| Iort Ltd | Administrative & support | 2024 |
| IOT Homes Limited | Construction | 2024 |
| Iota Projects Ltd | Construction | 2019 |
| IP Consultancy Partners Ltd | Professional & scientific | 2025 |
| Ipek Mobilya (Ilford) Ltd | Real estate | 2020 |
| IPL Laser & Beauty Clinic Ltd | Health & social care | 2010 |
| Ipswich Cafe Ltd | Hospitality | 2015 |
| Ipswich Valeting Centre Limited | Other services | 2009 |
| Iptp Ltd | Information & communication | 2007 |
| IPX Electrical Ltd | Extraterritorial | 2020 |
| IQ Accountancy Ltd | Professional & scientific | 1998 |
| IQ Estates Ltd | Real estate | 2018 |
| IQ Financial Accountants Limited | Professional & scientific | 2025 |
| IQ Financial Investments Ltd | Professional & scientific | 2026 |
| IQ Infosys Limited | Wholesale & retail | 2017 |
| IQ Partners Limited | Real estate | 2020 |
| Iqamah Collections Ltd | Wholesale & retail | 2024 |
| Iqbal Developments Ltd | Real estate | 2014 |
| Iqbal Tehnology Limited | Construction | 2025 |
| IQF International College Ltd | Education | 2019 |
| Iqra Naeem Ltd | Health & social care | 2021 |
| Iqraa Enterprises Ltd | Real estate | 2024 |
| IR Nexus Ltd | Wholesale & retail | 2026 |
| IRA Infotech Limited | Information & communication | 2022 |
| Irea Locums Ltd | Administrative & support | 2012 |
| Irecycle Waste Ltd | Water & waste | 2026 |
| Irena Cleaning Ltd | Water & waste | 2020 |
| IRG Pharma Ltd | Professional & scientific | 2025 |
| IRH Holdings Ltd | Real estate | 2026 |
| Irhan Enterprises Limited | Wholesale & retail | 2024 |
| Irimia Services Ltd | Construction | 2017 |
| Iris 200 Ltd | Real estate | 2025 |
| Iris EYE Care Limited | Wholesale & retail | 2024 |
| Iris Management Consultants Ltd | Wholesale & retail | 2012 |
| Irishi Distribution Limited | Professional & scientific | 2025 |
| Irmaan Limited | Wholesale & retail | 2014 |
| Irock Construction Limited | Construction | 2018 |
| Ironcrest Group Ltd | Construction | 2025 |
| IRS Partners Ltd | Professional & scientific | 2012 |
| IRS Software Ltd | Professional & scientific | 2025 |
| Iryo Services Limited | Health & social care | 2023 |
| Irys 1 Ltd | Real estate | 2023 |
| Irys 2 Ltd | Real estate | 2023 |
| Irys Global Ltd | Real estate | 2022 |
| Irysh Limited | Real estate | 2023 |
| IS Keys Ltd | Construction | 2021 |
| IS Oceans Ltd | Wholesale & retail | 2023 |
| IS Security Solutions Ltd | Financial services | 2024 |
| ISA Prestige Services Ltd | Transport & logistics | 2026 |
| ISA Private Limited | Wholesale & retail | 2025 |
| ISA Travels Ltd | Transport & logistics | 2021 |
| Isaacpharm Limited | Extraterritorial | 2010 |
| Isac's Cleaning Services Ltd | Administrative & support | 2020 |
| Isaf Ltd | Wholesale & retail | 2023 |
| Isamaya Automotive Ltd | Wholesale & retail | 2023 |
| Isetech Ltd. | Information & communication | 2017 |
| ISF Trading Enterprises Ltd | Wholesale & retail | 2025 |
| ISG Property Management Ltd | Households | 2023 |
| Isha Capital Ltd | Real estate | 2022 |
| Isha Suhag Ltd. | Arts & recreation | 2019 |
| Isham Singh Limited | Construction | 2024 |
| Ishaq Autos Ltd | Wholesale & retail | 2021 |
| Isher Properties Ltd | Construction | 2026 |
| Isher Transport & Logistics Limited | Wholesale & retail | 2020 |
| Ishu Ltd | Education | 2026 |
| Ishvaran Property Group UK Ltd | Real estate | 2025 |
| Isimplex Technologies Ltd | Other services | 2014 |
| ISJ Consultancy Limited | Information & communication | 2011 |
| ISK Investments Ltd | Real estate | 2025 |
| Iskynet Limited | Extraterritorial | 2019 |
| ISL Consulting Ltd | Professional & scientific | 2025 |
| Isla Dwellings Ltd | Real estate | 2026 |
| Islam Channel (Urdu) Ltd | Information & communication | 2005 |
| Islam Channel Bangla Ltd | Information & communication | 2022 |
| Islam Channel Limited | Information & communication | 2003 |
| Islam Steps Ltd | Information & communication | 2025 |
| Islamabad Halal Meat U.K Ltd | Wholesale & retail | 2018 |
| Islamabad Halal Meats Ilford Ltd | Wholesale & retail | 2024 |
| Islamabad Halal Meats Limited | Wholesale & retail | 2017 |
| Islamabad Ltd | Real estate | 2015 |
| Islamia Education Limited | Education | 2021 |
| Islamic Finance Solutions Limited | Financial services | 2024 |
| Island Brothers Caribbean Streetfood Ltd | Hospitality | 2025 |
| Island Burger Ltd | Hospitality | 2017 |
| Island Source Ltd | Wholesale & retail | 2026 |
| Island Style Catering Limited | Hospitality | 2021 |
| Islepride Limited | Real estate | 1991 |
| Ismah and Co Limited | Transport & logistics | 2020 |
| Ismail Creative Ltd | Manufacturing | 2019 |
| Ismail Erbil Limited | Wholesale & retail | 2026 |
| Isparkle Cleaning Ltd | Wholesale & retail | 2023 |
| Isql Ltd | Information & communication | 2015 |
| ISR Leadership Limited | Health & social care | 2024 |
| Israr Graphics Limited | Wholesale & retail | 2025 |
| Israsha Fuel and IT Limited | Energy | 2025 |
| Issa Property Limited | Real estate | 2025 |
| Istack Conferences Limited | Administrative & support | 2023 |
| Istaruk Limited | Wholesale & retail | 2017 |
| Istek Solutions Ltd | Information & communication | 2019 |
| Ists Properties Ltd | Real estate | 2020 |