| I Dunt Ltd | Wholesale & retail | 2024 |
| I J Locums Ltd | Wholesale & retail | 2025 |
| I N Look Limited | Wholesale & retail | 2019 |
| I P Communications Ltd | Information & communication | 2011 |
| I P S Converters Limited | Manufacturing | 1963 |
| I&Ih Ltd | Wholesale & retail | 2023 |
| I&J Holdings Ltd | Financial services | 2017 |
| I&S Real Estate Ltd | Real estate | 2024 |
| I-Solve Software Solutions Limited | Information & communication | 2014 |
| I.I.D Betco Ltd | Transport & logistics | 2026 |
| I.I.S.A NW Ltd | Professional & scientific | 2024 |
| I.M.P.A.C.T Security Ltd | Administrative & support | 2024 |
| I.S.A Logistics Ltd | Transport & logistics | 2026 |
| I.Singleton Transport Limited | Transport & logistics | 2004 |
| IA Housing Ltd | Real estate | 2022 |
| IA Smiles Ltd | Health & social care | 2014 |
| IAA Solicitors Limited | Professional & scientific | 2021 |
| IAH Consultants Ltd | Other services | 2022 |
| IAH Investments Ltd | Real estate | 2024 |
| Iain Howarth Building Services Limited | Construction | 2017 |
| IAM Capital Limited | Real estate | 2015 |
| IAM Utilities Limited | Energy | 2016 |
| Iamchange Limited | Professional & scientific | 2016 |
| IAN Birch Healthcare Limited | Health & social care | 2023 |
| IAN Cline Limited | Health & social care | 2011 |
| IAN Farrell Agencies Ltd | Wholesale & retail | 2010 |
| IAN Tunnicliffe Building Consultancy Ltd | Professional & scientific | 2017 |
| IAS Global Ltd | Professional & scientific | 2014 |
| Ibasho Collectibles Ltd | Wholesale & retail | 2025 |
| Ibby Builders Ltd | Construction | 2023 |
| Ibbysevents Ltd | Manufacturing | 2025 |
| Ibrahim Developments Ltd | Construction | 2025 |
| Ibreathe PAY Ltd | Financial services | 2026 |
| Ibreathe Retail Ltd | Wholesale & retail | 2021 |
| IBY & AH Ltd | Wholesale & retail | 2025 |
| IC Electrical Solutions Ltd | Construction | 2016 |
| Icarion Ltd. | Professional & scientific | 2016 |
| ICB CIC | Real estate | 2022 |
| Ice PAN Oldham Ltd | Real estate | 2017 |
| Iceboxdesigns Ltd | Information & communication | 2013 |
| Icon Project Solutions Ltd | Administrative & support | 2018 |
| Iconnect Electrical Services UK Limited | Energy | 2017 |
| Icontact Limited | Administrative & support | 2010 |
| Icrm Limited | Professional & scientific | 2003 |
| ICS a Ltd | Professional & scientific | 2019 |
| ICY SZN Ltd | Professional & scientific | 2019 |
| Ideal Cars Oldham Ltd | Extraterritorial | 2021 |
| Ideal Crystal Limited | Information & communication | 2024 |
| Ideal Home Furnishing Ltd | Wholesale & retail | 2020 |
| Ideal Roofers Ltd | Construction | 2021 |
| Ideal Training Solutions Ltd | Education | 2023 |
| Ideas Solutions (Retail) Limited | Wholesale & retail | 2010 |
| Identiqo Ltd | Information & communication | 2025 |
| Ideos Care Agency Ltd | Health & social care | 2024 |
| Idil Services Limited | Hospitality | 2023 |
| Idowu Medical Services Ltd | Health & social care | 2017 |
| IFA Logistics Limited | Transport & logistics | 2019 |
| IFS Accounting Ltd | Professional & scientific | 2020 |
| Ifsah Limited | Health & social care | 2024 |
| Ifygold Ltd | Health & social care | 2021 |
| IG Marketing and Education Solutions Ltd | Professional & scientific | 2018 |
| Iglobal Education Training & Recruitment Limited | Professional & scientific | 2014 |
| Igniting Futures Ltd | Education | 2026 |
| Ignition Property Group Ltd | Real estate | 2023 |
| IGP Care Limited | Health & social care | 2014 |
| Igpc Limited | Health & social care | 2023 |
| IGS Services ENG Ltd | Construction | 2020 |
| Igsf Socials Ltd | Professional & scientific | 2025 |
| Igspotlight Ltd | Information & communication | 2025 |
| Igwe Limited | Wholesale & retail | 2022 |
| Ihire NW Ltd | Administrative & support | 2023 |
| IHK Property Limited | Real estate | 2024 |
| Iiaz Properties Limited | Real estate | 2026 |
| Iimm Corp. Ltd. | Construction | 2023 |
| Iiql Ltd | Education | 2010 |
| Iisb Ltd | Education | 2024 |
| Iizaar Couriers Ltd | Transport & logistics | 2025 |
| Iizaar Transport Ltd | Transport & logistics | 2025 |
| Iizar Couriers Ltd | Transport & logistics | 2023 |
| Ij-Fingerlicking Catering Services Ltd | Hospitality | 2022 |
| IK Electric Ltd | Construction | 2025 |
| IK GAS Maintenance Ltd | Construction | 2023 |
| IK MOT Ltd | Wholesale & retail | 2022 |
| IK Motors MCR Ltd | Wholesale & retail | 2024 |
| IK Network Solution Limited | Information & communication | 2012 |
| IK Optical Ltd | Health & social care | 2023 |
| IK Solutions PVT Ltd | Wholesale & retail | 2024 |
| IK Tracks Ltd | Administrative & support | 2025 |
| Ikbal Limited | Professional & scientific | 2019 |
| Ikei's Treats Ltd | Arts & recreation | 2021 |
| Ikennaji Investment Ltd | Construction | 2019 |
| IKJ Contractors Ltd | Construction | 2024 |
| Ikkan Sushi Ltd | Hospitality | 2022 |
| IKV Limited | Extraterritorial | 2009 |
| IKZ Properties Ltd | Real estate | 2024 |
| Ilios Money Management Ltd | Financial services | 2022 |
| Illicit Labs Limited | Information & communication | 2024 |
| Ilsa Events Ltd | Arts & recreation | 2023 |
| IM Building Ltd | Other services | 2015 |
| IM Firm Ltd | Wholesale & retail | 2024 |