| Interconnect Network Systems Limited | Information & communication | 1998 |
| Interface Condition Monitoring Limited | Professional & scientific | 1999 |
| Intergrale Limited | Professional & scientific | 2019 |
| Interior Envy Ltd | Wholesale & retail | 2025 |
| Interior Management Systems Ltd | Construction | 2018 |
| Interior Surfaces Specialists Limited | Construction | 2013 |
| Interiors M&K Ltd | Construction | 2024 |
| Intermedi Group Limited | Health & social care | 2017 |
| International Alliance of Professional Business Elites (Iapbe) Ltd | Professional & scientific | 2018 |
| International Academy of Ruqyah Ltd | Health & social care | 2025 |
| International Additive Manufacturing Ltd | Manufacturing | 2024 |
| International Aerospace and Defence Alloys Limited | Wholesale & retail | 2025 |
| International Business Register Limited | Administrative & support | 2026 |
| International Centre for Applied Ethics and Public Affairs CIC | Information & communication | 2023 |
| International Centre for Industrial Transformation (UK) Ltd | Professional & scientific | 2025 |
| International Certification Agency Limited | Administrative & support | 2010 |
| International College for SEX and Relationship Therapy Ltd | Information & communication | 2026 |
| International Compliance Agency Limited | Administrative & support | 2025 |
| International Energy Products Limited | Wholesale & retail | 2017 |
| International Energy Products Middle East Limited | Manufacturing | 2022 |
| International Forest Products (UK) Ltd | Professional & scientific | 2005 |
| International Forging & Heat Treatment Limited | Professional & scientific | 2024 |
| International Freight Solutions Ltd. | Transport & logistics | 2016 |
| International Graduate Insight Group Ltd | Professional & scientific | 2005 |
| International Investment Consultancy Ltd | Construction | 2015 |
| International Management Holdings Limited | Financial services | 2022 |
| International Mining & Marine Ltd | Professional & scientific | 2011 |
| International Organisation Development Ltd. | Professional & scientific | 1998 |
| International Play Space Limited | Professional & scientific | 2017 |
| International Products Ltd | Wholesale & retail | 2018 |
| International Project and Property Management Ltd | Construction | 2020 |
| International Revival Meeting | Other services | 2019 |
| International Transport Solutions Limited | Transport & logistics | 2026 |
| Intero Trade Ltd. | Wholesale & retail | 2015 |
| Interparts Automotive Limited | Wholesale & retail | 2018 |
| Interra Smart Building Solutions Limited | Information & communication | 2020 |
| Intersect Design and Consulting Ltd | Information & communication | 2022 |
| Interspan Aquila Ltd | Administrative & support | 2025 |
| Interspan Europe Limited | Administrative & support | 2010 |
| Interspan Repair and Strengthening Ltd | Administrative & support | 2021 |
| Intex Signs & Graphics Limited | Professional & scientific | 2018 |
| Intimate Secrets Lingerie Limited | Wholesale & retail | 2024 |
| Into Professional Ltd | Professional & scientific | 2010 |
| Intone Communications Limited | Administrative & support | 2003 |
| Intracave Limited | Hospitality | 1984 |
| Intraplex Ltd | Administrative & support | 2017 |
| Intrapology Ltd | Information & communication | 2024 |
| Intreco Limited | Professional & scientific | 2004 |
| Intrepid Minds Ltd | Professional & scientific | 2010 |
| Intrepidinktattoostudio Limited | Other services | 2023 |
| Introspective Training & Consultancy Ltd | Information & communication | 2003 |
| Inventive Products Ltd | Manufacturing | 2015 |
| Inventorypro Ltd | Real estate | 2023 |
| Inverteck Limited | Construction | 2009 |
| Invest Germany UK Ltd | Financial services | 2025 |
| Invest Oasis Ltd | Real estate | 2023 |
| Investates Developments Limited | Construction | 1989 |
| Investing One Limited | Professional & scientific | 2022 |
| INVESTING4NOOBS Limited | Administrative & support | 2017 |
| Investments (North West) Limited | Real estate | 2009 |
| Investo Team Ltd | Real estate | 2024 |
| Invica Energy Limited | Financial services | 2022 |
| Invica Industries Group Limited | Professional & scientific | 2011 |
| Invica Industries Holdings Limited | Professional & scientific | 2006 |
| Invica Industries Limited | Professional & scientific | 1994 |
| Invica Limited | Administrative & support | 2021 |
| Invictus Aurum Ltd | Real estate | 2026 |
| Invictus Business Advisory Limited | Professional & scientific | 2014 |
| Invitewith Ltd | Information & communication | 2025 |
| Invoaura Ltd. | Transport & logistics | 2025 |
| INX Limited | Information & communication | 2008 |
| Inxy Prints Ltd | Manufacturing | 2025 |
| Inzamaq Limited | Wholesale & retail | 2025 |
| IOD Parc EOT Ltd | Financial services | 2021 |
| Ionic Catering Limited | Wholesale & retail | 2015 |
| Ionut & Mada Limited | Transport & logistics | 2023 |
| Iora Codnor 2012 Limited | Health & social care | 2010 |
| Iora Properties Limited | Real estate | 2011 |
| Iotisan Ltd | Information & communication | 2023 |
| IP Recycling Limited | Water & waste | 2021 |
| IPD Contractors Ltd | Construction | 2022 |
| IPE Developments Ltd | Manufacturing | 2011 |
| IPE Fabrications Limited | Manufacturing | 2020 |
| IPE Holdings Limited | Professional & scientific | 2025 |
| IPH Holdings Ltd | Professional & scientific | 2025 |
| IPM Holdings Group Limited | Administrative & support | 2024 |
| IPM Leisure Ltd | Administrative & support | 2023 |
| IPM Payroll Ltd | Administrative & support | 2024 |
| IPM Security & FM Ltd | Administrative & support | 2023 |
| IPM Stadia & Events Ltd | Administrative & support | 2023 |
| IPM Training Group Ltd | Health & social care | 2023 |
| Ipoa Limited | Professional & scientific | 2020 |
| IPRINT365 Ltd | Manufacturing | 2023 |
| Ipro Electrical Services Limited | Construction | 2022 |
| Ipsumweb Ltd | Information & communication | 2025 |
| IQ Accounts Ltd | Professional & scientific | 2019 |
| IQ Cardiac Ltd | Real estate | 2019 |
| IQ Removals Ltd | Transport & logistics | 2020 |
| Iqbal & Co S35 Ltd | Hospitality | 2026 |
| Iqra 7 Flavours Ltd | Hospitality | 2026 |