| I-Kitchen UK Ltd | Manufacturing | 2018 |
| I-Lyka Fit Ltd | Wholesale & retail | 2023 |
| I-Search Services Limited | Financial services | 2007 |
| I-Sure Consulting Ltd | Information & communication | 2021 |
| I. Khokhar Ltd | Health & social care | 2010 |
| I.& I.Craven & Co.,Limited | | 1923 |
| I.A Auto Repairs Ltd | Wholesale & retail | 2016 |
| I.A.Z Facilities Management Services Ltd | Transport & logistics | 2019 |
| I.Alam Solutions Limited | Administrative & support | 2018 |
| I.K.D. ACC Ltd | Professional & scientific | 2018 |
| I.Khan Pharm Ltd | Wholesale & retail | 2023 |
| I.S. Master Limited | Health & social care | 2021 |
| I.T.I. Holdings Limited | Real estate | 2019 |
| I.T.S. Turbo Chargers Ltd | Professional & scientific | 2011 |
| I2YOU Ltd | Wholesale & retail | 2025 |
| I3 Technology Group Limited | Wholesale & retail | 2017 |
| I3MOBILE Ltd | Information & communication | 2019 |
| I6 Holdings Limited | Real estate | 2023 |
| IA Consultancy Limited | Professional & scientific | 2018 |
| IA Electrical Contractors Ltd | Construction | 2025 |
| IA IYI Ltd | Financial services | 2023 |
| IA London Limited | Financial services | 2025 |
| IA Optical Ltd | Health & social care | 2021 |
| IA Properties Yorkshire Limited | Real estate | 2026 |
| IA RAD Ltd Limited | Health & social care | 2020 |
| IA Travel Hub Ltd | Administrative & support | 2025 |
| Iaau Accountants Ltd | Professional & scientific | 2020 |
| Iabouquet Ltd | Wholesale & retail | 2024 |
| Iaccend Initiative CIC | Administrative & support | 2026 |
| Iacg Ltd | Transport & logistics | 2024 |
| IAD Services Ltd | Professional & scientific | 2023 |
| IAG Mechanical Ltd | Construction | 2023 |
| IAH Commerce Ltd | Wholesale & retail | 2026 |
| IAH Limited | Professional & scientific | 2016 |
| IAH Logistics Ltd | Transport & logistics | 2022 |
| IAI Store Limited | Wholesale & retail | 2025 |
| IAI24 Ltd | Wholesale & retail | 2024 |
| IAM Logistics Ltd | Transport & logistics | 2023 |
| IAN Investments Ltd | Financial services | 2026 |
| IAN Thornton Business Services Ltd | Financial services | 2026 |
| Iara Technology Limited | Information & communication | 2024 |
| Iawan Consultancy Ltd | Professional & scientific | 2026 |
| IB Auto Services Ltd | Wholesale & retail | 2024 |
| IB Homes Investments Ltd | Real estate | 2026 |
| IB212 Central European Developments Ltd | Construction | 2025 |
| IBA Brothers Ltd | Hospitality | 2021 |
| IBA Bureau Limited | Administrative & support | 2016 |
| IBA Business Services Limited | Professional & scientific | 2004 |
| IBA Consulting Yorkshire Ltd | Professional & scientific | 2023 |
| IBA Holdings Yorkshire Ltd | Financial services | 2023 |
| Iball Optics Limited | Administrative & support | 2015 |
| Ibby BD Ltd | Transport & logistics | 2026 |
| Ibby Logistics Ltd | Transport & logistics | 2025 |
| Ibbys Couriers Limited | Transport & logistics | 2025 |
| Ibeq Limited | Education | 2025 |
| Ibex Mart UK Ltd | Wholesale & retail | 2025 |
| IBI Healthcare Ltd | Wholesale & retail | 2010 |
| IBI Yorkshire Limited | Education | 2019 |
| Ibis-Cables Ltd | Wholesale & retail | 2023 |
| Ibraheem Transport Ltd | Transport & logistics | 2025 |
| Ibtt Properties Ltd | Real estate | 2018 |
| Ibula Properties Ltd | Real estate | 2025 |
| IBY Khan Consultancy Ltd | Professional & scientific | 2023 |
| IBY Khan Solicitors Ltd | Professional & scientific | 2025 |
| Ibys Diner Ltd | Hospitality | 2018 |
| Ibytech Ltd | Information & communication | 2025 |
| Ibzu Ltd | Transport & logistics | 2026 |
| IC Electrical (SY) Limited | Construction | 2018 |
| Icarcash Ltd | Wholesale & retail | 2019 |
| Ice Candy Desserts Limited | Hospitality | 2019 |
| Ice City Desserts 2 Ltd | Hospitality | 2023 |
| Ice Cream Palace Limited | Hospitality | 2019 |
| Ice Stone Jesmond Limited | Hospitality | 2018 |
| Ice Time C.I.C. | Arts & recreation | 1996 |
| Iceburg Bradford Ltd | Hospitality | 2025 |
| Iceego Ltd | Wholesale & retail | 2021 |
| Icestone Franchising Limited | Hospitality | 2016 |
| Icestone Supplies Limited | Administrative & support | 2014 |
| ICF Engineering Limited | | 1982 |
| Ichicoo Limited | Wholesale & retail | 2007 |
| Iconic Developments (London) Limited | Real estate | 2021 |
| Icorrect Limited | Wholesale & retail | 2012 |
| Icreate Interiors Limited | Manufacturing | 2023 |
| ICS UK (1976) Limited | Financial services | 2021 |
| Icskyshape Ltd | Professional & scientific | 2024 |
| Icyy Ltd | Manufacturing | 2024 |
| ID Coachwork Specialists Ltd | Wholesale & retail | 2018 |
| ID Installations (UK) Limited | Construction | 2013 |
| Idan Property Ltd | Real estate | 2023 |
| Ideal Design & Construction Services Ltd | Construction | 2017 |
| Ideal Flights Ltd | Administrative & support | 2014 |
| Ideal Jewellery Ltd | Wholesale & retail | 2015 |
| Ideaz-Uk Ltd | Extraterritorial | 2014 |
| Idle High Street Properties Limited | Real estate | 2013 |
| Idle Lounge Coffee House Limited | Hospitality | 2017 |
| Idle Motors Ltd | Wholesale & retail | 2023 |
| Idle Pizza & Curry House Ltd | Hospitality | 2024 |
| Idle Road Carpets Ltd | Wholesale & retail | 2025 |
| Idle Road OFF Licence Ltd | Wholesale & retail | 2025 |
| Idle Sandwich Company Limited | Hospitality | 2026 |