| IE Siddy Ltd | Real estate | 2021 |
| Iesis (Ambra Vale) Limited | Real estate | 2008 |
| Iesis (Braggs Lane) Limited | Construction | 2015 |
| Iesis (Jacobs Wells Road) Limited | Construction | 2012 |
| Iesis Consult Limited | Professional & scientific | 2019 |
| Iesis Creative Productions Ltd | Administrative & support | 2017 |
| Iesis IMS Ltd. | Real estate | 2013 |
| Iesis Lettings & Management Limited | Real estate | 2011 |
| Iesis Limited | Professional & scientific | 2008 |
| Iesis Urban Spaces Limited | Construction | 2017 |
| Iestyn Keyes Limited | Information & communication | 2026 |
| IF Lending Servicing Limited | Information & communication | 2019 |
| Iffley Consulting Ltd | Financial services | 2012 |
| Ignite Sport & Physical Education Limited | Education | 2024 |
| Ignition Strategic Design Ltd. | Administrative & support | 1996 |
| Ignoble Illustrations Limited | Wholesale & retail | 2023 |
| IHM Recruitment Limited | Professional & scientific | 1983 |
| IKON1 Limited | Wholesale & retail | 2017 |
| Iland Consulting Limited | Professional & scientific | 2018 |
| Ilean Limited | Wholesale & retail | 2010 |
| Illuminare Consulting Ltd | Professional & scientific | 2018 |
| Illyrian Entertainment Ltd | Information & communication | 2025 |
| IMA Transport Planning Limited | Professional & scientific | 2001 |
| Image Craft Productions Ltd | Professional & scientific | 2016 |
| Imagicians Television Ltd | Information & communication | 2019 |
| Imagiro Ltd | Information & communication | 2023 |
| Imogen Lucie Ltd | Other services | 2021 |
| Imonboard Ltd | Professional & scientific | 2026 |
| Imoore Ltd | Construction | 2020 |
| Impact Holdings Ltd | Professional & scientific | 2024 |
| Imperial Consulting Limited | Information & communication | 2013 |
| Imperial Gardens and Driveways Ltd | Construction | 2025 |
| Imperial Household Staff Limited | Administrative & support | 2010 |
| Imperial Preservation Limited | Construction | 2005 |
| Imperidox Limited | Information & communication | 2025 |
| Imperium Education Limited | Education | 2017 |
| Imperium Electrics Ltd | Energy | 2019 |
| Impulsive Audio Ltd | Administrative & support | 2025 |
| IN VIA Lactea Catering Ltd | Hospitality | 2026 |
| Inazone Ltd | Administrative & support | 2002 |
| Inca Aviation Ltd | Transport & logistics | 2026 |
| Inconel Networks Limited | Information & communication | 2011 |
| Incyan Limited | Information & communication | 2009 |
| Incygames Ltd | Information & communication | 2016 |
| Indeex Ltd | Construction | 2018 |
| Independent Business Alliance Ltd | Other services | 2026 |
| Independent EYE Limited | Professional & scientific | 2015 |
| Independent Health Group Limited | Health & social care | 2004 |
| Independent Spirit of Bath Limited | Wholesale & retail | 2012 |
| Independent Vascular Diagnostics Limited | Health & social care | 2005 |
| Indian Tent Events Ltd | Manufacturing | 2025 |
| Indigo-Yachts Limited | Manufacturing | 2018 |
| Industria Automotive Ltd | Wholesale & retail | 2025 |
| Infinite Hype Ltd | Professional & scientific | 2026 |
| Infinite Jest Ltd | Information & communication | 2013 |
| Infinite Jest Theatre Company Ltd | Education | 2020 |
| Influxly Ltd | Other services | 2025 |
| Infomode Holdings Limited | Professional & scientific | 2023 |
| Infomode Limited | Professional & scientific | 2010 |
| Information Technology Infrastructure Limited | Information & communication | 2000 |
| Informed Choice (South West) Limited | Financial services | 1983 |
| Informed Risk Decisions Ltd | Administrative & support | 2015 |
| Informu Solutions Limited | Information & communication | 2009 |
| Infosec Consultancy Limited | Information & communication | 2017 |
| Infracare Partners Limited | Construction | 2025 |
| Ingenious Frame! Limited | Professional & scientific | 2024 |
| Ingeniumai Limited | Professional & scientific | 2022 |
| Ingram Hill Racing Limited | Arts & recreation | 2021 |
| Initus Data Ltd | Information & communication | 2020 |
| INK and Snail Limited | Arts & recreation | 2023 |
| INK Copywriters Ltd | Professional & scientific | 2005 |
| Inkcap Design Limited | Professional & scientific | 2011 |
| Inkunzi Property Investments Ltd | Real estate | 2020 |
| Inkwazi Consulting Ltd | Professional & scientific | 2026 |
| Inkwell Agency Limited | Information & communication | 2017 |
| Inlight Yoga Limited | Arts & recreation | 2024 |
| Inline Construction Ltd | Construction | 2022 |
| Inmor Ltd | Financial services | 2023 |
| Inn Freshford Ltd | Hospitality | 2016 |
| Innate Health Chiropractic Ltd | Health & social care | 2021 |
| Innchange Limited | Extraterritorial | 2013 |
| Inner Source Limited | Education | 2026 |
| Innervision Services Ltd | Professional & scientific | 2005 |
| Inni Corporation Limited | Professional & scientific | 2016 |
| Innotive Diagnostics Limited | Professional & scientific | 2019 |
| INNOV8 Ecommerce Limited | Wholesale & retail | 2025 |
| Innovar Partners Limited | Professional & scientific | 2025 |
| Innovation Advantage Limited | Professional & scientific | 2002 |
| Innovation Mapping Limited | Professional & scientific | 2013 |
| Innovative Construction Services Ltd | Construction | 2024 |
| Innsyn Ltd | Professional & scientific | 2018 |
| Inreach Health Limited | Health & social care | 2014 |
| Insane in the Rain Ltd | Wholesale & retail | 2016 |
| Inside OUT Mastery Ltd | Information & communication | 2020 |
| Inside OUT Property Renovations Ltd | Construction | 2022 |
| Insight CF Limited | Financial services | 2022 |
| Insight Developments Bath Ltd | Construction | 2015 |
| Insight Media UK Limited | Information & communication | 2002 |
| Insight Nexus Limited | Information & communication | 2020 |
| Insight-Space Studio Limited | Professional & scientific | 2025 |