| Illyrian Properties Ltd. | Construction | 2021 |
| Ilratcal Ltd | Transport & logistics | 2021 |
| IM Engineering Consultants Ltd | Construction | 2022 |
| Image HUT Limited | Other services | 2019 |
| Imagecare Technical Services Limited | Information & communication | 1998 |
| Images Direct Limited | Information & communication | 1997 |
| Imaginations Run Wild Limited | Education | 2023 |
| Imaginative Minds Limited | Information & communication | 1989 |
| IMAGINED-4-YOU Limited | Wholesale & retail | 2021 |
| IMD Electric Ltd | Professional & scientific | 2026 |
| IMDAD1 Ltd | Transport & logistics | 2023 |
| Imfiyazioux Ltd | Transport & logistics | 2023 |
| IMH Associates Limited | Professional & scientific | 1995 |
| Imolis Limited | Professional & scientific | 2026 |
| Impactability Limited | Education | 2002 |
| Imperial Assets 77 Ltd | Real estate | 2025 |
| Imperial Garments Ltd | Manufacturing | 2013 |
| Imperium Holdings Ltd | Financial services | 2019 |
| IN Front Digital Limited | Information & communication | 2013 |
| IN the Community Limited | Education | 2009 |
| In-Form Solutions Ltd | Professional & scientific | 2000 |
| In-House Parallel Ltd | Administrative & support | 2025 |
| Inclusive Careers Ltd | Administrative & support | 2012 |
| Incorporated Sutton Coldfield Golf Club(The) | Arts & recreation | 1893 |
| Indalo Property Limited | Real estate | 2018 |
| Indee Consultancy Limited | Health & social care | 2013 |
| Independent HR Investigations Ltd | Professional & scientific | 2020 |
| Indian Furniture Direct Limited | Administrative & support | 2002 |
| Indian Nights (Sutton) Ltd | Hospitality | 2026 |
| Industrial & Logistics Property Partners LLP | | 2022 |
| Industrial Manufacturing Solutions Ltd | Wholesale & retail | 2023 |
| Industrial Penstocks and Valves Limited | Manufacturing | 2022 |
| Industrial Webs Limited | Information & communication | 1998 |
| Infinity Couture Ltd | Wholesale & retail | 2023 |
| Infinity Debt Recovery Limited | Financial services | 2010 |
| Infinity Security Ltd | Administrative & support | 2011 |
| Infinity SQD Limited | Professional & scientific | 2020 |
| Influential Digital Services Limited | Professional & scientific | 2019 |
| Info Studio Limited | Professional & scientific | 2016 |
| Infolegal Limited | Professional & scientific | 2011 |
| Inform Accounting Limited | Professional & scientific | 2009 |
| Infoswift Solutions Limited | Information & communication | 2007 |
| Infraspatial Design UK Ltd | Professional & scientific | 2026 |
| Infusedance Ltd | Arts & recreation | 2015 |
| Ingall Services Limited | Extraterritorial | 1947 |
| Ingenious Property Solutions Ltd | Real estate | 2019 |
| Inglewood Property Limited | Real estate | 2021 |
| Ingram Advisory Limited | Administrative & support | 2025 |
| INICIO-3 Limited | Professional & scientific | 2023 |
| Initia 360 Ltd | Wholesale & retail | 2018 |
| Injiuk Ltd | Hospitality | 2025 |
| INK Rofain International Limited | Construction | 2021 |
| Inkygoodness Ltd | Professional & scientific | 2019 |
| Innovate Electrical Services Limited | Construction | 2018 |
| Innovate Pro Consulting Ltd | Information & communication | 2025 |
| Innovate Repeat Ltd | Construction | 2017 |
| Innovating Minds CIC | Other services | 2016 |
| Innovating Minds Digital Limited | Education | 2019 |
| Innovating Minds Group Limited | Financial services | 2019 |
| Innovative Design and Build Ltd | Real estate | 2019 |
| Innovative Property and Lettings Ltd | Real estate | 2021 |
| INOV8UK Limited | Real estate | 2023 |
| Inowno F&B Limited | Information & communication | 2013 |
| Inpharm Solutions Ltd | Wholesale & retail | 2021 |
| Inquisitive Minds Matter Ltd | Education | 2019 |
| Insight Care Group Ltd | Health & social care | 2020 |
| Insignia Crisis and Reputation Management EOT Limited | Professional & scientific | 2025 |
| Insignia Crisis and Reputation Management Limited | Professional & scientific | 2008 |
| Insignia Registrations Limited | Wholesale & retail | 2004 |
| Insinc Properties Limited | Real estate | 2025 |
| Inspire IOT Ltd | Administrative & support | 2024 |
| Inspired Business Vision Limited | Professional & scientific | 2011 |
| Inspired Progression Limited | Education | 2019 |
| Install Mechanical Services Ltd | Administrative & support | 2011 |
| Instay.Ai Ltd | Information & communication | 2025 |
| Instep Technologies Limited | Information & communication | 2014 |
| Instinctive Property Management Limited | Households | 2024 |
| Insurepod (London) Limited | Administrative & support | 2024 |
| Integral Communications Property Investments Limited | Real estate | 2025 |
| Integrity Energy Limited | Administrative & support | 2003 |
| Intelligent Property Consultants Ltd. | Real estate | 2021 |
| Intelligent Shading Limited | Wholesale & retail | 2018 |
| Intelligent World Limited | Manufacturing | 2018 |
| Intellisphere Limited | Wholesale & retail | 2010 |
| Intellix Web Specops Ltd | Information & communication | 2012 |
| Intelxlent Ltd | Professional & scientific | 2026 |
| Inter City Building Limited | Real estate | 2007 |
| Interface Solihull Management Limited | Real estate | 2002 |
| Interior Allure Ltd | Professional & scientific | 2024 |
| Interior Joinery Contracts Ltd | Construction | 2012 |
| Interlink Electrical Holdings Limited | Financial services | 2018 |
| Interlink Group Limited | Financial services | 2020 |
| Intermar Steel Limited | Wholesale & retail | 2013 |
| International College of Aesthetic Medicine (Icam) Ltd | Education | 2018 |
| International Credit Score Ltd | Financial services | 2025 |
| International Estate Solutions Limited | Information & communication | 2023 |
| International Recruitment Limited | Education | 2023 |
| International Recycling Services Limited | Water & waste | 2010 |
| International Taekwondo Council Ltd | Arts & recreation | 2018 |
| International Trade Management Limited | Wholesale & retail | 1992 |