| IH Cars Ltd | Wholesale & retail | 2024 |
| Ijaz Properties Investments Ltd | Real estate | 2023 |
| IJT General Enterprise Limited | Hospitality | 2022 |
| IK Goldsmith Ltd | Other services | 2024 |
| Ikigai Apparel Ltd | Wholesale & retail | 2024 |
| Ikore Limited | Information & communication | 2015 |
| Ilili London Limited | Hospitality | 2022 |
| ILP Services 24/7 Ltd | Other services | 2022 |
| Imobile and Services Ltd | Wholesale & retail | 2018 |
| Imogenesys Limited | Professional & scientific | 2008 |
| Imperial Car Services Ltd | Administrative & support | 2019 |
| Imperial Consultants & Trainers Limited | Education | 2011 |
| Imperial Healthcare Consultancy Limited | Wholesale & retail | 2020 |
| Imperial Solicitors Ltd | Professional & scientific | 2018 |
| Imperium Gleam Ltd | Administrative & support | 2025 |
| IMR Property Investment Ltd | Households | 2024 |
| Inbox Renovations Ltd | Real estate | 2024 |
| Inclusive World Travel Ltd | Administrative & support | 2023 |
| Index MED Ltd | Information & communication | 2026 |
| Indian Buffet Restaurant Ltd | Hospitality | 2019 |
| Indigo Family Ltd | Professional & scientific | 2022 |
| Indigo Living Ltd | Real estate | 2024 |
| Ineo Intelligence Ltd | Real estate | 2017 |
| Infinity Mayfair Ltd | Hospitality | 2018 |
| Infinityredox Holdings Limited | Manufacturing | 2018 |
| Infisure Investments Limited | Real estate | 2017 |
| Infobridge Global Limited | Information & communication | 2014 |
| Infomate Tech Ltd | Information & communication | 2020 |
| INIA-5 UK Ltd | Professional & scientific | 2014 |
| Inkonvenience Limited | Wholesale & retail | 2026 |
| Inma Gulf Trading Company Limited | Wholesale & retail | 2026 |
| Inner Strength Studio Ltd | Arts & recreation | 2024 |
| Innosync Services Ltd | Information & communication | 2013 |
| Inshaa Decoration Limited | Construction | 2024 |
| Inside Advantage Limited | Professional & scientific | 2015 |
| Inside Impact Ltd | Professional & scientific | 2022 |
| Insideout Property Group Ltd | Real estate | 2026 |
| Insightsys Ltd | Information & communication | 2025 |
| Insoftyx Ltd | Wholesale & retail | 2024 |
| Inspired Renovations Ltd | Manufacturing | 2024 |
| Inspirited Design Ltd | Information & communication | 2023 |
| Instagrab Pretzel Limited | Manufacturing | 2018 |
| Integrated Learning Academy Ltd | Education | 2020 |
| Intel-Struct Concepts Ltd | Construction | 2026 |
| Intellicious Ltd | Wholesale & retail | 2025 |
| Interactable Ltd | Manufacturing | 2018 |
| Interlink Business Solutions Limited | Professional & scientific | 2014 |
| International Academy of London Ltd | Education | 2013 |
| International Patients Ltd | Information & communication | 2026 |
| International Patients Services Limited | Information & communication | 2010 |
| International Techno Co Ltd. | Construction | 2022 |
| Interpoint Car Limited | Transport & logistics | 2019 |
| Inverex.Uk Limited | Wholesale & retail | 2024 |
| Investico Limited | Real estate | 2019 |
| Investigate the Unknown Ltd | Professional & scientific | 2020 |
| Investinukproperty Ltd | Real estate | 2025 |
| Investors Elite Network Limited | Administrative & support | 2022 |
| Invictus Security and Recruitment Services Ltd | Administrative & support | 2022 |
| IPR Skin Care Aesthetics Clinic Limited | Other services | 2023 |
| Iproduct Consulting Limited | Information & communication | 2025 |
| IQA Trading Ltd | Transport & logistics | 2016 |
| IQB Trading Limited | Transport & logistics | 2023 |
| Iqra Food London Ltd | Hospitality | 2024 |
| Iran Zamin Restaurant UK Ltd | Hospitality | 2025 |
| Iristranscom Ltd | Extraterritorial | 2016 |
| Irobot Systems Ltd | Professional & scientific | 2021 |
| Ironmongery Giant Ltd | Construction | 1999 |
| Iscotech Ltd | Manufacturing | 2008 |
| Isha London Ltd | Wholesale & retail | 2025 |
| Ishan Services London Ltd | Transport & logistics | 2024 |
| Ishaq & Sons Ltd | Wholesale & retail | 2026 |
| Iska Group Ltd | Administrative & support | 2024 |
| Isquare Tech Solutions Ltd | Information & communication | 2022 |
| Istylemedia Ltd | Wholesale & retail | 2018 |
| IT & Smarthand Service Limited | Information & communication | 2023 |
| IT Solutions Support Ltd | Other services | 2019 |
| ITA Property Investment Ltd | Real estate | 2021 |
| Itea 21 Ltd | Information & communication | 2018 |
| ITS Organic PVT Ltd | Wholesale & retail | 2024 |
| Itsgivinghurr Ltd | Other services | 2024 |
| Izabella Southgate Ltd | Hospitality | 2025 |
| Izahang Ltd | Health & social care | 2014 |
| J & I Medics Ltd | Financial services | 2019 |
| J & L Accountancy Ltd | Professional & scientific | 2010 |
| J & S Sandhu UK Ltd | Wholesale & retail | 2020 |
| J C GAS & Heating Limited | Construction | 2017 |
| J Edwards Property Investment Ltd | Real estate | 2019 |
| J Garry Services Limited | Construction | 2003 |
| J Greaney Ltd | Wholesale & retail | 2017 |
| J K a Blessed & Favoured Limited | Health & social care | 2015 |
| J K Motors ( London ) Limited | Wholesale & retail | 2012 |
| J Point Ltd | Hospitality | 2021 |
| J Remedial & Installation Ltd | Construction | 2025 |
| J Whyte Properties Ltd | Real estate | 2017 |
| J.Donno Dental Laboratory Limited | Health & social care | 2015 |
| J.Preedy Solicitors Ltd | Professional & scientific | 2021 |
| J8 Consulting Ltd | Professional & scientific | 2025 |
| Jacaranda Gardening Services Limited | Administrative & support | 2016 |
| Jade Sterling Limited | Construction | 2023 |
| Jaffe Holdings Ltd | Financial services | 2020 |