| Indulgence Catering Services Limited | Hospitality | 2024 |
| Indulgent Nights Ltd | Real estate | 2023 |
| Induro Ltd | Construction | 2021 |
| Indus Route Limited | Wholesale & retail | 2024 |
| Indus Talkies Limited | Information & communication | 2016 |
| Industria Medica Limited | Health & social care | 1999 |
| Industria Verde Search Ltd | Administrative & support | 2024 |
| Industrial & Commercial Heating (Holdings) Limited | Professional & scientific | 2007 |
| Industrial Air Spares Ltd | Wholesale & retail | 2026 |
| Industrial and Fluid Power Products Limited | Wholesale & retail | 2024 |
| Industrial Boiler House Training and Engineering Consultants Ltd | Professional & scientific | 2019 |
| Industrial Cleaning Machinery (UK) Ltd | Manufacturing | 2011 |
| Industrial Cleaning Team Ltd | Extraterritorial | 2024 |
| Industrial Fibres (Dewsbury) Limited | Administrative & support | 1967 |
| Industrial Fibres Limited | Administrative & support | 1964 |
| Industrial Plastic Supplies Limited | Manufacturing | 1985 |
| Industruct Limited | Real estate | 2023 |
| Indygo Solutions Ltd | Information & communication | 2012 |
| Inergis Limited | Professional & scientific | 2013 |
| Inet Solutions UK Ltd | Information & communication | 2009 |
| Ineva Limited | Wholesale & retail | 2024 |
| Inexcess Limited | Administrative & support | 1987 |
| Inexhaustible Power Ltd | Professional & scientific | 2025 |
| Infaant Ltd | Wholesale & retail | 2021 |
| Infection Control Systems Ltd | Administrative & support | 2009 |
| Inferno Electronics Limited | Wholesale & retail | 2020 |
| Inferno Spice Ltd | Hospitality | 2025 |
| Infigo Media Group Limited | Information & communication | 2019 |
| Infinaeon AI Media Group Ltd | Information & communication | 2025 |
| Infiniai Ltd | Administrative & support | 2026 |
| Infinit Software Services Limited | Information & communication | 2017 |
| Infinitask Ltd | Manufacturing | 2023 |
| Infinite Bespoke Interiors Limited | Professional & scientific | 2017 |
| Infinite BIM Limited | Professional & scientific | 2005 |
| Infinite Fortune Properties Ltd | Real estate | 2018 |
| Infinite Gene Pool Ltd | Information & communication | 2011 |
| Infinite Gleam Ltd | Wholesale & retail | 2025 |
| Infinite Illusion Ltd | Administrative & support | 2024 |
| Infinite Mindset Ltd | Professional & scientific | 2025 |
| Infinite Playground X Limited | Information & communication | 2019 |
| Infinite Resource 2014 Limited | Construction | 2014 |
| Infiniti Vision Holding Limited | Financial services | 2024 |
| Infiniti Vision Investments Limited | Financial services | 2024 |
| Infiniti Vision Limited | Health & social care | 2019 |
| Infinitum IT Solutions Ltd | Information & communication | 2016 |
| Infinitus Lettings Ltd | Real estate | 2019 |
| Infinity & Co Limited | Wholesale & retail | 2014 |
| Infinity Autosmart Tech Ltd | Wholesale & retail | 2025 |
| Infinity Barbers Holding Ltd | Financial services | 2024 |
| Infinity Barbers Limited | Other services | 2019 |
| Infinity Barbers Pudsey Limited | Other services | 2021 |
| Infinity Barbers Roundhay Limited | Other services | 2019 |
| Infinity Construction Enterprise Limited | Construction | 2021 |
| Infinity Float UK Ltd | Other services | 2019 |
| Infinity Homes & Projects Limited | Construction | 2016 |
| Infinity Innovations Limited | Wholesale & retail | 2012 |
| Infinity Legal Solicitors Limited | Extraterritorial | 2020 |
| Infinity Matrix Ltd | Information & communication | 2021 |
| Infinity Power Ltd | Extraterritorial | 2024 |
| Infinity Project Planning Ltd | Professional & scientific | 2025 |
| Infinity Property Maintenance Limited | Construction | 2015 |
| Infinity Savings & Investment Company Ltd | Hospitality | 2023 |
| Infinity Supplements Ltd | Wholesale & retail | 2024 |
| Infinity TAN Ltd | Other services | 2026 |
| Infinity Theory Limited | Information & communication | 2025 |
| Infinity Trade Group Ltd | Wholesale & retail | 2020 |
| Infitech Consultancy Ltd | Information & communication | 2023 |
| Influence Link Limited | Professional & scientific | 2025 |
| Influenzd Ltd | Information & communication | 2025 |
| Influnity Limited | Information & communication | 2024 |
| Influx Search Ltd | Administrative & support | 2023 |
| Infoclass Consulting Limited | Information & communication | 2018 |
| Infodream Limited | Information & communication | 2007 |
| Infohub Consult Limited | Administrative & support | 2024 |
| Infonest Digital Ltd | Information & communication | 2024 |
| Inform Construction Consultants Ltd | Construction | 2020 |
| Information Change Organisation Limited | Professional & scientific | 1994 |
| Information Network Services Ltd. | Information & communication | 1997 |
| Information Security Manager Limited | Information & communication | 2016 |
| Informatix Data Solutions Limited | Information & communication | 2018 |
| INFOSEC360 Ltd | Information & communication | 2014 |
| Infoserve Limited | Professional & scientific | 1999 |
| Infoserve.Com Limited | Information & communication | 2001 |
| Infota PVT Ltd | Information & communication | 2022 |
| Infra Green Limited | Manufacturing | 2013 |
| Infrastructure Delivery Partners Limited | Construction | 2026 |
| Infrastructure Group Limited | Construction | 2018 |
| Infrastructure Networks U.K. Limited | Information & communication | 2023 |
| Infusion Products Limited | Manufacturing | 2019 |
| Infusion Software Development Limited | Information & communication | 2020 |
| Infusionize Ltd | Wholesale & retail | 2024 |
| Infyshine Technologies Limited | Information & communication | 2025 |
| Infytera Solutions Limited | Information & communication | 2022 |
| ING Transport Limited | Transport & logistics | 2025 |
| Inga Narubina Healthcare Limited | Health & social care | 2020 |
| Ingear Holiday Clubs Limited | Education | 2023 |
| Ingenaium Ltd | Information & communication | 2025 |
| Ingenico (UK) Limited | Manufacturing | 1987 |
| Ingenieus Limited | Administrative & support | 2018 |
| Ingenious Legal Limited | Professional & scientific | 2018 |