| IDJ Salons & Spas Limited | Other services | 2018 |
| IDK Properties Ltd | Real estate | 2024 |
| IDP Care Limited | Professional & scientific | 2019 |
| Idpino Ltd | Wholesale & retail | 2025 |
| Idris Car Tech Limited | Manufacturing | 2015 |
| Idris Community Services Ltd | Manufacturing | 2025 |
| Idris Constructons Ltd | Construction | 2026 |
| Idris Godfather Ltd | Real estate | 2022 |
| IDV Motors Ltd | Wholesale & retail | 2023 |
| Idyllic Classics Limited | Wholesale & retail | 2018 |
| IE Brand and Digital Limited | Extraterritorial | 2019 |
| IE Brand Limited | Extraterritorial | 2019 |
| IE Creative Limited | Arts & recreation | 2002 |
| IE Design Consultancy Limited | Information & communication | 2004 |
| IE Design Limited | Professional & scientific | 2010 |
| IE Design Trustee Ltd | Professional & scientific | 2025 |
| IE Logistics Ltd | Wholesale & retail | 2025 |
| IE London College Limited | Education | 2026 |
| IEA Coal Research Limited | Professional & scientific | 1975 |
| IEB Properties Ltd | Real estate | 2020 |
| Iedu Training Academy Ltd | Professional & scientific | 2024 |
| Ieducationtutors Ltd | Education | 2024 |
| Iell Limited | Education | 2026 |
| IEM Bishops Stortford Ltd | Education | 2019 |
| IEM Cambridge Ltd | Education | 2019 |
| IEM Cardiff Ltd | Education | 2018 |
| IEM Communications Limited | Education | 2000 |
| IEM Group Holdings Ltd | Financial services | 2026 |
| IEM Leicester Limited | Education | 2017 |
| IEM Northampton Ltd | Education | 2019 |
| IEM Nottingham Limited | Education | 2017 |
| IEM Property Investments Ltd | Real estate | 2020 |
| IEM Tutoring Ltd | Administrative & support | 2020 |
| IEM Yorkshire Ltd | Education | 2019 |
| Iesk Limited | Administrative & support | 2017 |
| IET and Services Ltd | Hospitality | 2023 |
| IF and Only IF Ltd | Information & communication | 2017 |
| IF Design Limited | Professional & scientific | 2026 |
| IF YOU Don'T Mind Ltd | Arts & recreation | 2017 |
| IFA Reports Ltd | Professional & scientific | 2012 |
| Ifaas UK Limited | Professional & scientific | 2007 |
| IFC Frozen and Chilled Foods Limited | Wholesale & retail | 2013 |
| Ifems Clean Energy Consultancy Limited | Information & communication | 2023 |
| Ifet Travel and Tours International Ltd | Administrative & support | 2019 |
| Ifie Limited | Health & social care | 2012 |
| Ifix Birmingham 1 Ltd | Other services | 2025 |
| Ifix MOB Ltd | Wholesale & retail | 2025 |
| IFJ Global Limited | Information & communication | 2018 |
| IFL Brands Ltd | Professional & scientific | 2016 |
| IFL Global Ltd | Wholesale & retail | 2017 |
| Ifloss.Co.Uk Ltd | Health & social care | 2012 |
| Iflt LAB Ltd | Manufacturing | 2025 |
| IFO Foods Limited | Hospitality | 2025 |
| Ifood London Ltd | Wholesale & retail | 2023 |
| Iforensic Limited | Professional & scientific | 2007 |
| Ifounddeals Ltd | Professional & scientific | 2022 |
| IFP Development & Commercial Ltd | Professional & scientific | 2021 |
| IFP Systems Ltd | Public administration | 2019 |
| Ifrah.Z Locum Limited | Administrative & support | 2023 |
| Ifraz Jewellers Limited | Wholesale & retail | 2003 |
| Ifraz Limited | Wholesale & retail | 2026 |
| Ifrim Driver Ltd | Other services | 2017 |
| IFS Global Marketing Limited | Real estate | 2008 |
| IFS Investment Holdings Ltd | Financial services | 2026 |
| IFS Spirits Ltd | Wholesale & retail | 2024 |
| Ifta Limited | Administrative & support | 2008 |
| Iftaza Limited | Administrative & support | 2020 |
| Ifthakhar Hussain Limited | Health & social care | 2021 |
| Ifti 226 Limited | Wholesale & retail | 2026 |
| Iftikhar Choudhury Ltd | Wholesale & retail | 2018 |
| Iftikhar Investments Ltd | Real estate | 2024 |
| Iftikhar Medical Services Limited | Real estate | 2015 |
| Iftin Ltd | Wholesale & retail | 2025 |
| IFTKHAR23 Ltd | Wholesale & retail | 2025 |
| Ifton Green Resident Management Company Limited | Households | 2024 |
| Ifty Ltd | Other services | 2024 |
| IG Convenience (Hall Green) Ltd | Wholesale & retail | 2019 |
| IG Group Birmingham Limited | Wholesale & retail | 2026 |
| IG Rentals Ltd | Administrative & support | 2026 |
| Ig-Nite Power Ltd | Construction | 2012 |
| Igambovic Logistics International Ltd | Transport & logistics | 2025 |
| Igas Heating Solutions Ltd | Construction | 2022 |
| Igbo Valencianos UK | Other services | 2026 |
| IGC Property Solutions Ltd | Construction | 2018 |
| Igennex Limited | Professional & scientific | 2001 |
| Iggy Nomad Logistics Ltd | Transport & logistics | 2025 |
| IGJ Limited | Construction | 2024 |
| IGL Materials Ltd | Wholesale & retail | 2026 |
| Igloo App Ltd | Information & communication | 2025 |
| Iglu Cottages Ltd | Health & social care | 2024 |
| Iglume Limited | Professional & scientific | 2019 |
| Igna-Locksmiths Ltd | Wholesale & retail | 2023 |
| Ignacio Travel Ltd | Administrative & support | 2025 |
| Igni GAS Services Ltd | Construction | 2026 |
| Ignis Electrical Services Limited | Construction | 2016 |
| Ignis Fire and Safety Limited | Financial services | 2025 |
| Ignis Growth Limited | Professional & scientific | 2017 |
| Ignital Solutions Limited Limited | Construction | 2007 |
| Ignite AI Ltd | Information & communication | 2025 |
| Ignite Assets Ltd | Real estate | 2026 |