| Infinity Academic Services Ltd | Education | 2026 |
| Infinity Carpentry and Joinery Ltd | Manufacturing | 2021 |
| Infinity Coffee Ltd | Hospitality | 2025 |
| Infinity Dental LAB Ltd | Other services | 2023 |
| Infinity Energy Services Limited | Construction | 2011 |
| Infinity Facade Consultants Ltd | Professional & scientific | 2020 |
| Infinity Homes (Southern) Ltd | Real estate | 2023 |
| Infinity Property (South) Ltd | Real estate | 2025 |
| Infinity Property Investment Portfolio Limited | Real estate | 2017 |
| Infinity Services & Solutions Ltd | Real estate | 2021 |
| Inflata Eastleigh Ltd | Arts & recreation | 2022 |
| Inflataplanet Ltd | Arts & recreation | 2021 |
| Influenced.Me Ltd | Wholesale & retail | 2026 |
| Information People Limited | Information & communication | 2018 |
| Infraroad Group Ltd | Construction | 2018 |
| Ingel Technologies Limited | Manufacturing | 2000 |
| Ingeniai Ltd | Information & communication | 2025 |
| Ingenics Limited | Extraterritorial | 1978 |
| Ingenio ET Arti Limited | Administrative & support | 2013 |
| Ingenio Group Limited | Extraterritorial | 2021 |
| Ingenio IT Limited | Information & communication | 2018 |
| Inglam Ltd | Wholesale & retail | 2025 |
| Inigo Scout Limited | Wholesale & retail | 2015 |
| Inis Technologies Ltd | Information & communication | 2011 |
| Initia Novi Limited | Financial services | 2014 |
| Initiative Ventures Ltd | Wholesale & retail | 2019 |
| INK Boutique Ltd | Professional & scientific | 2025 |
| Inkerman Developments Ltd | Households | 2015 |
| Inkigai Ltd | Manufacturing | 2024 |
| Inkpen Plastering Services Limited | Construction | 2015 |
| Inkwell Print & Mail C.I.C. | Manufacturing | 2024 |
| Inkwood Ltd | Construction | 2025 |
| Inlandhub Ltd | Wholesale & retail | 2020 |
| Inmar Automation Limited | Manufacturing | 1976 |
| INN1051 Ltd | Transport & logistics | 2023 |
| Inna Cooke Limited | Hospitality | 2022 |
| Inner City Boxing | Arts & recreation | 2011 |
| Inner Heat Ltd | Construction | 2022 |
| Innercare Services (UK) Limited | Health & social care | 2012 |
| Innex Technologies Limited | Information & communication | 2017 |
| Inno-Go Ltd | Wholesale & retail | 2025 |
| Innosaint Ltd | Other services | 2010 |
| Innova Technical Sales Ltd | Professional & scientific | 2014 |
| Innovate Consulting Solutions Ltd | Administrative & support | 2020 |
| Innovate Creative Ltd | Information & communication | 2013 |
| Innovate CX Ltd | Professional & scientific | 2023 |
| Innovate Professional Solutions Limited | Administrative & support | 2020 |
| Innovate Solutions Limited | Administrative & support | 2010 |
| Innovation Aquatics Ltd | Agriculture & fishing | 2015 |
| Innovation Bathrooms Ltd | Wholesale & retail | 2016 |
| Innovation Carpentry & Design Limited | Extraterritorial | 2010 |
| Innovative Connections Limited | Transport & logistics | 2024 |
| Innovative Consultancy UK Limited | Administrative & support | 2004 |
| Innovative Digital Security Solutions (Idss) Ltd | Information & communication | 2025 |
| Innovative Retail Development Limited | Real estate | 2016 |
| Innovence Ltd | Professional & scientific | 2023 |
| Innovise Software Limited | Extraterritorial | 2022 |
| Innovus Engineering Ltd | Professional & scientific | 2018 |
| Innua Europe Ltd | Wholesale & retail | 2012 |
| Inoco Limited | Information & communication | 2025 |
| Inovira Ltd | Other services | 2024 |
| Inovtech Solutions Ltd | Wholesale & retail | 2020 |
| Inprint (Litho) Limited | Manufacturing | 2009 |
| Input Bathrooms Limited | Construction | 2019 |
| Inquisitive Instruments Limited | Professional & scientific | 1997 |
| Inracs (UK) Ltd | Administrative & support | 2025 |
| Ins-U-Loft (Southern) Limited | Construction | 2003 |
| Insi Limited | Wholesale & retail | 2019 |
| Inside OUT Conservatories Limited | Construction | 2003 |
| Inside OUT Consultancy Services Limited | Professional & scientific | 2003 |
| Inside Technology Ltd | Information & communication | 2016 |
| Inside the Box Marketer Ltd | Professional & scientific | 2024 |
| Inside Time Limited | Information & communication | 2003 |
| Insight Travel Retail Consultants Limited | Professional & scientific | 2013 |
| Insignis Consulting Engineers Ltd | Professional & scientific | 2016 |
| Insite (Fixings) Limited | Construction | 1984 |
| Insite (Southern) Limited | Wholesale & retail | 1983 |
| Insite Collection Ltd | Information & communication | 2013 |
| Inso Global Ltd | Wholesale & retail | 2026 |
| Insole Freight Limited | Construction | 2022 |
| Insource Medicare Limited | Health & social care | 2018 |
| Insource Recruitment Limited | Administrative & support | 2024 |
| Inspiration Marine Group Limited | Wholesale & retail | 2006 |
| Inspiration Marine Holdings Limited | Wholesale & retail | 2017 |
| Inspiration Marine Limited | Extraterritorial | 2011 |
| Inspiration Motor Yachts Limited | Wholesale & retail | 2016 |
| Inspiration Multihulls Limited | Wholesale & retail | 2020 |
| Inspire Home Design Ltd | Professional & scientific | 2024 |
| Inspire Landscapes Limited | Administrative & support | 2014 |
| Inspire Learning Partnership | Education | 2014 |
| Inspire Money Ltd | Professional & scientific | 2017 |
| Inspire My Play Ltd | Wholesale & retail | 2020 |
| Inspire Personal Training Ltd | Arts & recreation | 2025 |
| Inspire Property Lettings Ltd | Real estate | 2024 |
| Inspire Stores Ltd | Wholesale & retail | 2024 |
| Inspire Therapy and Pilates Ltd | Other services | 2016 |
| INSPIRE2LIVING Limited | Wholesale & retail | 2021 |
| Inspired Bars & Pubs Biggleswade Ltd | Hospitality | 2019 |
| Inspired Projects (Southern) Ltd | Administrative & support | 2022 |
| Inspirenet Solutions 360 Limited | Wholesale & retail | 2025 |