| HMT Care Holdings Limited | Financial services | 2023 |
| HMT Care Limited | Health & social care | 2002 |
| Hockley & Thomas Properties Ltd | Real estate | 2025 |
| Holism Nutrition Ltd | Information & communication | 2018 |
| Home Comfort Heating Limited | Construction | 1993 |
| Home Maid Services Ltd | Administrative & support | 2023 |
| Home Service Complete Care LLP | | 2009 |
| Hope Care Limited | Real estate | 2007 |
| Horse and Farm Limited | Real estate | 2009 |
| Horsebolt Limited | Wholesale & retail | 2007 |
| Horsham Tyres Limited | Water & waste | 2016 |
| Hotdrop Limited | Manufacturing | 2019 |
| House Rail Ltd | Construction | 2022 |
| HSE Training Group Ltd | Education | 2018 |
| HSE Training Ltd | Education | 2006 |
| Hudson Family Properties LLP | | 2019 |
| Huntingdon Precision Engineering Limited | Real estate | 1965 |
| Husk Farms Limited | Agriculture & fishing | 2024 |
| HWG Kent Ltd | Administrative & support | 2012 |
| Hygibond Interiors Limited | Construction | 2023 |
| I J Pask Construction Ltd | Construction | 2023 |
| I Kandy Lawns Ltd | Administrative & support | 2022 |
| ICG Associates Limited | Information & communication | 2010 |
| Icom (UK) Limited | Wholesale & retail | 1979 |
| Iconiq Homes Ltd | Construction | 2017 |
| IDA Real Estate Limited | Financial services | 2022 |
| Ideasie Ltd | Professional & scientific | 2021 |
| Ifauk Ltd | Financial services | 2007 |
| Illustration Agent Limited | Extraterritorial | 2018 |
| Imaginar Limited | Professional & scientific | 2007 |
| Imaginary Friends Games LLP | | 2019 |
| Immersive Studio Limited | Information & communication | 2016 |
| IN a Nother Business Limited | Professional & scientific | 1997 |
| Inala Nature Tours Limited | Administrative & support | 2019 |
| Indus Oral Surgery Limited | Health & social care | 2021 |
| Industrial Electronic Controls Limited | Manufacturing | 2002 |
| Industrial Lubricants (UK) Limited | Wholesale & retail | 1998 |
| Industrial Lubricants Limited | Extraterritorial | 2005 |
| Infinitum Holdings Limited | Financial services | 2018 |
| Ingenso Limited | Manufacturing | 2000 |
| Ingram Plant Limited | Wholesale & retail | 2017 |
| Initial Medic Services Ltd | Administrative & support | 2017 |
| INK Black Sea Ltd | Arts & recreation | 2022 |
| Inndotec Limited | Professional & scientific | 1976 |
| Innovative Design and Developments Limited | Extraterritorial | 2004 |
| Input Marketing Ltd | Wholesale & retail | 2020 |
| Inset Media Ltd | Information & communication | 2021 |
| Installation Squad Ltd | Administrative & support | 2012 |
| Integrity at Work Ltd | Extraterritorial | 2020 |
| International Air Cadet Training | Education | 2010 |
| Invicta Capital Holdings Ltd | Real estate | 2014 |
| Invicta Community Leisure CIC | Education | 2023 |
| Invicta Insulation Limited | Construction | 2013 |
| Invicta Investments Limited | Professional & scientific | 2001 |
| Invicta Roofing & Building Limited | Construction | 2022 |
| Invictus Heating Limited | Construction | 2017 |
| ION Partners Ltd | Information & communication | 2019 |
| Iona - Kent and South East Limited | Administrative & support | 2004 |
| Iona Healthcare Ltd | Health & social care | 2024 |
| IPA Group Ltd | Professional & scientific | 2020 |
| Ipanema Property Developments Ltd | Real estate | 2023 |
| Isco Property Partners Ltd | Real estate | 2020 |
| It.Eu (UK) Ltd | Real estate | 2011 |
| IVY MAY Fashion and Home Limited | Wholesale & retail | 2018 |
| Ivydene Mansions Freehold Limited | Real estate | 2016 |
| J Gill Homes Ltd | Real estate | 2020 |
| J M R Logistics (Kent) Ltd | Transport & logistics | 2010 |
| J Prior Limited | Construction | 2020 |
| J Simpson Interiors Ltd | Construction | 2016 |
| J T Telecommunication Ltd | Construction | 2020 |
| J Trickey Limited | Information & communication | 2018 |
| J&Dgoods Ltd | Wholesale & retail | 2024 |
| J&J Extensions Ltd | Other services | 2025 |
| J&J Kare Limited | Real estate | 2014 |
| J&J Southeast Brickwork Limited | Construction | 2024 |
| J&S Project Services Ltd | Construction | 2024 |
| J. E. Tree Surgery Limited | Arts & recreation | 2003 |
| J.A.R. Properties Kent Limited | Real estate | 2020 |
| J.C. Traffic Solutions Limited | Construction | 2005 |
| JA Macfarlane Ltd | Construction | 2019 |
| JA Services Kent Limited | Construction | 2023 |
| Jaagu Ltd | Real estate | 2021 |
| Jabbyco Ltd | Real estate | 2021 |
| JAC Plumbing Limited | Construction | 2010 |
| Jack Raven Bushcraft Ltd | Arts & recreation | 2011 |
| JACOBW52 Ltd | Information & communication | 2022 |
| Jagali Pubs Limited | Hospitality | 2019 |
| James Baker Live Ltd | Arts & recreation | 2018 |
| James Baker Productions Limited | Arts & recreation | 2011 |
| James Lewis Developments Limited | Construction | 2001 |
| Jameson Mortgage Solutions Limited | Financial services | 2006 |
| Jamiephillipsfit Limited | Arts & recreation | 2025 |
| Jamiiin Property Investments Limited | Real estate | 2015 |
| Jams Holdings Ltd | Financial services | 2025 |
| Jasmine at Home Ltd | Manufacturing | 2020 |
| JAY Benz Integrated Services Limited | Health & social care | 2025 |
| Jaytee Biosciences Limited | Manufacturing | 1987 |
| Jazz Westie Ltd | Other services | 2024 |
| JB Fire and Security Ltd | Construction | 2023 |
| JBP Projects Ltd | Professional & scientific | 2010 |