| Inkden Tattoo Ltd | Arts & recreation | 2023 |
| Inlon Distribution Limited | Wholesale & retail | 2015 |
| Inmosystem UK Ltd | Extraterritorial | 2016 |
| Inncellar Equipment Ltd | Professional & scientific | 2023 |
| INNOV8 Utilities Limited | Professional & scientific | 2025 |
| Innova - Finance and AI Ltd | Financial services | 2024 |
| Innovative Incentive Ltd | Manufacturing | 2025 |
| Innovs Property Ltd | Real estate | 2025 |
| Innspired Leisure and Hospitality Ltd | Hospitality | 2025 |
| Inntrepid Ltd | Hospitality | 2025 |
| Inoventors Limited | Extraterritorial | 1963 |
| INP Leisure Limited | Arts & recreation | 2021 |
| Insel Projekte Ltd | Wholesale & retail | 2025 |
| Insight (Fylde) Limited | Health & social care | 2013 |
| Inskip Installations Ltd | Construction | 2011 |
| Inspired Health and Well-Being Centre Ltd | Administrative & support | 2019 |
| Inspired Mental Health Empowerment Centre CIC | Health & social care | 2023 |
| Instantflirts Ltd | Information & communication | 2020 |
| Institute of Retail Distribution Management | Education | 1962 |
| Insul-Eight Contracts Limited | Construction | 2011 |
| Insulated Roofing Ltd | Construction | 2024 |
| Intalinks Ltd | Professional & scientific | 2018 |
| Intasun Holdings Ltd | Arts & recreation | 2016 |
| Integral Consultancy 365 Ltd | Professional & scientific | 2016 |
| Integral Technical Systems Ltd | Information & communication | 2009 |
| Integrated Assessments Ltd | Health & social care | 2024 |
| Integrated Therapeutic Services Ltd | Health & social care | 2025 |
| Intelligent Revenue Management Limited | Hospitality | 2013 |
| Intellis D&S Ltd | Information & communication | 2019 |
| Inter Car Cleaning (NW) Limited | Wholesale & retail | 2013 |
| Interlansys Ltd | Professional & scientific | 2019 |
| International App Company Limited | Professional & scientific | 2022 |
| International Connections Group Holdings PLC | Financial services | 2024 |
| International Connections Group Ltd | Professional & scientific | 2013 |
| International Food Store Central Drive Limited | Wholesale & retail | 2024 |
| International Supermarket 2 Limited | Wholesale & retail | 2025 |
| International Wholesalers Supplies Ltd | Wholesale & retail | 2025 |
| Interstella Limited | Information & communication | 2022 |
| Inutox Limited | Administrative & support | 2016 |
| Investing Earning Living Ltd | Education | 2020 |
| Investment Empire Limited | Construction | 2024 |
| Investworth Holdings Ltd | Real estate | 2019 |
| Investworth Homes Ltd | Professional & scientific | 2019 |
| Investworth Property Ltd | Real estate | 2019 |
| Investworth Renovations Ltd | Construction | 2019 |
| Invicta Management Consulting Ltd | Information & communication | 2022 |
| Inville Limited | Hospitality | 2001 |
| Ionut C Barber Ltd | Other services | 2026 |
| Ionut Mihnea Ltd | Health & social care | 2025 |
| Iotabay Ltd | Transport & logistics | 2020 |
| Ipitek Ltd | Information & communication | 2020 |
| Iquality Limited | Information & communication | 2017 |
| IR Carpentry & Joinery Ltd | Construction | 2023 |
| Iram Ltd | Wholesale & retail | 2024 |
| Iramco Projects Ltd | Professional & scientific | 2024 |
| IRINA777 Limited | Health & social care | 2014 |
| Irwin Offshore Inspection Services Limited | Mining & quarrying | 2019 |
| Isabella Software Solutions Limited | Information & communication | 2021 |
| Iseon Limited | Real estate | 2021 |
| Isla Nublar Holdings Ltd | Financial services | 2021 |
| Island Kelly Limited | Wholesale & retail | 2025 |
| ISM Developments Ltd | Wholesale & retail | 2025 |
| Isoft Testing Solutions Ltd | Information & communication | 2017 |
| Ison Software Consulting Services Limited | Information & communication | 2015 |
| Istanbul Barber Blackpool Ltd | Other services | 2024 |
| Istanbul Kebab Blackpool Ltd | Hospitality | 2025 |
| IT IS Business Consultancy Limited | Administrative & support | 2026 |
| IT Laboratory Ltd | Administrative & support | 2014 |
| IT Systems & Telecoms Consultancy Services Ltd | Information & communication | 2020 |
| Italian Star Bispham Ltd | Hospitality | 2026 |
| Italio Express Limited | Hospitality | 2014 |
| Itechsquad Ltd | Other services | 2022 |
| Iterative IT Limited | Information & communication | 2010 |
| Ithaca Financial Planning Limited | Professional & scientific | 2021 |
| Ithaca Wealth Management Group Limited | Financial services | 2021 |
| ITK Install Ltd | Construction | 2022 |
| Itmetis Limited | Information & communication | 2017 |
| Ivandale Limited | Manufacturing | 2018 |
| IVANHOE13 Ltd | Hospitality | 2025 |
| Ivory Dental Care Limited | Health & social care | 2008 |
| Iworks Consulting Ltd | Other services | 2020 |
| IX Forum Ltd | Education | 2024 |
| Iyco Yachting Ltd | Extraterritorial | 2024 |
| IZ 98 Limited | Professional & scientific | 2025 |
| Izzi-B Ltd | Arts & recreation | 2018 |
| J & C (Joinery and Construction) Limited | Manufacturing | 2010 |
| J & D Fish Limited | Hospitality | 2025 |
| J & H Apartments Limited | Hospitality | 2026 |
| J & J Decorating Services Ltd | Construction | 2021 |
| J & J Elite Developments Ltd | Construction | 2025 |
| J & K Leisure Ltd | Hospitality | 2016 |
| J & P Properties Blackpool Ltd | Hospitality | 2025 |
| J & R Bradshaw Plumbing & Drainage Limited | | 1998 |
| J & R Chip Shop Ltd | Hospitality | 2026 |
| J & S Properties (North West) Limited | Real estate | 2008 |
| J & T Holdings Limited | Financial services | 2017 |
| J & T Productions (Blackpool) Limited | Arts & recreation | 2015 |
| J & T Trading Limited | Financial services | 2018 |
| J a Gorton Investments Ltd | Real estate | 2020 |
| J a Howells Consulting Ltd | Professional & scientific | 2014 |