| Ibramlimited Ltd | Wholesale & retail | 2026 |
| ICC Accountancy Ltd | Professional & scientific | 2001 |
| Ice Global Engineering Services Limited | Professional & scientific | 2019 |
| Ice Pro Detailing Ltd | Wholesale & retail | 2024 |
| ICE32 Limited | Information & communication | 2009 |
| ICODE4U Consulting Ltd | Information & communication | 2017 |
| Icon Hair Company Ltd | Other services | 2020 |
| Iconic Beauty & Wellbeing CIC | Education | 2026 |
| Iconic Improvements Limited | Construction | 2023 |
| Iconic Pictures Limited | Information & communication | 2023 |
| Iconic Projects Limited | Construction | 2020 |
| Icrack Bournemouth Ltd | Real estate | 2020 |
| Idahs the Artisan Bakery Limited | Manufacturing | 2021 |
| Iddesleigh Lodge Development Company Limited | Households | 2003 |
| Idea Cabinet Ltd | Information & communication | 2015 |
| Ideal Plumbing Systems Ltd | Construction | 2011 |
| Idiosyncratic Media Limited | Information & communication | 2021 |
| Idmiston Road Management Company Limited | Households | 2020 |
| Idyllic Aurora Ltd | Manufacturing | 2019 |
| IFF International Furniture Fittings Ltd | Manufacturing | 1995 |
| Ifightfor CIC | Wholesale & retail | 2014 |
| IFJ Management Ltd | Administrative & support | 2026 |
| Iford Golf Centre Ltd | Arts & recreation | 2024 |
| Iford Investments Limited | Hospitality | 2011 |
| Iford Road Developments Limited | Construction | 2007 |
| IFR Finance Limited Partnership | | 1998 |
| Iften Ltd | Extraterritorial | 2021 |
| IFY Fawaz Care Ltd | Health & social care | 2023 |
| Igit Limited | Real estate | 2011 |
| Igocorp Limited | Energy | 2020 |
| Igoyugo Limited | Wholesale & retail | 2024 |
| Igreja Cristã Nova Aliança | Other services | 2009 |
| IK Aesthetic Clinic Limited | Other services | 2024 |
| IKJ Consulting Limited | Information & communication | 2025 |
| Ikon Group (Wessex) Ltd | Construction | 2008 |
| Ikon Group (Wimbledon) Limited | Construction | 2024 |
| Ikon Holdings Limited | Construction | 2024 |
| Ikon Property (Wessex) Ltd | Construction | 2018 |
| Ikonic Construction Limited | Construction | 2020 |
| IL Mondo Gelato and Woodstone Ltd | Wholesale & retail | 2015 |
| Ilbey Training International Limited | Administrative & support | 2008 |
| Iletrooms (Eldon) Limited | Real estate | 2014 |
| Iletrooms (Heron) Limited | Hospitality | 2012 |
| Ilike Media Ltd | Professional & scientific | 2011 |
| Illas Industries Ltd | Wholesale & retail | 2017 |
| Illegal Art Boutique Limited | Professional & scientific | 2013 |
| Illustro Consultancy Ltd | Professional & scientific | 2017 |
| Ilmy Ltd | Wholesale & retail | 2019 |
| IM Travel (IMT) Limited | Administrative & support | 2009 |
| Imaan Investment Corporation Limited | Real estate | 2017 |
| Imadlo Ltd | Other services | 2024 |
| Image Inspection UK Limited | Construction | 2008 |
| Image Management Services Ltd | Professional & scientific | 2002 |
| Image Tech Limited | | 1986 |
| Images Freehold Limited | Households | 2014 |
| Imagine & Transform Limited | Administrative & support | 2025 |
| Imago Developments Limited | Construction | 2011 |
| Imajin Studios Ltd | Information & communication | 2025 |
| IMC Analysts LLP | | 2024 |
| IMC Assessors Ltd | Health & social care | 2015 |
| Immaculate Home Improvements (South) Ltd | Construction | 2025 |
| Immaculate Intelligence Ltd | Information & communication | 2025 |
| Immat Limited | Administrative & support | 2007 |
| Immediate Building Services Ltd | Construction | 2004 |
| Immense Events & Bars Ltd | Arts & recreation | 2013 |
| Immersive Structures Limited | Construction | 2023 |
| Imonyx Ltd | Manufacturing | 2024 |
| Impact Acoustics Ltd | Professional & scientific | 2012 |
| Imperial Fabrication Ltd | Wholesale & retail | 2025 |
| Imperial Guild Ltd | Professional & scientific | 2022 |
| Imperial Heights (Canford Cliffs) Management Company Limited | Real estate | 2009 |
| Impressions Care Solutions Limited | Health & social care | 2020 |
| Imprint Home Improvements Limited | Construction | 2025 |
| IMZ Solutions Ltd | Information & communication | 2019 |
| IN Health Supplements Limited | Health & social care | 2021 |
| IN Key Consulting Limited | Information & communication | 2013 |
| IN Shape Hair Studio Limited | Other services | 2013 |
| IN Site Ltd | Public administration | 2024 |
| IN2PHONE Ltd | Wholesale & retail | 2025 |
| Inasalon Ltd | Other services | 2023 |
| Inceptus Limited | Information & communication | 2001 |
| Incito Systems Ltd | Information & communication | 2005 |
| Inclusionin Limited | Professional & scientific | 2021 |
| Inclusiride Ltd | Transport & logistics | 2026 |
| Inclusive Impact Holdings Limited | Financial services | 2025 |
| Inclusive Impact Trustees Limited | Other services | 2025 |
| Inco Solutions Limited | Information & communication | 2016 |
| Increase the Peace Community C.I.C. | Administrative & support | 2022 |
| Incrowd Events Ltd | Hospitality | 2021 |
| Incups Coffee Limited | Hospitality | 2022 |
| Independent Arts Enterprises CIC | Wholesale & retail | 2025 |
| Independent Carers Services Ltd | Health & social care | 2023 |
| Independent EAR Care Ltd | Wholesale & retail | 2025 |
| Independent Mortgage Solutions (Hampshire) Limited | Administrative & support | 2006 |
| Independent Publishers Alliance Ltd. | Other services | 2021 |
| Index AI Ltd | Professional & scientific | 2025 |
| Index Marine Equipment Limited | Wholesale & retail | 2008 |
| Indi's Restaurant Limited | Hospitality | 2003 |
| Indievet Limited | Wholesale & retail | 2025 |
| Indigo Bournemouth Limited | Administrative & support | 2016 |