutions Limited | Real estate | 2007 |