| Incoming Social Ltd | Information & communication | 2025 |
| Incorporated Association of Organists(The) | Education | 1929 |
| Incotech Limited | Manufacturing | 1993 |
| Increase and Growth Ltd | Health & social care | 2026 |
| Inder Ltd | Information & communication | 2009 |
| Inder Superstore Ltd | Wholesale & retail | 2020 |
| Inderpal Johal Limited | Health & social care | 2015 |
| Indi Property Consulting Ltd | Real estate | 2026 |
| Indian Food Fousin Ltd | Hospitality | 2025 |
| Indian Ocean Development Corporation Limited | Financial services | 2020 |
| Indian Tarka Ltd | Hospitality | 2025 |
| Indibites (Bridgnorth) Limited | Hospitality | 2020 |
| Indigo Visual Solutions Ltd | Manufacturing | 2022 |
| Indus Real Estate Investments Limited | Real estate | 2016 |
| Industrial Clothing (WR) Limited | Wholesale & retail | 2002 |
| Industrial Flooring Contractors Ltd | Construction | 2023 |
| Industrial Solutions Workwear Limited | Administrative & support | 2006 |
| Industrial Talent Limited | Professional & scientific | 2026 |
| INDUSTRY4SYSTEMS Ltd | Information & communication | 2026 |
| Indy Sagoo Photography Limited | Professional & scientific | 2013 |
| Inescon Group Ltd | Wholesale & retail | 2019 |
| INFINI8Y Ltd | Wholesale & retail | 2025 |
| Infinitee Homes Ltd | Real estate | 2024 |
| Infiniti AI Ltd | Professional & scientific | 2024 |
| Infinity FOX Ltd | Real estate | 2025 |
| Infinity Performance Parts Limited | Wholesale & retail | 2021 |
| Infinitytransport Ltd | Transport & logistics | 2025 |
| Infinityy Energy Group Ltd | Construction | 2023 |
| Inflection & Co. Ltd | Professional & scientific | 2026 |
| Infrared Heating Contractors Limited | Construction | 2024 |
| Infrastructure Gateway Limited | Construction | 2002 |
| Ingeni Renewables Limited | Construction | 2023 |
| Ingenium Performance Limited | Arts & recreation | 2026 |
| Ingleby (1084) Limited | Professional & scientific | 1998 |
| Ingleside Cottage Holdings Limited | Real estate | 2025 |
| Inha Investments Ltd | Real estate | 2025 |
| Inhouse Calls Ltd | Administrative & support | 2023 |
| Inim Electronics (UK) Limited | Manufacturing | 2012 |
| INK Eightyeight Ltd | Arts & recreation | 2023 |
| Inklifewalsall Ltd | Other services | 2014 |
| Inkredible Muzik Limited | Information & communication | 2024 |
| Inmotion Camps & School Partnerships Ltd | Education | 2026 |
| Inna Change CIC | Education | 2025 |
| Inner Calm Therapy Ltd | Other services | 2021 |
| Inner Game Mentor Limited | Manufacturing | 2025 |
| Innervated Vehicle Engineering Limited | Manufacturing | 2020 |
| Innohunt Limited | Health & social care | 2024 |
| Innoserve Solutions Limited | Manufacturing | 2024 |
| Innovaai Integration Ltd | Information & communication | 2025 |
| Innovapharm Limited | Health & social care | 2024 |
| Innovate Learning Centre CIC | Education | 2006 |
| Input Output Things Limited | Information & communication | 2020 |
| Insight Health Services Ltd | Health & social care | 2024 |
| Insight Home Solutions Ltd | Construction | 2026 |
| Insignia Retail Limited | Hospitality | 2017 |
| Inspcakes Ltd | Manufacturing | 2024 |
| Inspiraction Limited | Real estate | 2001 |
| Inspire (Walsall) Limited | Education | 2013 |
| Inspire 2 Quit Blades CIC | Education | 2019 |
| Inspired Bathrooms & Plumb Centre Ltd | Wholesale & retail | 2018 |
| Inspired Keys Ltd | Real estate | 2025 |
| INSPIREME2BE Ltd | Education | 2010 |
| Inspirespace Community Interest Company | Professional & scientific | 2012 |
| Inspiring Minds Centre Ltd | Education | 2025 |
| Inspiring the Next Generation Limited | Other services | 2017 |
| Insta PIX Ltd | Professional & scientific | 2025 |
| Instant Acorn Technologies Ltd | Administrative & support | 2024 |
| Instore Healthcare Limited | Extraterritorial | 2025 |
| Instructures Limited | Manufacturing | 2004 |
| Intal Decorators (UK) Ltd | Other services | 2013 |
| Intal Decorators Ltd | Other services | 2011 |
| Intasprint Ltd | Wholesale & retail | 2007 |
| Integrated Tanker Services Limited | Administrative & support | 1981 |
| Integrated Water Services Limited | Water & waste | 2004 |
| Integrity Klinny Ltd | Administrative & support | 2025 |
| Integrity Repairs Ltd | Construction | 2024 |
| Intellect Intelligence Ltd | Administrative & support | 2017 |
| Intensiv Filter Himenviro (UK) Ltd. | Professional & scientific | 1999 |
| Inter Green Energy Ltd | Construction | 2020 |
| Inter-Christian Fellowship CC Ltd | Education | 2020 |
| Inter-Credit International Limited | Administrative & support | 1971 |
| Intercity Finance (UK) Limited | Financial services | 1996 |
| Interface Engravers Limited | Manufacturing | 2006 |
| Interface Signage Limited | Manufacturing | 2002 |
| Intergrated Accountancy Limited | Financial services | 2014 |
| Interior Hardware Limited | Wholesale & retail | 2001 |
| Interior Solutions Midlands Limited | Construction | 2000 |
| Interior Solutions WM Ltd | Construction | 2024 |
| Interiors Today Limited | Manufacturing | 2018 |
| International Exotics Limited | Wholesale & retail | 2003 |
| International Federation of Swimming Teachers Associations Limited(The) | Other services | 1977 |
| International Nonwovens Limited | Wholesale & retail | 2016 |
| International Rabota Ltd | Professional & scientific | 2025 |
| International Supermarket WM Ltd | Wholesale & retail | 2019 |
| Interpower Induction Ltd | Manufacturing | 1992 |
| Intiri Solutions Limited | Professional & scientific | 2021 |
| Intown Logistics Limited | Transport & logistics | 2022 |
| Intown Motors Ltd | Wholesale & retail | 2024 |
| Intracoronal Ltd | Health & social care | 2023 |
| Invent Design Ltd | Manufacturing | 2010 |