| Ibanm Ltd | Construction | 2020 |
| Iberoptima UK Limited | Other services | 2019 |
| Ibes Drylining UK Ltd | Construction | 2020 |
| Ibos Couriers Limited | Transport & logistics | 2015 |
| Ibuyanycars Ltd | Wholesale & retail | 2023 |
| IC Financial Services UK Limited | Professional & scientific | 2012 |
| ICD London Solutions Ltd | Construction | 2012 |
| Iceni Dental Limited | Health & social care | 2023 |
| ICF Building Ltd | Construction | 2021 |
| ICF Supplies Limited | Other services | 2012 |
| Icfs Design and Build Limited | Construction | 2017 |
| ICH22 Ltd | Real estate | 2022 |
| Iconic Commercial Investment Group Limited | Real estate | 2023 |
| Iconic Heating Ltd | Construction | 2019 |
| Iconique International Limited | Other services | 2023 |
| Iconsulting Company London Limited | Professional & scientific | 2025 |
| Icontowers Media Ltd | Information & communication | 2020 |
| Icool Air Conditioning Limited | Energy | 2023 |
| ID Engines Limited | Wholesale & retail | 2022 |
| Ideal Reprographics Eastern Limited | Information & communication | 1980 |
| IDH Consultants UK Associates Ltd | Professional & scientific | 2012 |
| IDK (U.K) Limited | Other services | 2021 |
| Idleserv Ltd | Information & communication | 2007 |
| IDM Construction Limited | Construction | 2018 |
| IFE Global Digital Logistics Limited | Extraterritorial | 2023 |
| IFE Global Logistics (Road Freight) Limited | Transport & logistics | 2023 |
| Ifnakk Ltd | Construction | 2021 |
| Ifocus Capital Ltd | Administrative & support | 2019 |
| IG Corporate Training & Consultancy Ltd | Professional & scientific | 2017 |
| IGN Catering Ltd | Hospitality | 2023 |
| Ignis Fire Limited | Public administration | 2017 |
| Ignite Insurance Brokers Limited | Financial services | 2018 |
| Ignite-It Consulting Ltd | Information & communication | 2019 |
| Igrci Limited | Professional & scientific | 2017 |
| Ihhl Ltd | Real estate | 2021 |
| Ij's Europe Food & Drink Ltd | Hospitality | 2013 |
| IK & E Global Ltd | Wholesale & retail | 2024 |
| Ilaser and Skin Clinic Ltd | Other services | 2023 |
| Ileks Transport Ltd | Transport & logistics | 2018 |
| Ilki Keystones Partners Ltd | Administrative & support | 2025 |
| IM Agri-Tech Solutions Limited | Manufacturing | 2022 |
| IM Automation Systems Limited | Manufacturing | 2004 |
| Images in Frames (Wanstead) Limited | Wholesale & retail | 2011 |
| Images in Frames Ltd | Wholesale & retail | 2003 |
| Imagine Design & Build Ltd | Professional & scientific | 2019 |
| Imas Holdings Limited | Financial services | 2023 |
| Imas Investments Limited | Real estate | 2016 |
| Imaxx Limited | Manufacturing | 2019 |
| Imddg Ltd | Construction | 2021 |
| Immaculate Improvements Ltd | Construction | 2020 |
| Immaculate Software Solutions Ltd | Information & communication | 2021 |
| Immervox Limited | Information & communication | 1999 |
| Impact Essex Ltd | Construction | 2022 |
| Impact Healthcare Services Ltd | Public administration | 2018 |
| Impact Logistics Ltd | Transport & logistics | 2017 |
| Impek Ltd | Information & communication | 2019 |
| Imperial Asset Management Global Ltd | Financial services | 2024 |
| Imperial Ceramics Limited | Construction | 2015 |
| Imperial Glass Tech Ltd | Construction | 2025 |
| Imperial Heating Services Ltd | Administrative & support | 2013 |
| Imperium Estate Group Ltd | Construction | 2025 |
| Imperium Services Ltd | Professional & scientific | 2022 |
| Imperium Servitia Ltd | Administrative & support | 2025 |
| Impetors Ltd | Information & communication | 2015 |
| Impex PK Ltd | Wholesale & retail | 2020 |
| Impi Capital Ltd | Financial services | 2019 |
| Impi Properties Limited | Real estate | 2016 |
| Impressions Reactive Ltd | Construction | 2017 |
| IMV Logistics Ltd | Extraterritorial | 2021 |
| IN Control Projects & Service Ltd | Professional & scientific | 2018 |
| IN Control Projects Limited | Wholesale & retail | 2003 |
| IN Control Service Limited | Wholesale & retail | 2016 |
| IN Depth Mental Health Ltd | Health & social care | 2018 |
| IN Your Corner Coaching Limited | Professional & scientific | 2025 |
| Indbrit Traders Ltd | Wholesale & retail | 2025 |
| Independent Nest Support Babies and Mom's Unit Limited | Health & social care | 2021 |
| Independent Procurement Services Limited | Information & communication | 2003 |
| India & International Law Consultants Limited | Administrative & support | 2015 |
| Indian Spice Delight Ltd | Hospitality | 2023 |
| Indig Ltd | Transport & logistics | 2017 |
| Indigo Facilities Ltd | Construction | 2023 |
| Industrial Kitchen Solutions Limited | Construction | 2011 |
| Industrial Plant Hire Limited | Administrative & support | 2019 |
| Industrial Plant Services (UK) Limited | Manufacturing | 2005 |
| Industrial Staffing Solutions Limited | Administrative & support | 1996 |
| Industry Hairdressing & Barbering Ltd | Other services | 2019 |
| INE Construction Ltd | Construction | 2017 |
| Infinita Group Ltd | Financial services | 2018 |
| Infinite Detail Autocare Ltd. | Wholesale & retail | 2017 |
| Infinity Central Ltd | Administrative & support | 2025 |
| Infinity DJ Music Ltd | Information & communication | 2025 |
| Infinity Home and Paving Ltd | Construction | 2019 |
| Infinity Rise Solutions Ltd | Information & communication | 2024 |
| Infinity Security Systems Ltd | Administrative & support | 2013 |
| INFINITY360 Ltd | Wholesale & retail | 2026 |
| Info Accounting Ltd | Professional & scientific | 2019 |
| Inforflow Limited | Information & communication | 2014 |
| Infotrace Limited | Administrative & support | 2019 |
| Inglis Badrashi Limited | Professional & scientific | 2000 |
| Inglis Forktruck Services Ltd | Manufacturing | 2021 |