| HWL 004 Limited | Real estate | 2020 |
| HWL Fleet Limited | Administrative & support | 2025 |
| Hydesbar Limited | Hospitality | 2016 |
| Hydra Home Renovations Ltd | Construction | 2024 |
| Hydro Heaven Ltd | Wholesale & retail | 2021 |
| Hydrographic Survey Consultants Ltd | Professional & scientific | 2017 |
| Hyena Security Ltd | Administrative & support | 2017 |
| Hyfitclub Ltd | Arts & recreation | 2025 |
| Hyperepm Consulting Limited | Information & communication | 2015 |
| Hypofix Ltd | Manufacturing | 2025 |
| Hypp Limited | Real estate | 2019 |
| I Chauffeuring Ltd | Transport & logistics | 2026 |
| I Consultancy NE Limited | Administrative & support | 2023 |
| I E S Instrumentation Electrical Services Limited | Construction | 2002 |
| I Johnston Consultancy Ltd | Manufacturing | 2025 |
| I K Electronics Limited | Real estate | 2003 |
| I O Payment Solutions Ltd | Professional & scientific | 2020 |
| I&Tel BIM Services Ltd | Professional & scientific | 2021 |
| I. C. Davison Limited | Construction | 2011 |
| I.L. Planning Ltd | Construction | 2017 |
| I.O.S Holdings Ltd | Wholesale & retail | 2022 |
| I.V Holdings Ltd | Real estate | 2024 |
| I2I Business Solutions Limited Liability Partnership | | 2002 |
| IAN D Vickers Building Services Limited | Construction | 2019 |
| IB Car Wash Limited | Administrative & support | 2024 |
| IB CMA Ltd | Other services | 2019 |
| IBA Homes&Lettings Ltd | Real estate | 2025 |
| Ibero Shop Latam Limited | Wholesale & retail | 2025 |
| Ibex Innovations Ltd | Manufacturing | 2010 |
| Ibrahim Ahmed Logistics Ltd | Transport & logistics | 2025 |
| Ibuild Home Improvements Ltd | Construction | 2018 |
| IC Automation Ltd. | Professional & scientific | 2016 |
| Icarus Services Limited | Professional & scientific | 2008 |
| ICC Services Ltd | Professional & scientific | 2024 |
| Iconvert Group Limited | Information & communication | 2024 |
| Ideal PA Ltd | Professional & scientific | 2022 |
| Idec Technical Products Limited | Professional & scientific | 2011 |
| Idris Building Limited | Construction | 2023 |
| IES Cable Ltd | Construction | 2001 |
| Ievolve CIC | Information & communication | 2025 |
| Ifem Co Global Ltd Ltd | Financial services | 2025 |
| Ifortek Consulting Ltd | Professional & scientific | 2023 |
| IFÉ Vision Capital Ltd | Construction | 2026 |
| IG Electrical Ltd | Professional & scientific | 2023 |
| IG Homes Ltd | Real estate | 2025 |
| Iget Ltd | Education | 2021 |
| IGG Group Ltd | Real estate | 2026 |
| IGH DD Limited | Information & communication | 2023 |
| Ignis Recruitment Limited | Administrative & support | 2019 |
| Ignite Community CIC | Health & social care | 2026 |
| Ignys Energy Ltd | Administrative & support | 2026 |
| IGO Construction Ltd | Construction | 2025 |
| Ihost Global Limited | Extraterritorial | 2016 |
| IIW Properties Limited | Financial services | 2025 |
| IJF Commercial Diving Ltd | Professional & scientific | 2024 |
| ILA Jointing & Cabling Services Ltd | Construction | 2023 |
| ILC Inspection Limited | Professional & scientific | 2013 |
| Ilex NE Ltd | Manufacturing | 2021 |
| Ilios Holdings Limited | Real estate | 2002 |
| Illuminate-Ed Psychology Services Ltd | Education | 2023 |
| Immutable Clinical Data Solutions Ltd | Information & communication | 2020 |
| Impart TT Limited | Information & communication | 2014 |
| Impec Developments Ltd | Real estate | 2015 |
| Impec Investments Ltd | Construction | 2015 |
| Impec Regeneration Ltd | Real estate | 2025 |
| Imperial Drivers Ltd | Administrative & support | 2020 |
| Imperial Healthcare (NE) Ltd | Administrative & support | 2021 |
| Imperial Industrial Ltd | Other services | 2017 |
| Imperial Professionals Ltd | Administrative & support | 2016 |
| Imperial Recruitment Group Ltd | Administrative & support | 2019 |
| Imperial Workforce Ltd | Administrative & support | 2017 |
| Impressed Laundry & Ironing Services Ltd | Real estate | 2022 |
| Improve Energy Ltd | Professional & scientific | 2016 |
| IMR Letting Limited | Real estate | 2011 |
| IMR Networks Ltd | Information & communication | 2021 |
| IN Safety Ltd | Professional & scientific | 2023 |
| INA Network Ltd | Information & communication | 2020 |
| Inator Ltd | Information & communication | 2025 |
| Inbiz JOB Create Limited | Education | 2015 |
| Inbond Document Management Ltd | Transport & logistics | 2009 |
| Inbond Holdings (NE) Limited | Transport & logistics | 2014 |
| Inbond Limited | Transport & logistics | 2003 |
| Included Education Solutions Limited | Education | 2025 |
| Ind-Spection Services Ltd | Professional & scientific | 2012 |
| Independent Education Welfare Officers Ltd | Education | 2013 |
| Independent Inspection Services NE Ltd | Professional & scientific | 2016 |
| Indepth Imaging Limited | Health & social care | 2011 |
| Indian Food Parade Limited | Hospitality | 2025 |
| Indigo Rebel Films LLP | | 2017 |
| Indigo Rebel Limited | Hospitality | 2013 |
| Indigo Spark Limited | Information & communication | 2020 |
| Indy Partners Limited | Health & social care | 2024 |
| Infinite Vision Media Ltd | Professional & scientific | 2025 |
| Infiniti Group NE Ltd | Transport & logistics | 2022 |
| Infinity Print & Mail Limited | Manufacturing | 2016 |
| Infoarc Limited | Information & communication | 2010 |
| Infrastructure Services Group Limited | Information & communication | 2014 |
| Ingelby Barwick Renewables Ltd | Professional & scientific | 2026 |
| Ingers Group Ltd | Real estate | 2022 |
| Ingleby Automotive Ltd | Wholesale & retail | 2025 |