| Indus Restaurant Limited | Hospitality | 2024 |
| Industrial and Commercial Operations Network Ltd | Information & communication | 2018 |
| Industrial Roofing Ltd | Construction | 2024 |
| Industrial Supplies (Steels and Wood) Limited | Transport & logistics | 1990 |
| Inenco Energy Trading Limited | Professional & scientific | 1985 |
| Inenco Group Limited | Professional & scientific | 1989 |
| Inenco Holdings Limited | Professional & scientific | 2004 |
| Inenco Limited | Professional & scientific | 1993 |
| Inerto Ltd | Water & waste | 2018 |
| Infinite Engineering Solutions Limited | Professional & scientific | 2022 |
| Infinite Financial Services Limited | Financial services | 2010 |
| Infinite Magical Minds Ltd | Professional & scientific | 2024 |
| Infinite Software Solutions Ltd. | Wholesale & retail | 2024 |
| Infinite Structured Finance Ltd | Financial services | 2025 |
| Infinite Women CIC | Health & social care | 2022 |
| Infinitgen Ltd | Wholesale & retail | 2024 |
| Infinity Airport Services Limited | Transport & logistics | 2016 |
| Infinity Properties NW Limited | Real estate | 2026 |
| Infinium (Computing) Limited | Information & communication | 2013 |
| Infinium (South West) Limited | Information & communication | 2008 |
| Infinium Group Limited | Information & communication | 2014 |
| Infinium IT Limited | Information & communication | 2002 |
| Inflatable Event Games Ltd | Arts & recreation | 2025 |
| Inflatable Events Ltd | Arts & recreation | 2022 |
| Influx Estates Ltd | Real estate | 2017 |
| Influx Marketing Limited | Professional & scientific | 2025 |
| Information Technology P.R. Limited | Professional & scientific | 1990 |
| Infotechnologies Ltd | Information & communication | 2025 |
| Infovibes Ltd | Information & communication | 2023 |
| Infra Fire Safety Ltd | Professional & scientific | 2024 |
| Infusion Estates Group Limited | Agriculture & fishing | 2012 |
| Infusion Living Limited | Professional & scientific | 2012 |
| Infusion Residential Limited | Professional & scientific | 2012 |
| ING.0FFICIAL Limited | Wholesale & retail | 2025 |
| Ingenious Investment Partners Limited | Professional & scientific | 2019 |
| Ingenium Financial Advisers Limited | Financial services | 2025 |
| Ingenix Leadership Ltd | Hospitality | 2020 |
| Ingenuity Consulting Ltd | Information & communication | 2009 |
| Ingersoll - Rand Holdings Limited | Professional & scientific | 1970 |
| Ingersoll-Rand Company Limited | Administrative & support | 1921 |
| Ingersoll-Rand Services Limited | Wholesale & retail | 1971 |
| Ingestre Court Management Company Limited | Real estate | 1993 |
| Ingham S Limited | Wholesale & retail | 2019 |
| Inglemere Court Management Company Limited | Households | 2021 |
| Inglewhite Developments Ltd | Real estate | 2024 |
| Ingol and Tanterton Community Trust Limited | Health & social care | 2008 |
| Ingol Properties Limited | Other services | 2014 |
| Ingol Social Club Limited | Hospitality | 2025 |
| Inhabinet Ltd | Real estate | 2025 |
| Inhoco 2952 Limited | Real estate | 2003 |
| Initial Technologies Limited | Information & communication | 2002 |
| Initiate Theatre Ltd | Education | 2018 |
| Injectahealth Ltd | Wholesale & retail | 2024 |
| INK Vogue Limited | Wholesale & retail | 2025 |
| Inkjet Inks Ltd | Wholesale & retail | 2008 |
| Inkognito Beauty House Ltd | Other services | 2026 |
| Inkthreadable Limited | Manufacturing | 2013 |
| Inn Fayre Blackburn Limited | Hospitality | 2025 |
| Inn Fayre Garstang Limited | Hospitality | 2025 |
| Inn Fayre Lancaster Limited | Hospitality | 2025 |
| Inn Fayre Preston Limited | Hospitality | 2025 |
| Inner Edge Consulting Limited | Professional & scientific | 2025 |
| Innercity Resource Ltd | Professional & scientific | 2024 |
| Innerdale Ltd | Administrative & support | 2011 |
| Innergy Ltd | Professional & scientific | 2024 |
| Innocent-White Catering Ltd | Hospitality | 2025 |
| INNOV8 (NW) Limited | Construction | 2025 |
| INNOV8 Surfaces Ltd | Professional & scientific | 2017 |
| INNOV8FLOORS Ltd | Extraterritorial | 2005 |
| INNOV8TILECO Limited | Wholesale & retail | 2020 |
| Innovafleet Ltd | Professional & scientific | 2026 |
| Innovate Automotive Network Limited | Wholesale & retail | 2019 |
| Innovate Inns Ltd | Hospitality | 2019 |
| Innovate NW Ltd | Professional & scientific | 2011 |
| Innovation AI Ltd | Information & communication | 2026 |
| Innovation Control (Property) Limited | Real estate | 2012 |
| Innovation in Interiors Limited | Wholesale & retail | 2020 |
| Innovation Leisure Ltd | Manufacturing | 2016 |
| Innovation Technology Ltd | Information & communication | 2025 |
| Innovative Surgical Designs Ltd | Professional & scientific | 2020 |
| Innovative Warehouse Limited | Professional & scientific | 2017 |
| Innoventions Limited | Administrative & support | 2019 |
| Innovest Group Ltd | Health & social care | 2024 |
| Inns & Saloons Limited | Hospitality | 2025 |
| Innventions Kirkland Limited | Hospitality | 2018 |
| Inogrim Ltd | Real estate | 2026 |
| INOV8 Invesments Ltd | Households | 2019 |
| Inpay Services UK Limited | Other services | 2014 |
| Inreach Ltd | Information & communication | 2023 |
| Inscope Project Consultants Limited | Professional & scientific | 2015 |
| Inscope Property Management Limited | Professional & scientific | 2015 |
| Inside OUT Property Repairs Ltd | Construction | 2012 |
| Insight 24 Ltd | Professional & scientific | 2023 |
| Insight Biopharma Consultancy Limited | Professional & scientific | 2023 |
| Insight Finance Services Ltd | Professional & scientific | 2023 |
| Insight Marketing (Ribchester) Limited | Real estate | 2002 |
| Insight Property NW Limited | Professional & scientific | 2026 |
| Insightaudit Group Ltd | Professional & scientific | 2024 |
| Insightresolve Ltd | Professional & scientific | 2026 |
| Insignia Kitchens & Bedrooms Limited | Wholesale & retail | 2008 |