| Imariplan Limited | Wholesale & retail | 1992 |
| Imaroush Ltd | Hospitality | 2025 |
| Imasro Limited | Extraterritorial | 2009 |
| Imation Marketing Ltd | Professional & scientific | 2019 |
| Imax Property & Room Lets Ltd | Households | 2021 |
| Imayla C.I.C. | Health & social care | 2001 |
| IMB Groundworks Ltd | Construction | 2025 |
| Imber Drinks Ltd | Manufacturing | 2025 |
| Imbr Limited | Transport & logistics | 2024 |
| IMC Ceramicoat Limited | Professional & scientific | 2017 |
| IMC St.David's Ltd | Health & social care | 2000 |
| IMC Toys (UK) Limited | Wholesale & retail | 2004 |
| Imec Cambridge UK Limited | Professional & scientific | 2024 |
| Imeg Solution Limited | Manufacturing | 2012 |
| Imetrum Limited | Manufacturing | 2003 |
| IMH (Bristol) Ltd | Hospitality | 2025 |
| Imitec Limited | Professional & scientific | 2014 |
| IMM Asset Management Limited | Real estate | 2024 |
| Immacuwall Ltd | Construction | 2018 |
| Immanuel Christian School Limited | Education | 2011 |
| Immcont LP | | 2012 |
| Immersed in Nature Limited | Arts & recreation | 2017 |
| Immersive Ideas Ltd | Arts & recreation | 2024 |
| Immersive Labs Holdings Limited | Information & communication | 2018 |
| Immersive Labs Ltd | Information & communication | 2017 |
| Immersive Labs Nominee Limited | Administrative & support | 2021 |
| Immi Global Limited | Information & communication | 2025 |
| Immingham Power Limited | Energy | 2017 |
| Immunehealth Ltd | Wholesale & retail | 2020 |
| Immunity Financial Solutions Limited | Financial services | 2012 |
| Immunohaematology Insights Ltd | Professional & scientific | 2025 |
| Immy Ndagire Ltd | Health & social care | 2015 |
| Imob Care Ltd | Health & social care | 2018 |
| Imp@Ss Ltd | Information & communication | 2014 |
| Impact Accelerator Ltd | Professional & scientific | 2020 |
| Impact Asset Holdings Limited | Professional & scientific | 2021 |
| Impact Bars Ltd | Hospitality | 2019 |
| Impact Consultancy SW Ltd | Administrative & support | 2026 |
| Impact Elite Ltd | Administrative & support | 2024 |
| Impact Generators Limited | Professional & scientific | 2016 |
| Impact Gym Wickwar Ltd | Arts & recreation | 2021 |
| Impact IT Solutions (UK) Limited | Information & communication | 2004 |
| Impact IT Solutions Limited | Extraterritorial | 2022 |
| Impact Mentoring Holdings Ltd | Real estate | 2026 |
| Impact Mentoring Ltd | Education | 2017 |
| Impact Metrology Systems Ltd | Construction | 2015 |
| Impact Properties UK Limited | Construction | 2009 |
| Impact Solution Consulting Limited | Information & communication | 2015 |
| Impact Stock Holding Limited | Wholesale & retail | 2021 |
| Impact Streetworks Solutions Ltd | Professional & scientific | 2026 |
| Impact Technology Services Limited | Information & communication | 2008 |
| Impact Training & Consultation Ltd | Education | 2002 |
| Impactin Education Ltd | Education | 2026 |
| Impactwild CIC | Information & communication | 2025 |
| Impala Pictures Limited | Information & communication | 2017 |
| Impala Terminals Infrastructure UK Ltd. | Wholesale & retail | 2014 |
| Impax Consulting Limited | Professional & scientific | 2018 |
| Impeccable Finishes Ltd | Construction | 2016 |
| Impeccable Highlights Ltd | Administrative & support | 2025 |
| Impeccable Roofing Ltd | Other services | 2018 |
| Impera Logistics Ltd | Transport & logistics | 2019 |
| Imperial Aivol Consultancy Ltd | Administrative & support | 2026 |
| Imperial Bodyworks Ltd | Wholesale & retail | 2026 |
| Imperial Brands Enterprise Finance Limited | Financial services | 2003 |
| Imperial Brands Finance PLC | Professional & scientific | 1996 |
| Imperial Brands PLC | Professional & scientific | 1996 |
| Imperial Brands Ventures Finance Limited | Financial services | 2021 |
| Imperial Brands Ventures Holdings (1) Limited | Financial services | 2021 |
| Imperial Brands Ventures Holdings (2) Limited | Financial services | 2021 |
| Imperial Brands Ventures Holdings Limited | Financial services | 2019 |
| Imperial Brands Ventures Limited | Administrative & support | 2018 |
| Imperial Developments (Bristol) Limited | Construction | 2015 |
| Imperial Distributors Ltd | Wholesale & retail | 2025 |
| Imperial Fire & Security Limited | Construction | 2002 |
| Imperial Fleet Limited | Administrative & support | 2022 |
| Imperial Fresh Limited | Wholesale & retail | 2025 |
| Imperial Holdings (Bristol) Limited | Financial services | 2018 |
| Imperial Hotel Limited | Hospitality | 2023 |
| Imperial Investments Limited | Financial services | 1986 |
| Imperial Jade KOI Limited | Wholesale & retail | 2018 |
| Imperial Scaffolding and Rigging Limited | Construction | 2019 |
| Imperial Technical Services Limited | Professional & scientific | 2007 |
| Imperial Tobacco Altadis Limited | Professional & scientific | 2008 |
| Imperial Tobacco Capital Assets (1) | Professional & scientific | 2005 |
| Imperial Tobacco Capital Assets (2) | Professional & scientific | 2005 |
| Imperial Tobacco Capital Assets (3) | Professional & scientific | 2005 |
| Imperial Tobacco Capital Assets (4) | Professional & scientific | 2007 |
| Imperial Tobacco Group Limited | Professional & scientific | 1902 |
| Imperial Tobacco Holdings (1) Limited | Financial services | 1989 |
| Imperial Tobacco Holdings (2007) Limited | Financial services | 2006 |
| Imperial Tobacco Holdings Limited | Financial services | 1995 |
| Imperial Tobacco Initiatives | Professional & scientific | 2004 |
| Imperial Tobacco Lacroix Limited | Professional & scientific | 2008 |
| Imperial Tobacco Limited | Wholesale & retail | 1984 |
| Imperial Tobacco Overseas (Polska) Limited | Financial services | 2003 |
| Imperial Tobacco Overseas Holdings (1) Limited | Financial services | 2002 |
| Imperial Tobacco Overseas Holdings (2) Limited | Financial services | 2002 |
| Imperial Tobacco Overseas Holdings (3) Limited | Professional & scientific | 2007 |
| Imperial Tobacco Overseas Holdings (4) Limited | Financial services | 2019 |
| Imperial Tobacco Overseas Holdings Ltd | Financial services | 1998 |