| IAN Caminsky Consulting Ltd | Professional & scientific | 2025 |
| IAN Cartwright Consulting Ltd | Professional & scientific | 2022 |
| IAN Kelsey Editing Ltd | Information & communication | 2008 |
| IAN Scott Photography Ltd | Professional & scientific | 2013 |
| IB Goalkeeping Limited | Arts & recreation | 2023 |
| Ibbcomm Cabling Ltd | Administrative & support | 2017 |
| Ibdas Engineering Limited | Information & communication | 2016 |
| IBN Good Food Limited | Wholesale & retail | 2024 |
| IBO North Ltd | Hospitality | 2025 |
| Ibogenics Limited | Professional & scientific | 2024 |
| IBT Technologies Ltd | Information & communication | 2024 |
| Icarus Logic Limited | Information & communication | 2023 |
| Iceberg Coaching Ltd | Administrative & support | 2009 |
| Ichef Recruitment Limited | Hospitality | 2024 |
| Icloud Technology Ltd | Administrative & support | 2011 |
| Icon Technology Holdings Ltd | Information & communication | 2026 |
| Icon Value Added Distribution Ltd | Information & communication | 1992 |
| Iconic Products Limited | Wholesale & retail | 2023 |
| ICT Network Limited | Information & communication | 2025 |
| IDE Contracting Limited | Construction | 2000 |
| Ideal Glass Limited | Construction | 2023 |
| Idealedu Limited | Education | 2022 |
| Idev Consulting Ltd | Information & communication | 2001 |
| IDV Plumbing and Heating Ltd | Construction | 2018 |
| IFM Consulting (UK) Ltd. | Professional & scientific | 2014 |
| IGNITION2 Limited | Professional & scientific | 2025 |
| IJK Infra Ltd | Real estate | 2026 |
| Ikigai Ventures I LP | | 2022 |
| Ikons Trading Ltd | Administrative & support | 2004 |
| Illimani Consulting Limited | Public administration | 2020 |
| Illogical Limited | Professional & scientific | 2023 |
| Illsun Consulting and Collectables Intl Ltd | Professional & scientific | 2021 |
| Illuminarty Limited | Wholesale & retail | 2009 |
| Image & Pulp Ltd | Wholesale & retail | 2015 |
| Images of Development Consulting Limited | Wholesale & retail | 2011 |
| Imagetec Limited | Manufacturing | 2014 |
| Imaginos NDE Limited | Professional & scientific | 2011 |
| Imbas Learning and Performance Limited | Professional & scientific | 2025 |
| Imea Services Ltd | Professional & scientific | 2024 |
| Immages Limited | Real estate | 1998 |
| Immersive FOX MCC SPV1 LLP | | 2023 |
| IMP4CT Ltd | Administrative & support | 2011 |
| Impact CAP LLP | | 2025 |
| Impact Traffic Management Ltd | Transport & logistics | 2025 |
| Impactix Investigations Limited | Professional & scientific | 2022 |
| Impeller Limited | Professional & scientific | 2013 |
| Imperial Equine Transport Ltd | Transport & logistics | 2025 |
| Imperium Accountancy Practice Limited | Professional & scientific | 2020 |
| Imperium Asset Group Ltd | Professional & scientific | 2019 |
| Imperium CIS Limited | Construction | 2020 |
| Imperium Contractor Solutions Limited | Professional & scientific | 2020 |
| Imperium PR Limited | Professional & scientific | 2020 |
| Impex Enterprises Limited | Wholesale & retail | 2013 |
| Impulse Property Solutions Limited | Real estate | 2022 |
| IMS Commercial Ltd | Financial services | 2023 |
| IMS Estate Planning Ltd | Financial services | 2024 |
| IMS Financial Limited | Financial services | 2025 |
| IMS House Ltd | Real estate | 2024 |
| IN Capital - Gfo-X Series (B) 2023 LLP | | 2023 |
| IN Good Measure Ltd | Administrative & support | 2009 |
| IN. Capital I LLP | | 2023 |
| Inclusive Dreams Community Interest Company | Health & social care | 2023 |
| Indeo Construction Services Limited | Professional & scientific | 2022 |
| Indeo Contracting Limited | Construction | 2025 |
| Indeo Equipment Limited | Administrative & support | 2025 |
| Indeo Professional Services Limited | Construction | 2025 |
| Indeo Technologies Limited | Wholesale & retail | 2025 |
| Independent Edge Limited | Professional & scientific | 2005 |
| Indian by Nature Limited | Hospitality | 2024 |
| Indigo Square Consulting Ltd | Professional & scientific | 2012 |
| Indigowares Limited | Wholesale & retail | 2024 |
| Individual Data Limited | Information & communication | 1993 |
| Industrial Brands Limited | Professional & scientific | 2023 |
| Industrial Financings (Essex) Limited | Extraterritorial | 1965 |
| Indy Software Ltd | Information & communication | 2018 |
| Indyprint Limited | Manufacturing | 2014 |
| Infinitum Accounts Limited | Professional & scientific | 2023 |
| Infinity Heritage Ltd | Information & communication | 1994 |
| Infinity Z Limited | Wholesale & retail | 2017 |
| Influra Ltd | Information & communication | 2026 |
| Infrapa Ltd | Energy | 2011 |
| Infuse AI Ltd | Information & communication | 2025 |
| Infuse Recruitment & Training Consultancy Ltd | Administrative & support | 2007 |
| Ingaraffe Ltd | Professional & scientific | 2021 |
| Ingleman Limited | Information & communication | 2023 |
| Inglis Studio Ltd | Information & communication | 2011 |
| Ingram Talent Solutions Ltd | Professional & scientific | 2025 |
| Inhabit Architecture Limited | Professional & scientific | 2007 |
| Inimay Limited | Information & communication | 2026 |
| Initiative Hospitality Limited | Hospitality | 2018 |
| Inkslingers Media Limited | Information & communication | 2018 |
| Inna Voronova Bridal Ltd | Wholesale & retail | 2021 |
| Inner View Development Ltd | Professional & scientific | 2015 |
| Innervision Management Consultancy Limited | Professional & scientific | 2022 |
| Innovation in U Ltd | Professional & scientific | 2015 |
| Innovations Building Design Limited | Construction | 2018 |
| Inolog Limited | Information & communication | 2016 |
| Inovo Works Ltd | Information & communication | 2023 |
| Inside OUT Solutions Ltd | Professional & scientific | 2025 |
| Insideretail Limited | Wholesale & retail | 2011 |