| Hisco Services Limited | Professional & scientific | 2004 |
| HMK Bakeries Ltd | Wholesale & retail | 2025 |
| Hoads Farm Limited | Agriculture & fishing | 2005 |
| HOC AGE Management Services Limited | Professional & scientific | 2023 |
| Hole Park Developments Limited | Agriculture & fishing | 2006 |
| Holla Collective Limited | Real estate | 2025 |
| Home Counties Renewables Limited | Construction | 2025 |
| Home Gurrown Limited | Hospitality | 2009 |
| Hortus Creative Landscapes Limited | Administrative & support | 2026 |
| House Martin Investments Ltd | Real estate | 2024 |
| House of Odunje Ltd | Hospitality | 2025 |
| Housemartin (UK) Limited | Construction | 2014 |
| HQ Creative Ltd | Real estate | 2023 |
| HR Estate Planning Limited | Professional & scientific | 2020 |
| HRX Limited | Administrative & support | 2009 |
| HSP Hire & STR Ltd | Professional & scientific | 2018 |
| Hunu Limited | Hospitality | 2014 |
| Hurst Green Holdings Limited | Real estate | 2022 |
| Hutsons Court Management Company Limited | Households | 1986 |
| HVH Capital Limited | Financial services | 2015 |
| HVN Limited | Construction | 2022 |
| Hybert Design Limited | Professional & scientific | 2006 |
| Hydrosphere Charters Ltd | Transport & logistics | 2020 |
| Hydrosphere Innovations Ltd | Administrative & support | 2012 |
| IAN Osborne Design Ltd | Arts & recreation | 2017 |
| IB Books and Credits Ltd | Professional & scientific | 2020 |
| Idenhurst Ltd | Real estate | 2022 |
| Igor ADV Ltd | Professional & scientific | 2024 |
| Immersives Group Ltd | Information & communication | 2023 |
| Imperial Hygiene (United Kingdom) Ltd | Extraterritorial | 2014 |
| Imperial Hygiene Services Limited | Administrative & support | 2002 |
| IN Design Kitchens Ltd | Manufacturing | 2025 |
| Inchware Limited | Real estate | 2000 |
| Indigo Shading Ltd | Construction | 2023 |
| Indigo Shading Solutions Limited | Wholesale & retail | 2011 |
| Infinity Construction & Design Limited | Construction | 2019 |
| Instadoggo Ltd | Information & communication | 2022 |
| Institute of Pharmacy Management International Limited (the) | Other services | 1964 |
| Integrated Solutions Limited | Information & communication | 1989 |
| Interim Advisory Services Limited | Professional & scientific | 2018 |
| International Consulting and Partners Limited | Information & communication | 2014 |
| Intervention Workforce Solutions Ltd | Professional & scientific | 2020 |
| Intimacy on SET Ltd | Other services | 2018 |
| Intimates Lingerie Limited Liability Partnership | | 2007 |
| Intrel Ltd | Professional & scientific | 2023 |
| Invicta Stamps Limited | Wholesale & retail | 2018 |
| Inyama Biltong Ltd | Manufacturing | 2022 |
| IRI Multi Resources UK Limited | Wholesale & retail | 2022 |
| ISC Tree Specialist Limited | Agriculture & fishing | 2004 |
| Issey Moloney Ltd | Information & communication | 2022 |
| J a Rose Storage Limited | Real estate | 2019 |
| J. P. Joinery (Kent) Limited | Construction | 2009 |
| J.P. Gooderson Ltd | Transport & logistics | 2026 |
| J2 Automation Ltd | Professional & scientific | 2025 |
| JA Classic and Sports Limited | Extraterritorial | 2017 |
| JA Roofing & Construction Limited | Construction | 2024 |
| JAE Consulting Limited | Professional & scientific | 2018 |
| James Law Developments Limited | Real estate | 2018 |
| Jarvis Land (South East) Limited | Construction | 2016 |
| Jarvis Land Promotions Ltd | Professional & scientific | 2020 |
| Jarvis Properties Ltd | Financial services | 2020 |
| Jarvis Strategic Land Limited | Construction | 2017 |
| JBM Auto Services Limited | Wholesale & retail | 2017 |
| Jbsw Engineering Ltd | Construction | 2019 |
| JDH Fine Furnishings Limited | Manufacturing | 2023 |
| JDH Soft Furnishings Ltd | Manufacturing | 2019 |
| JDT Tuning Ltd | Wholesale & retail | 2018 |
| JEM Sports and Media Management Limited | Other services | 2005 |
| JEM Sports Holdings Limited | Financial services | 2025 |
| Jenny Edbrooke Ltd | Education | 2018 |
| Jeremy Forty Consulting Ltd. | Professional & scientific | 2014 |
| Jessie V E Ltd | Manufacturing | 2015 |
| JFX Enterprises Limited | Administrative & support | 2014 |
| JIM Henson Productions Limited | Information & communication | 1979 |
| JKM Solutions Limited | Information & communication | 1999 |
| JM Wine Consulting Ltd | Professional & scientific | 2021 |
| Jmcd Consultancy Limited | Professional & scientific | 2025 |
| JMF Trading Technology Solutions Ltd | Information & communication | 2024 |
| JMK Edwards Ltd | Professional & scientific | 2019 |
| JN Financial Consulting Ltd | Professional & scientific | 2024 |
| Jobvia Ltd | Information & communication | 2026 |
| John Bourne & Co. Ltd. | Manufacturing | 1959 |
| John Wickham (Cranbrook) Limited | Agriculture & fishing | 1986 |
| Jones Cubed Limited | Administrative & support | 2017 |
| Jplm Painters & Decorators Ltd | Construction | 2023 |
| JR Group Assets & Acquisitions Ltd | Real estate | 2026 |
| JR Group Assets & Investments Ltd | Real estate | 2026 |
| Jubilee Hire Limited | Hospitality | 2015 |
| Jwrc Limited | Financial services | 2023 |
| K K Electrical (South East) Limited | Construction | 2002 |
| K8EDW Limited | Professional & scientific | 2001 |
| Kambara Limited | Other services | 2008 |
| KAP Essential Services Ltd | Transport & logistics | 2019 |
| Kate Warner Tech Limited | Information & communication | 2021 |
| Katherine Paul Ltd | Information & communication | 2011 |
| KE Consult Ltd | Professional & scientific | 2025 |
| Keith Hollands Limited | Professional & scientific | 2006 |
| Kellievison Limited | Information & communication | 2006 |
| Kemp Scaffolding Limited | Construction | 2003 |
| Kent and East Sussex Railway Adventures Company Limited | Manufacturing | 2017 |