| Hump IT & Dump IT (SW) Limited | Water & waste | 2012 |
| Humphries & Co Accountants Ltd | Professional & scientific | 2015 |
| Humphries Technology Limited | Information & communication | 2016 |
| Hungate Cottages Limited | Hospitality | 1980 |
| Hungate House Cottages Limited | Hospitality | 1980 |
| Hunt (Global) Ltd | Manufacturing | 2014 |
| Hunt Hanson Ltd | Professional & scientific | 2011 |
| Hunters Accountants Limited | Professional & scientific | 2011 |
| Hunts Pallets Limited | Wholesale & retail | 2002 |
| Huxley Digital Limited | Information & communication | 2015 |
| HW Financial Solutions Ltd | Financial services | 2021 |
| Hweolwyrtha Limited | Hospitality | 2023 |
| Hyde Lane Holdings Limited | Mining & quarrying | 2017 |
| I B Scott Associates Limited | Wholesale & retail | 2003 |
| I C Signalling Limited | Administrative & support | 2010 |
| I Compete Events Ltd | Arts & recreation | 2024 |
| I&B Property Limited | Real estate | 2022 |
| I. & J. Bannerman Limited | Administrative & support | 1991 |
| I2 Group Limited | Information & communication | 2025 |
| I2 Limited | Information & communication | 2025 |
| I23 Design Ltd | Professional & scientific | 2017 |
| Iaeste UK Ltd | Administrative & support | 2023 |
| Iain Penney Plant Hire Limited | Construction | 2003 |
| IAN Adams Associates Limited | Information & communication | 2010 |
| IAN Brambley Residential Ltd | Real estate | 2026 |
| IAN Harris Limited | Professional & scientific | 2018 |
| IAN Nurden Limited | Construction | 2000 |
| IAN Potts Services Ltd | Construction | 2025 |
| IC Accounts Solution Ltd | Information & communication | 2018 |
| Ican Production Limited | Hospitality | 2012 |
| Icarus Dental Ltd | Health & social care | 2017 |
| Icjd Ltd | Professional & scientific | 2014 |
| Iclimb Ltd | Information & communication | 2021 |
| Iconic Driveways Ltd | Construction | 2025 |
| Iconsultancy UK Ltd | Information & communication | 2014 |
| IDC Conveyors Limited | Manufacturing | 2001 |
| Idover Garage Ltd | Wholesale & retail | 2025 |
| IEP Ventures Ltd | Manufacturing | 2015 |
| IFA Acquisitions Ltd | Professional & scientific | 2017 |
| IFA Hub Ltd | Information & communication | 2026 |
| IFA Magazine Publications Limited | Information & communication | 2011 |
| Ifin Partnership Limited | Professional & scientific | 2025 |
| Ifixer Ltd | Information & communication | 2015 |
| Ignia Coaching & Training Ltd | Professional & scientific | 2025 |
| IJL Groundworks Ltd | Construction | 2019 |
| IL Mulino Pizza C.I.C. | Hospitality | 2020 |
| Illeso Holdings Ltd | Information & communication | 2025 |
| Illuminate Bristol Limited | Construction | 2025 |
| Im-Hr Ltd | Other services | 2018 |
| Image Business Solutions Limited | Professional & scientific | 2000 |
| Image Centre Limited | Manufacturing | 2016 |
| Image Creative Limited | Extraterritorial | 2016 |
| Imbo Technologies Ltd | Financial services | 2021 |
| Imbrace Ltd | Wholesale & retail | 2021 |
| Immaculatep Care Limited | Health & social care | 2024 |
| Immigrant Opera Ltd | Wholesale & retail | 2025 |
| Impact Body Repairs Limited | Wholesale & retail | 2015 |
| Impelous Ltd | Administrative & support | 2008 |
| Imperial Cleaning Services (South West) Limited | Administrative & support | 2023 |
| IMS Business Information Services Limited | Professional & scientific | 2009 |
| IN Other Words Translation Services Ltd | Professional & scientific | 2007 |
| Independent Financial Services 4 YOU Limited | Financial services | 2010 |
| Independent Numbers Limited | Administrative & support | 2013 |
| Indigo Designs Property Development Limited | Construction | 2021 |
| Industrial Docking Ltd | Manufacturing | 2023 |
| Industrial Plasters Ltd | Wholesale & retail | 2013 |
| Induvia Limited | Agriculture & fishing | 2020 |
| Infbox Ltd | Information & communication | 2016 |
| Infinitus Consilium Limited | Information & communication | 2009 |
| Infinity PD Limited | Wholesale & retail | 2022 |
| Infinity TUR Travel UK Ltd | Administrative & support | 2026 |
| Inflection Point MSP Ltd. | Information & communication | 2010 |
| Infoproj Ltd | Information & communication | 2014 |
| Inla Property Limited | Real estate | 2019 |
| Innovata Limited | Health & social care | 1987 |
| Innovatech Media Ltd | Information & communication | 2009 |
| Innovation Interiors (Wall Cladding and Flooring) Ltd | Construction | 2022 |
| Innovative Imports Europe Ltd | Professional & scientific | 2022 |
| Inovate Health Limited | Manufacturing | 2010 |
| Inscope Limited | Extraterritorial | 2018 |
| Insignia Limited | Wholesale & retail | 1981 |
| Inspirational Consultancy Limited | Real estate | 2015 |
| Inspire Pole Dance & Aerial Arts Studios Ltd | Arts & recreation | 2022 |
| Inspired Technical Leadership Ltd | Real estate | 2021 |
| Instant Services (UK) Limited | Real estate | 1996 |
| Intechnia Limited | Information & communication | 2000 |
| Integrated Fire & Security Services Ltd | Construction | 2026 |
| Integrated Solutions Group Limited | Construction | 2020 |
| Integrity Pensions and Investments Limited | Financial services | 2010 |
| Intellica IT Limited | Information & communication | 2014 |
| Intelligent Infrastructure Group Limited | Information & communication | 2024 |
| Intelliscape Limited | Information & communication | 2025 |
| Inteq Controls Limited | Information & communication | 2020 |
| Inteq Group Limited | Information & communication | 2013 |
| Inteq Integration Limited | Manufacturing | 2001 |
| Inteq Systems Limited | Information & communication | 2004 |
| Interactions Group Ltd | Information & communication | 2025 |
| Intercast Communications Limited | Information & communication | 2013 |
| Intern Europe Limited | Education | 2013 |
| International Film and Video Productions Limited | Professional & scientific | 2019 |