| IMA Civil & Building Engineering Ltd | Construction | 2021 |
| Imaan Tech Ltd | Information & communication | 2019 |
| Image HQ Global Ltd | Information & communication | 2022 |
| Image Media Limited | Professional & scientific | 2011 |
| Image Tours & Travels (UK) Ltd | Administrative & support | 2025 |
| Images by Judith Ltd | Wholesale & retail | 2025 |
| Images Hairdressing and Hair Extensions Centre Ltd | Other services | 2020 |
| Imaginatal 3 Ltd | Health & social care | 2022 |
| Imagination Growth Marketing Limited | Professional & scientific | 2018 |
| Imagination Photos Limited | Professional & scientific | 2026 |
| Imagination Travels Ltd | Wholesale & retail | 2016 |
| Imagine Homes and Properties Limited | Real estate | 2016 |
| Imani Properties (Stratford) Ltd | Real estate | 2016 |
| Imap Building & Maintenance UK Ltd | Construction | 2013 |
| Imaraa Co Ltd | Wholesale & retail | 2026 |
| Imax Pro Cctv & Security Alarms Ltd | Wholesale & retail | 2022 |
| IMG Building Ltd | Construction | 2014 |
| Imgn Interiors Limited | Construction | 2022 |
| IMI Tech Support Ltd | Information & communication | 2012 |
| Imimpact Limited | Professional & scientific | 2023 |
| Immaculate Aesthetic London Ltd | Health & social care | 2024 |
| Immediate Fire Protection Limited | Public administration | 2024 |
| Immediate Property Solutions Ltd | Real estate | 2014 |
| Immo Estate Ltd | Real estate | 2023 |
| Immo Properties Ltd | Real estate | 2024 |
| Immy Executive Ltd | Transport & logistics | 2016 |
| IMO State Union UK Limited | Other services | 2019 |
| Imoscan Ltd | Information & communication | 2026 |
| Imot Ltd | Wholesale & retail | 2010 |
| Impact Generation Initiatives | Information & communication | 2021 |
| Impact Multi Consortium Limited | Construction | 2005 |
| Impact Roofing & Guttering Ltd | Construction | 2022 |
| Impact Sport and Fitness Limited | Health & social care | 2017 |
| Impact Walls & Ceilings Ltd | Construction | 2020 |
| Impakt X Ltd | Education | 2019 |
| Imperia Estates Ltd | Real estate | 2025 |
| Imperial Array Ltd | Hospitality | 2024 |
| Imperial Chef London Limited | Hospitality | 2025 |
| Imperial Education Group Ltd | Other services | 2021 |
| Imperial Glass Ltd | Wholesale & retail | 2014 |
| Imperial Recruit Group Limited | Administrative & support | 2023 |
| Impram Construction & Building Services Ltd | Construction | 2023 |
| Impress Solutions (I) Limited | Information & communication | 2024 |
| Impress Solutions (II) Limited | Information & communication | 2024 |
| Impress Solutions (III) Limited | Information & communication | 2024 |
| Impress Solutions Limited | Information & communication | 1997 |
| Impress the Examiner Ltd | Information & communication | 2018 |
| Impress Worldwide Ltd | Wholesale & retail | 2023 |
| Impulse Physiotherapy Limited | Health & social care | 2015 |
| Imrc Ltd | Construction | 2014 |
| Imre Properties Limited | Real estate | 2024 |
| Imss Limited | Education | 2023 |
| Imtek Limited | Professional & scientific | 2017 |
| Imtishak Investments Limited | Real estate | 2019 |
| Imuv Ltd | Wholesale & retail | 2013 |
| IMV Contractors Ltd | Construction | 2014 |
| IMV London Ltd | Education | 2020 |
| IN Front Autos Limited | Wholesale & retail | 2011 |
| IN House Decorator Ltd | Construction | 2015 |
| IN Motion CGI Ltd | Professional & scientific | 2025 |
| IN My Father's House Limited | Other services | 2022 |
| IN Real Holding Ltd | Financial services | 2024 |
| IN Real Properties Ltd | Real estate | 2024 |
| IN the Yard Limited | Wholesale & retail | 2016 |
| In-World Education Limited | Education | 2025 |
| Inaadeen Ltd | Wholesale & retail | 2024 |
| Inaayah Limited | Wholesale & retail | 2019 |
| Inarah Labs Ltd | Information & communication | 2026 |
| Inayah Property Holdings Ltd | Real estate | 2020 |
| Incat Limited | Professional & scientific | 2019 |
| Incendium Home Solutions Limited | Construction | 2016 |
| Inceptions Sales Solutions Ltd | Professional & scientific | 2025 |
| Incipit Properties Limited | Real estate | 2017 |
| Incisive Consultancy Limited | Professional & scientific | 2025 |
| Incite Gravity Ltd | Information & communication | 2023 |
| Inclusion Matters Consultancy Ltd | Education | 2026 |
| Inclusion Teacher Ltd | Education | 2024 |
| Inclusive Stays Ltd | Hospitality | 2025 |
| Inclusiveconnect CIC | Education | 2025 |
| Inco Fast Limited | Hospitality | 2018 |
| Income MAX Community Interest Company | Health & social care | 2009 |
| Independant Community Support Limited | Health & social care | 2014 |
| Independent Home Care and Support Services Ltd | Administrative & support | 2015 |
| Independent Horizons Limited | Health & social care | 2024 |
| Inder Paul's World Ltd | Wholesale & retail | 2022 |
| Inder Properties Limited | Real estate | 2025 |
| Index Learning Ltd | Education | 2019 |
| Index Waste Management Ltd | Water & waste | 2026 |
| Indeza Sourcing Ltd | Wholesale & retail | 2025 |
| Indian Expats Ltd | Information & communication | 2015 |
| Indian Oasis ( UK ) Ltd | Administrative & support | 2017 |
| Indian Ocean Essex Ltd | Hospitality | 2019 |
| Indian Ocean Events Ltd | Hospitality | 2015 |
| Indian Ocean Romford Ltd | Hospitality | 2025 |
| Indicate FM Limited | Administrative & support | 2025 |
| Indigo & Isle UK Ltd | Professional & scientific | 2026 |
| Indigo Placements Ltd | Professional & scientific | 2023 |
| Indigo Solutions Group Limited | Administrative & support | 2025 |
| Industrial Lift Services Limited | Extraterritorial | 1968 |
| Industrie Futura Limited | Other services | 2017 |