| ICT GL Limited | Construction | 2022 |
| Idaramax Limited | Transport & logistics | 2019 |
| IDC Transports Limited | Transport & logistics | 2017 |
| Ideal Auto Trade Ltd | Wholesale & retail | 2022 |
| IDF Optic Ltd | Construction | 2023 |
| IDL Comms Limited | Information & communication | 2012 |
| IDM London Investments Limited | Real estate | 2018 |
| IDM Trans Ltd | Transport & logistics | 2016 |
| Idris Hamzat Limited | Manufacturing | 2020 |
| Ifixedlondon Ltd | Construction | 2026 |
| IGA Services Limited | Construction | 2018 |
| IGA Trans Ltd | Transport & logistics | 2019 |
| IGE Electrical Limited | Construction | 2012 |
| IGE Installations Limited | Administrative & support | 2010 |
| Ihsaan Investments Group Limited | Financial services | 2026 |
| Iicreate 3 Sixty UK Ltd | Administrative & support | 2025 |
| Ijalo Systems Ltd | Information & communication | 2026 |
| IJM Electrical Services Limited | Construction | 2017 |
| IJS Trans Ltd | Transport & logistics | 2025 |
| IJT Electrical Services Ltd | Construction | 2020 |
| Ilearani Ltd | Information & communication | 2025 |
| Ilirian Construction Ltd | Construction | 2017 |
| Imaks Global Limited | Real estate | 2015 |
| Imbryk Ltd | Wholesale & retail | 2024 |
| Imdirectontime Ltd | Transport & logistics | 2021 |
| Imeh Ltd | Transport & logistics | 2026 |
| Imitariapparel Ltd | Wholesale & retail | 2025 |
| Immi & Arsal Ltd | Wholesale & retail | 2024 |
| Imperial Surfacing Ltd | Construction | 2018 |
| Impress Design & Build Ltd | Construction | 2025 |
| IN Purpose Ltd | Professional & scientific | 2019 |
| In-Stone (Contracts) Limited | Professional & scientific | 2010 |
| In-Touch Business Solutions Ltd | Professional & scientific | 2013 |
| Inabis Ltd | Transport & logistics | 2019 |
| Incline ESC Ltd | Professional & scientific | 2025 |
| Inclusive Social Welfare and Empowerment Ltd | Health & social care | 2020 |
| Incrowd Ltd | Construction | 2022 |
| IND Deals Limited | Wholesale & retail | 2025 |
| Independent Alarms Ltd | Administrative & support | 2014 |
| Independent Homes Limited | Administrative & support | 2010 |
| Index Capital Limited | Construction | 2012 |
| Indian Spice Takeaway Ltd | Hospitality | 2018 |
| Indiana Kitchen Limited | Hospitality | 2023 |
| Indimax Ltd | Wholesale & retail | 2018 |
| Indre Finance Ltd | Administrative & support | 2023 |
| Indus Valley Textiles Ltd | Real estate | 2022 |
| Inesas Art Ltd | Arts & recreation | 2024 |
| Infiniity 3 Contracts Limited | Administrative & support | 2013 |
| Infiniity 3 Limited | Professional & scientific | 2012 |
| Infinity Power Solutions Limited | Construction | 2011 |
| Infoprints Limited | Wholesale & retail | 2022 |
| Infosys Consultancy Ltd | Information & communication | 2013 |
| Infozar Solutions Limited | Information & communication | 2024 |
| Infra Services Ltd | Professional & scientific | 2019 |
| Inheir Ltd | Real estate | 2025 |
| INK by Perry Ltd | Arts & recreation | 2018 |
| Inkk Steel and Digital Ltd | Administrative & support | 2018 |
| Inkk Steel Services Ltd | Construction | 2017 |
| Inline Boxing Ltd | Arts & recreation | 2024 |
| Inline Film Ltd | Information & communication | 2019 |
| Inner Health Collective Ltd | Health & social care | 2020 |
| Inner Wealth Coaching Ltd | Wholesale & retail | 2026 |
| Innexus Limited | Professional & scientific | 2020 |
| Innotax Ltd | Professional & scientific | 2025 |
| Innox Petroleum Trading Company Ltd | Mining & quarrying | 2025 |
| Insight Nexa Limited | Information & communication | 2025 |
| Insight Optica Ltd | Health & social care | 2023 |
| Insight Transformation Group Limited | Information & communication | 2026 |
| Insightng Projects Limited | Administrative & support | 2011 |
| Insignia Asset Management Ltd | Professional & scientific | 2022 |
| Insignia Logistics Ltd | Wholesale & retail | 2021 |
| Insignia Shipping Services Ltd | Transport & logistics | 2013 |
| Inspira Energy Ltd | Health & social care | 2025 |
| Instajobber Ltd | Information & communication | 2018 |
| Install Pro Solutions Ltd | Construction | 2025 |
| Instant Service Providers Limited | Information & communication | 2025 |
| Instaprinting Limited | Administrative & support | 2022 |
| Insync Medical Ltd | Health & social care | 2010 |
| Inta Contracts Group Ltd | Construction | 2024 |
| Integrated Multimedia Limited | Information & communication | 2014 |
| Inteli Constructions Ltd | Manufacturing | 2019 |
| Intellitecservices Ltd | Information & communication | 2022 |
| Intercontinental Corporate Services Limited | Professional & scientific | 2007 |
| Interior by TAR Ltd | Professional & scientific | 2024 |
| Interior Property Solutions Limited | Construction | 2009 |
| International Capital Investment House Ltd | Financial services | 2021 |
| International Corporation and Technical Services Ltd | Professional & scientific | 2026 |
| International Road Safety Training Limited | Administrative & support | 1994 |
| International Settlement Group Ltd | Professional & scientific | 2023 |
| International Tape Ball Cricket Board Ltd | Arts & recreation | 2025 |
| Interpretersportal Ltd | Information & communication | 2009 |
| Into the Pages Events Ltd | Wholesale & retail | 2023 |
| Intovention Ltd | Wholesale & retail | 2024 |
| Invent Construction Ltd | Construction | 2018 |
| Inventory Centric Ltd | Real estate | 2024 |
| Invest Haus Ltd | Real estate | 2024 |
| Invest in Yourself Youth Services Limited | Education | 2018 |
| Investar Consults Ltd | Professional & scientific | 2022 |
| Investify Holdings Group Ltd | Wholesale & retail | 2024 |
| Invision Security Ltd | Information & communication | 2012 |