| Inspire Driving - Local Instructors Ltd | Education | 2026 |
| Inspire School of Homeopathic Practice Ltd | Education | 2026 |
| Inspired Film and Video Limited | Information & communication | 2006 |
| Inspired Leaders Ltd | Professional & scientific | 2023 |
| Instagadgets Ltd | Wholesale & retail | 2019 |
| Installforce Ltd | Wholesale & retail | 2023 |
| Instant Loos Limited | Administrative & support | 2023 |
| Instant Tool and Plant Hire Limited | Administrative & support | 2019 |
| Instantflow Emergency Plumbers Limited | Construction | 2025 |
| INSTIG8 Ltd | Administrative & support | 2018 |
| Instinct Accountancy Limited | Professional & scientific | 2025 |
| Instyle Living Limited | Wholesale & retail | 2018 |
| Inteck Products Limited | Manufacturing | 1994 |
| Intelligent Parameters Ltd | Professional & scientific | 2023 |
| Inter-Engineering (UK) Limited | Professional & scientific | 2008 |
| Interactive Contact & Resolution Limited | Professional & scientific | 2020 |
| Intercede Holdings Limited | Professional & scientific | 2017 |
| Intercede Middle East Investments Limited | Professional & scientific | 2017 |
| Intercity Private Hire Ltd | Transport & logistics | 2025 |
| Interflor UK Limited | Construction | 2011 |
| Interlockdigital Ltd | Information & communication | 2009 |
| International Petrogas Company Ltd | Mining & quarrying | 2025 |
| International Road Rescue and Trauma Consultancy Ltd. | Education | 2017 |
| Interveritas Ltd | Real estate | 2025 |
| Intravenous Drips UK Ltd | Health & social care | 2025 |
| Intruder Detection Systems Limited | Administrative & support | 2002 |
| Inverted Normals Ltd | Information & communication | 2018 |
| Investco Land Investments Limited | Real estate | 2020 |
| Investormatch Ltd | Professional & scientific | 2026 |
| Investors for Change Ltd | Education | 2024 |
| Inviting Homes Ltd | Real estate | 2019 |
| Invoke Smart Homes Ltd | Construction | 2015 |
| Inwar Trading and Consultation Ltd | Real estate | 2024 |
| Ionut Bogdan Iliescu Ltd | Transport & logistics | 2022 |
| Iordan Transport Limited | Transport & logistics | 2021 |
| Iot.Nxt UK Limited | Information & communication | 2022 |
| IP Freedom Ltd | Real estate | 2016 |
| IP Harrogate OPO Limited | Real estate | 2022 |
| IP Knutsford Development Limited | Construction | 2020 |
| IP Springfield Warrington Ltd | Real estate | 2022 |
| IP the Paddocks Ltd | Construction | 2021 |
| Ipsum BLU Limited | Construction | 2023 |
| Iqbal Karim Limited | Real estate | 2024 |
| Iraseef Limited | Wholesale & retail | 2026 |
| Irelands Cross Development Limited | Construction | 2025 |
| Irene Pizza Nights Ltd | Hospitality | 2025 |
| Irene Samuel Care Services Ltd | Health & social care | 2023 |
| IRH Design Limited | Professional & scientific | 2007 |
| Irie Kitchen Ltd | Hospitality | 2025 |
| Iron Sparks UK Ltd | Construction | 2026 |
| Ironblack Ltd | Real estate | 2025 |
| Ironbridge Interiors (Newport) Ltd | Wholesale & retail | 2020 |
| Ironmarket Risk Management Limited | Financial services | 2020 |
| IS Car Sales Limited | Wholesale & retail | 2025 |
| ISA Healthcare Limited | Wholesale & retail | 2024 |
| ISA Properties Limited | Real estate | 2022 |
| Isaac Golden Fish Bar Ltd | Hospitality | 2020 |
| Isc-Uk Ltd | Professional & scientific | 2024 |
| Isherwood Electrical Limited | Construction | 2017 |
| Ishfaq Arif W.Shops Tools TR UK Ltd | Wholesale & retail | 2023 |
| Ishs Property Investment Limited | Real estate | 2024 |
| Islam Properties Limited | Real estate | 2013 |
| Islands Charm Ltd | Wholesale & retail | 2022 |
| Isleinnovate Ltd | Wholesale & retail | 2024 |
| ISM Design & Build Limited | Construction | 2019 |
| Ismail Ltd | Health & social care | 2025 |
| Ismaylov Limited | Health & social care | 2025 |
| ISO Compliance & Certification Ltd | Professional & scientific | 2020 |
| Isodirect Ltd | Professional & scientific | 2003 |
| Ispb Ltd | Hospitality | 2024 |
| Israr Idres Ltd | Professional & scientific | 2019 |
| Isware Limited | Information & communication | 2006 |
| IT Distribution Online Ltd | Wholesale & retail | 2021 |
| IT PC Support Limited | Information & communication | 2019 |
| It's ALL About ME UK CIC | Professional & scientific | 2022 |
| It's ALL About Me..Me..Me.. Limited | Other services | 2015 |
| It's What YOU SAY CIC | Education | 2017 |
| Italobritish Investments Ltd | Wholesale & retail | 2022 |
| Itera Design Network Ltd | Wholesale & retail | 2022 |
| Itlity - Hvdc Consultants Limited | Professional & scientific | 2020 |
| Itnextlogic Ltd | Wholesale & retail | 2025 |
| Itradegenius Ltd | Wholesale & retail | 2023 |
| Itravel Taxi Private Hire Ltd | Transport & logistics | 2019 |
| Itrust Home Improvements UK Ltd | Construction | 2016 |
| ITS Good Scents Limited | Wholesale & retail | 2023 |
| Itsg Ltd | Information & communication | 2011 |
| IUI Security Limited | Construction | 2017 |
| Iurcutek Ltd | Construction | 2025 |
| Ivape Longton Limited | Wholesale & retail | 2016 |
| Ivape Tunstall Limited | Wholesale & retail | 2016 |
| Ivape Wholesale Limited | Wholesale & retail | 2019 |
| Ivape.Delivery Limited | Wholesale & retail | 2023 |
| IVY & Stone Property Group Ltd | Real estate | 2025 |
| IVY House Commercial Developments Limited | Financial services | 2024 |
| IVY House Holdings Limited | Professional & scientific | 1997 |
| IVY ROW Properties Ltd | Real estate | 2022 |
| Iwashrooms Limited | Wholesale & retail | 2011 |
| Iwebwiser Ltd | Information & communication | 2025 |
| Iyondo Ltd | Information & communication | 2019 |
| Izaak Walton Brewhouse Limited | Manufacturing | 2019 |