| Imvelo Ltd. | Professional & scientific | 2015 |
| IN & OUT Stores Ltd | Wholesale & retail | 2024 |
| IN Green Fields Limited | Hospitality | 2023 |
| IN Your Own Corner Ltd | Information & communication | 2025 |
| In-House Air Conditioning Ltd | Manufacturing | 2016 |
| In.Solve Limited | Extraterritorial | 2020 |
| IN2LOCKS Newcastle Limited | Administrative & support | 2017 |
| Incendia (Safety Solutions) Ltd | Professional & scientific | 2012 |
| Inceptavia Ltd | Professional & scientific | 2025 |
| Inchbroom Capital Limited | Real estate | 2025 |
| Incident Rays Ltd | Information & communication | 2013 |
| Incidental Group Limited | Financial services | 2025 |
| Incidental Ltd | Wholesale & retail | 2019 |
| Incidental Training Ltd | Education | 2021 |
| Inclusion Hair Network CIC | Education | 2022 |
| Inclusive Horizon CIC | Education | 2026 |
| Incommon CIC | Arts & recreation | 2021 |
| Incorporate Consulting Limited | Professional & scientific | 2009 |
| Incorporated Association of Cost and Industrial Accountants Limited(The) | Other services | 1937 |
| Incorporationservices Limited | Professional & scientific | 2010 |
| Incrementum North East Limited | Administrative & support | 2021 |
| Indarth Partners LLP | | 2007 |
| Independent Funeral Planning Services Ltd | Other services | 2021 |
| Independent Software Development Limited | Information & communication | 2003 |
| Independent Tattoo Artists Limited | Administrative & support | 2015 |
| Independent Utility Advice Ltd | Administrative & support | 2017 |
| Independent-Events.Com Ltd | Other services | 2008 |
| Index Music Ltd | Information & communication | 2024 |
| Indi-Bars Ltd | Wholesale & retail | 2018 |
| India Vegan Ltd | Hospitality | 2019 |
| Indian Kings Walk 1 Limited | Real estate | 2002 |
| Indian Snack Lunch Box Ltd | Hospitality | 2018 |
| Indicatrix Crystallography Limited | Professional & scientific | 2019 |
| Indie People Ltd | Professional & scientific | 2025 |
| Indigo A.G.A. Limited | Administrative & support | 2014 |
| Indigo Digital Limited | Extraterritorial | 2016 |
| Indigo Puzzles Limited | Wholesale & retail | 2023 |
| Indigo Stays Ltd | Hospitality | 2025 |
| Indigo Steel UK Ltd | Administrative & support | 2012 |
| Indo Group Limited | Financial services | 2025 |
| Indo Investments Limited | Real estate | 2024 |
| Indo Properties Limited | Real estate | 2021 |
| Indo Property Consultants Ltd | Professional & scientific | 2018 |
| Indus Legacy Ltd. | Education | 2026 |
| Industrial Business Group Limited | Financial services | 2018 |
| Industrial Energy Services Limited | Manufacturing | 1983 |
| Industrial GAS Services (NE) Limited | Construction | 2019 |
| Industrial Patternmakers Limited | Manufacturing | 2001 |
| Industrial Roofing Services (North East) Limited | Construction | 2015 |
| Industrial Turbine Company (UK) Limited | Manufacturing | 2014 |
| Ineffable Solutions Ltd | Wholesale & retail | 2023 |
| Inertia Projects Limited | Real estate | 2012 |
| Inetsoft Limited | Information & communication | 2002 |
| Infiline Limited | Wholesale & retail | 2024 |
| Infinite Brilliance Limited | Other services | 2020 |
| Infinite Pilates Ltd | Arts & recreation | 2021 |
| Infiniti Food (Manufacturing) Ltd | Manufacturing | 2016 |
| Infinitree Studios Ltd | Wholesale & retail | 2023 |
| Infinity Accommodation Ltd | Real estate | 2022 |
| Infinity Car Care (NE) Ltd | Wholesale & retail | 2023 |
| Infinity Enterprises MB & SBK Ltd | Hospitality | 2017 |
| Infinity Rentals U K Limited | Real estate | 2025 |
| Infinity Scale Solutions Ltd | Information & communication | 2022 |
| Infinix NCL Limited | Hospitality | 2023 |
| Influx Properties Limited | Real estate | 2024 |
| Information Managers Ltd | Professional & scientific | 2011 |
| Information Works London Limited | Administrative & support | 2010 |
| Informatly Limited | Information & communication | 2020 |
| Infotel UK Consulting Ltd | Information & communication | 2015 |
| Infrasound Limited | Administrative & support | 2026 |
| Infrastructure Investors Defence Housing (Bristol) Limited | Administrative & support | 2000 |
| Infrastructure North Limited | Extraterritorial | 2011 |
| Infrazen Ltd | Information & communication | 2023 |
| Infronix Ltd | Information & communication | 2025 |
| Infused Sounds Ltd | Arts & recreation | 2025 |
| Infusion Master Limited | Manufacturing | 2024 |
| Infusion Newcastle Ltd | Hospitality | 2018 |
| INGALO4 Limited | Professional & scientific | 2016 |
| Ingleby Court Management Limited | Administrative & support | 2001 |
| Inglewood Care Home Ltd | Health & social care | 2017 |
| Ingram a V Limited | Administrative & support | 2015 |
| Ingram Trading Ltd | Health & social care | 2025 |
| Ingsport Racing Limited | Administrative & support | 2014 |
| Initial GP1 Limited | Administrative & support | 2012 |
| INK Clan Nation Limited | Manufacturing | 2024 |
| Inkbell Limited | Construction | 2024 |
| Inkcrease Print Ltd | Manufacturing | 2020 |
| Inked Image Ltd | Manufacturing | 2026 |
| Inkspot Science Limited | Information & communication | 2008 |
| Inlearn L & D Services Ltd | Education | 2013 |
| Inn Collection (Bassenthwaite) Limited | Extraterritorial | 2019 |
| Inn Collection (Bowness) Limited | Extraterritorial | 2014 |
| Inn Collection (Glenridding) Limited | Extraterritorial | 2021 |
| Inn Collection (Grasmere) Limited | Extraterritorial | 2006 |
| Inn Collection (Helmsley) Limited | Extraterritorial | 2019 |
| Inn Collection (Knaresborough) Limited | Hospitality | 2020 |
| Inn Collection (Llandudno) Limited | Extraterritorial | 2022 |
| Inn Collection (Lytham) Limited | Hospitality | 2020 |
| Inn Collection (Morecambe) Limited | Extraterritorial | 2022 |
| Inn Collection (Northallerton) Limited | Hospitality | 2019 |