| Industrial Painters Ltd | Administrative & support | 2020 |
| Industrial Scaffolding Limited | Wholesale & retail | 1974 |
| Industrial Services Group Ltd | Wholesale & retail | 1989 |
| Industrial Suppliers UK Ltd | Manufacturing | 2020 |
| Industrial Training Services (UK) Limited | Education | 1994 |
| Industry Approved Ltd | Professional & scientific | 2019 |
| Industry Media Consulting Limited | Professional & scientific | 2023 |
| Indy YUM Limited | Hospitality | 2020 |
| Inedge Ltd | Wholesale & retail | 2025 |
| Ineeporsports Ltd | Wholesale & retail | 2021 |
| Ineffable Spa Ltd | Other services | 2019 |
| Inelon Holdings Ltd | Information & communication | 2018 |
| Inens Investments Limited | Extraterritorial | 1961 |
| Inest Homes Ltd | Real estate | 2025 |
| Inet Logistics Ltd | Transport & logistics | 2018 |
| Inetyears Limited | Information & communication | 2015 |
| Ineuk Ltd | Wholesale & retail | 2020 |
| Inex London Ltd | Wholesale & retail | 2015 |
| Infarm Technologies Limited | Agriculture & fishing | 2023 |
| Infatech Engineering Ltd | Professional & scientific | 2024 |
| Inference Magazine Ltd | Information & communication | 2025 |
| Infermedia Ltd | Information & communication | 2025 |
| Inferno Trading Limited | Water & waste | 2023 |
| Infimo Ltd | Financial services | 2019 |
| Infinet Solutions Limited | Wholesale & retail | 2024 |
| Infiniaura Limited | Wholesale & retail | 2025 |
| Infinireuse Ltd | Manufacturing | 2025 |
| Infinitas International Ltd | Professional & scientific | 2014 |
| Infinite Bytes Stream Ltd | Information & communication | 2024 |
| Infinite Financial Insight Ltd | Professional & scientific | 2024 |
| Infinite Heat Ltd | Wholesale & retail | 2020 |
| Infinite Horizon Consulting Ltd | Professional & scientific | 2025 |
| Infinite Life Insure Ltd | Financial services | 2023 |
| Infinite Media Success PC | | 2017 |
| Infinite Outdoor Products Ltd | Wholesale & retail | 2024 |
| Infinite Solutions (Cardiff) Limited | Construction | 2019 |
| Infiniti Healthcare Ltd | Health & social care | 2013 |
| Infiniti Partners Limited | Financial services | 2010 |
| Infiniti Recruitment Ltd | Administrative & support | 2018 |
| Infinitum F7 Limited | Wholesale & retail | 2022 |
| Infinitus Professional Services Ltd | Professional & scientific | 2023 |
| Infinity Blackwood Ltd | Wholesale & retail | 2018 |
| Infinity Business Advancement Systems Ltd. | Information & communication | 2012 |
| Infinity Consultants (IT) Ltd. | Information & communication | 2015 |
| Infinity Cwmbran Ltd | Wholesale & retail | 2018 |
| Infinity Dawn Ltd. | Wholesale & retail | 2025 |
| Infinity Design Studio Ltd | Wholesale & retail | 2021 |
| Infinity E-Commerce Ltd | Wholesale & retail | 2025 |
| Infinity Global Group Limited | Real estate | 2017 |
| Infinity Healthcare Ltd | Health & social care | 2025 |
| Infinity Investment Holdings Limited | Real estate | 2016 |
| Infinity Kingdom Healthcare Limited | Health & social care | 2020 |
| Infinity Moon Limited | Health & social care | 2023 |
| Infinity Nails and Beauty Salon Limited | Other services | 2020 |
| Infinity National Ltd | Construction | 2019 |
| Infinity Occasions Limited | Hospitality | 2024 |
| Infinity Plymouth Ltd | Wholesale & retail | 2018 |
| Infinity Point Ltd | Information & communication | 2019 |
| Infinity Technologies Corporation Ltd | Information & communication | 2018 |
| Infinity UK Private Limited | Real estate | 2022 |
| Infinityintelligence Ltd | Information & communication | 2025 |
| Infinium Digital Ltd | Wholesale & retail | 2025 |
| Infinty Services Ltd | Construction | 2014 |
| Inflatable Bliss Limited | Arts & recreation | 2025 |
| INFLATE2SKATE Ltd | Administrative & support | 2023 |
| Inflowen Ltd | Information & communication | 2025 |
| Influence Network Ltd | Information & communication | 2017 |
| Influencer Growth Services Ltd | Professional & scientific | 2025 |
| Influencer Swap Limited | Professional & scientific | 2020 |
| Influent Private Markets Limited | Financial services | 2023 |
| Influnique Ltd | Professional & scientific | 2018 |
| Infogovern Ltd | Information & communication | 2019 |
| Infolast Ltd | Wholesale & retail | 2025 |
| Infopro Services Limited | Information & communication | 2025 |
| Inform Active Limited | Wholesale & retail | 2024 |
| Inform Corporation Limited | Information & communication | 1992 |
| Informa Expo Ltd | Wholesale & retail | 2022 |
| Informatech Solutions Ltd | Information & communication | 2025 |
| Informatech Training Ltd | Information & communication | 2018 |
| Informatics Education UK Limited | Education | 2006 |
| Information Technical Support Ltd | Information & communication | 2019 |
| Informative Services Limited | Professional & scientific | 2021 |
| Inforstrat Consulting Ltd | Information & communication | 2016 |
| Inforza Solutions Ltd | Information & communication | 2026 |
| Infoseny Ltd | Information & communication | 2025 |
| Infosphere Limited | Professional & scientific | 2000 |
| Infospot Limited | Information & communication | 2004 |
| Infotec Projects Ltd | Information & communication | 2019 |
| Infotech Consultancy Services Limited | Information & communication | 2007 |
| Infrarisk Ltd | Information & communication | 2017 |
| Infravectra Ltd | Information & communication | 2026 |
| ING Store Ltd | Wholesale & retail | 2025 |
| Ingame Services Ltd | Other services | 2019 |
| Ingeborg VD Heuvel Access FND Ltd | Wholesale & retail | 2025 |
| Ingen Media Limited | Professional & scientific | 2020 |
| Ingen Property Limited | Real estate | 2020 |
| Ingenium AI Group Ltd | Information & communication | 2026 |
| Ingenium Designs Limited | Manufacturing | 2025 |
| Ingenium Insight Limited | Professional & scientific | 2009 |
| Ingenium Services Limited | Professional & scientific | 2007 |