| Innovation DT Ltd | Wholesale & retail | 2020 |
| INNOVATION4ALL Ltd | Real estate | 2025 |
| Innovative Accounts Ltd | Professional & scientific | 2016 |
| Innovative Brains Limited | Professional & scientific | 2016 |
| Innovative Contractors Limited | Construction | 2024 |
| Innovative Hospitality Ltd | Administrative & support | 2022 |
| Innovative Marketing Management Limited | Information & communication | 2013 |
| Innovative Mart Ltd | Wholesale & retail | 2023 |
| Innovative Realities Ltd | Information & communication | 2015 |
| Innovative Systems Limited | Information & communication | 2021 |
| Innovative Team Solutions Ltd | Information & communication | 2011 |
| Innovative Technology Solutions Pro C.I.C. | Information & communication | 2016 |
| Innovax Ltd | Wholesale & retail | 2026 |
| Innovbiz Limited | Real estate | 2015 |
| Inns of London Ltd | Hospitality | 2024 |
| Innsight Advisors Ltd | Professional & scientific | 2025 |
| Inntech World Ltd | Information & communication | 2022 |
| Inovexa Limited | Information & communication | 2024 |
| Inovexia Limited | Wholesale & retail | 2021 |
| Inpsych Properties Limited | Real estate | 2023 |
| Insa Connect Ltd | Real estate | 2023 |
| Insaf Services Ltd | Professional & scientific | 2015 |
| Inscope Consultancy Ltd | Information & communication | 2016 |
| Inseptio Services Ltd | Information & communication | 2015 |
| Inside Homes Estate Agents UK Limited | Real estate | 2016 |
| Insidelife Ltd | Other services | 2020 |
| Insider Academy Limited | Other services | 2017 |
| Insight Education Academy Ltd | Education | 2026 |
| Insight Ghrf Consultancy Ltd | Information & communication | 2023 |
| Insightful Education Ltd | Real estate | 2023 |
| Insin Skills Carpentry & Joinery Ltd | Construction | 2019 |
| Insipid Oak Estates Limited | Real estate | 2021 |
| Insofto Ltd | Wholesale & retail | 2025 |
| Inspire Day Nurseries Limited | Education | 2010 |
| Inspire Social Care Ltd | Health & social care | 2018 |
| Inspire Wholesale Limited | Wholesale & retail | 2010 |
| Inspirebiz Ltd | Information & communication | 2025 |
| Inspired Catering Solutions Ltd | Hospitality | 2017 |
| Inspirexspace Ltd | Real estate | 2024 |
| Instacom Ltd | Information & communication | 2014 |
| Instal Group Ltd | Construction | 2019 |
| Installutions Limited | Construction | 2019 |
| Instant Domains Ukeig | | 2014 |
| Instant Dry-Lining Limited | Construction | 2020 |
| Instant Freight Limited | Transport & logistics | 2017 |
| Instant Holdings Ltd | Professional & scientific | 2014 |
| Instant Medical Services Limited | Health & social care | 2025 |
| Instant Network Solution Limited | Information & communication | 2012 |
| Instant Properties MK Limited | Real estate | 2019 |
| Instant Property Limited | Real estate | 2014 |
| Instant Taxi Services Limited | Transport & logistics | 2024 |
| Instant Technology Centre Ltd | Wholesale & retail | 2015 |
| Instructional Design Systems Ltd | Information & communication | 2023 |
| Insulate Smart Ltd | Construction | 2025 |
| Insulations and Installations Ltd | Construction | 2019 |
| Insure NOW UK Ltd | Wholesale & retail | 2025 |
| Insutherm Ltd | Construction | 2022 |
| Insyn Ltd | Wholesale & retail | 2026 |
| INT Admission Service Ltd | Professional & scientific | 2022 |
| INT Communications Ltd | Information & communication | 2021 |
| Int-Elligence Tech Solutions Limited | Information & communication | 2024 |
| Int-Renovations Ltd | Construction | 2019 |
| INT. Superstore Ltd | Wholesale & retail | 2013 |
| Intaz and Co UK Ltd | Wholesale & retail | 2021 |
| Intbusiness Limited | Education | 2013 |
| INTEG360 Ltd | Professional & scientific | 2025 |
| Integrated Finance Solutions Ltd | Professional & scientific | 2025 |
| Integrated Network Solutions Ltd | Information & communication | 2018 |
| Integrated Sales Systems Limited | Administrative & support | 2019 |
| Integrative Psychiatry London Ltd | Health & social care | 2017 |
| Integritas London Limited | Professional & scientific | 2025 |
| Integritas NB Limited | Real estate | 2020 |
| Integritas SDQ Ltd | Real estate | 2020 |
| Integritas SS Limited | Real estate | 2020 |
| Integritas US Limited | Real estate | 2020 |
| Intel Port Ltd | Wholesale & retail | 2023 |
| Intelect Trading (UK) Limited | Professional & scientific | 2009 |
| Intellect Marketing Ltd | Professional & scientific | 2025 |
| Intellect Security and FM Services Ltd | Administrative & support | 2024 |
| Intelli Science Limited | Professional & scientific | 2025 |
| Intelligent Applications Ltd | Professional & scientific | 2026 |
| Intelligent Financial Analytics Limited | Professional & scientific | 2013 |
| Intelligent Trade Limited | Wholesale & retail | 2012 |
| Intelligentai World Ltd | Information & communication | 2024 |
| Intellinapse Ltd | Information & communication | 2025 |
| Intellitech Creations Ltd | Information & communication | 2024 |
| Intelliversetech Ltd | Information & communication | 2025 |
| Intellivisim Limited | Construction | 2023 |
| Intelliworks Technology Services Limited | Information & communication | 2019 |
| Intem Technology Solutions Ltd. | Wholesale & retail | 2020 |
| Inter Cologne Ltd | Wholesale & retail | 2025 |
| Inter Master Ltd | Wholesale & retail | 2011 |
| Inter-Comp Ltd | Information & communication | 1995 |
| Inter-Spares (UK) Limited | Wholesale & retail | 2002 |
| Interactive Phonics Limited | Education | 2023 |
| Interaxis UK Limited | Professional & scientific | 2025 |
| Interbiz Medical Limited | Health & social care | 2015 |
| Intercity Furniture Ltd. | Wholesale & retail | 2024 |
| Intercoachtravel Limited | Transport & logistics | 2023 |
| Intercon Vista Limited | Professional & scientific | 2021 |