| Horton Priory Management Limited | Real estate | 2014 |
| Hotspur Holdings Ltd | Real estate | 2023 |
| Hound HUT Dog Grooming Ltd | Other services | 2021 |
| House to Home by Design Ltd | Wholesale & retail | 2025 |
| Housemafia Limited | Hospitality | 2025 |
| Housemartin Limited | Health & social care | 2007 |
| Howard Anthony Property Management Ltd | Real estate | 2026 |
| Howe Property Solutions Limited | Construction | 2018 |
| Hoxbury Ltd | Administrative & support | 2025 |
| Hoxton Music Limited | Wholesale & retail | 2008 |
| HRD Properties Ltd | Real estate | 2017 |
| Humphries & Parks Limited | Wholesale & retail | 1964 |
| Hungate Holdings Ltd | Real estate | 2017 |
| Hutton Poplars Management (NO.2) Limited | Households | 1989 |
| Hutton Poplars Management Limited | Professional & scientific | 1989 |
| Hwrm Ltd | Information & communication | 2024 |
| I & J Kench Management Services Ltd | Professional & scientific | 2021 |
| I AM Digital James Ltd | Professional & scientific | 2024 |
| I-Mist Ltd | Public administration | 2015 |
| I-Volution Platforms Limited | Professional & scientific | 2024 |
| I.B. Transport Service Ltd | Transport & logistics | 2021 |
| IAN Chaplin Consulting Limited | Professional & scientific | 2018 |
| Iato International Ltd | Wholesale & retail | 2015 |
| Ical Produce Ltd | Wholesale & retail | 2024 |
| Icarus Solar Ltd | Energy | 2022 |
| Ice Cleaning Co. Ltd | Administrative & support | 2019 |
| Icon Property Development Ltd | Construction | 2025 |
| Ideal Consultancy (UK) Ltd | Health & social care | 2004 |
| Ideal Scaffolding Limited | Construction | 2000 |
| IDT93 Ltd | Information & communication | 2024 |
| Ignition Motor Club Ltd | Transport & logistics | 2024 |
| Iles Construction Limited | Construction | 2017 |
| Imad Photography Ltd | Professional & scientific | 2016 |
| Imaging-Resource Limited | Health & social care | 2012 |
| Imagino Ltd | Information & communication | 2023 |
| Immaculate Touch Limited | Other services | 2026 |
| Impact Energy People Partners Limited | Administrative & support | 2024 |
| Impact I.M. Limited | Professional & scientific | 1988 |
| Impulse Cleaning Ltd | Administrative & support | 2022 |
| IN Motion Training Ltd | Education | 2022 |
| IN the Room Wine Limited | Wholesale & retail | 2022 |
| Inclusion Sports Ltd | Education | 2024 |
| Incommsec Ltd | Professional & scientific | 2010 |
| Indie PUB Group Ltd | Hospitality | 2018 |
| Individual Developments Limited | Construction | 2006 |
| Indocco Limited | Real estate | 2018 |
| Inevexco Ltd | Financial services | 2011 |
| Infinity Coffee House Ltd | Hospitality | 2017 |
| Infinity Commercial Property Limited | Real estate | 2018 |
| Infinity Fitness-Uk Ltd | Arts & recreation | 2012 |
| Infinity Fitness-Uk Sittingbourne Ltd | Arts & recreation | 2023 |
| Infinity Properties Ltd | Real estate | 2018 |
| Infinity Rooms to Rent Ltd | Real estate | 2018 |
| Ingen Distribution UK Limited | Wholesale & retail | 2014 |
| Ingenious Exec Limited | Professional & scientific | 2018 |
| Ingenious Property Services Limited | Real estate | 2015 |
| Initar Ltd | Information & communication | 2020 |
| INK Homes Limited | Construction | 2018 |
| Inn Bricks and Mortar Limited | Real estate | 2023 |
| Innhome Facilities Services Limited | Administrative & support | 2018 |
| Innovation & Incentives Limited | Professional & scientific | 2023 |
| Insulean Ltd | Health & social care | 2019 |
| INT Section Ltd | Administrative & support | 2018 |
| Intangles LAB UK Private Limited | Manufacturing | 2024 |
| Intelligent Fruit Ltd | Agriculture & fishing | 2012 |
| International Display Fixtures Limited | Wholesale & retail | 2010 |
| Investo Capital Ltd | Other services | 2023 |
| Invicta Law Limited | Professional & scientific | 2016 |
| Iplace Limited | Construction | 2008 |
| IQ3 Ltd | Construction | 2023 |
| Iron Mill Property Ltd | Real estate | 2020 |
| Isand (Domiciliary Care) Limited | Health & social care | 2011 |
| Isand Limited | Health & social care | 2004 |
| Iska Recovery Ltd | Arts & recreation | 2024 |
| Isla Law Limited | Professional & scientific | 2017 |
| Island ROW LLP | | 2006 |
| It's Travel Unlimited Ltd | Administrative & support | 2023 |
| Itak (Cartington) Limited | Extraterritorial | 2016 |
| ITB (West Malling) Limited | Real estate | 2023 |
| J & P Moore Limited | Construction | 2013 |
| J & S Electrical (Kent) Limited | Construction | 2008 |
| J H G Services Limited | Professional & scientific | 2022 |
| J Hampson Ltd | Construction | 2023 |
| J J Leadenhall Limited | Professional & scientific | 2013 |
| J Jerwood Ltd | Administrative & support | 2015 |
| J N L Carpentry Limited | Construction | 2007 |
| J P B Creatives Limited | Wholesale & retail | 2024 |
| J&L Property Capital Ltd | Real estate | 2024 |
| J.Burr & Co Ltd. | Construction | 2016 |
| Jabu Services Ltd | Administrative & support | 2025 |
| Jack Wilkes Services Limited | Construction | 2018 |
| Jacksonandcophotography Ltd | Professional & scientific | 2012 |
| JAG Data Science Limited | Information & communication | 2016 |
| Jaklyn Limited | Health & social care | 2025 |
| James & OLA Dance Academy Limited | Professional & scientific | 2008 |
| James Muir Limited | Real estate | 2005 |
| James Property & Construction Consultancy Limited | Professional & scientific | 2016 |
| Jandp Healthcare Services Ltd | Health & social care | 2022 |
| Janined HR Consulting Services Ltd | Administrative & support | 2021 |
| Janus Homecare Systems Limited | Construction | 2014 |