| Holdings SA Ltd | Real estate | 2023 |
| Holgate Electrical Ltd | Construction | 2022 |
| Home EV Charger Ltd | Construction | 2021 |
| Hope Contractors Ltd | Construction | 2026 |
| Hope Inns (Sussex) Limited | Construction | 2015 |
| Hosny Limited | Administrative & support | 2016 |
| House of Therapies Ltd | Administrative & support | 2016 |
| House to Home Removals Services Ltd | Transport & logistics | 2021 |
| Hovid Pharma UK Ltd | Wholesale & retail | 2022 |
| Howells-Barby Ventures Ltd | Professional & scientific | 2019 |
| Howorth Westbury Holdings Limited | Professional & scientific | 2009 |
| Howorth Westbury Properties Limited | Real estate | 2010 |
| HR Smart Limited | Professional & scientific | 2004 |
| Hubbard Fisheries Ltd | Agriculture & fishing | 2018 |
| Hudjo Ltd | Transport & logistics | 2019 |
| Hurst Fusion Ltd | Real estate | 2021 |
| HUW Hughes Limited | Arts & recreation | 2016 |
| HWE Mechanical Services Limited | Construction | 2019 |
| HWE Services (3 Hillside) Limited | Real estate | 2017 |
| Hyke Outdoors Ltd | Financial services | 2025 |
| Hypercloud Holdings Ltd | Financial services | 2024 |
| Hypercloud Properties Ltd | Real estate | 2022 |
| IAN Denman Trading Ltd | Construction | 2025 |
| Ibiza Boat Charter Limited | Arts & recreation | 2023 |
| Icon Brands Ltd | Administrative & support | 2012 |
| Iconic Lines Limited | Information & communication | 2016 |
| IF Ollie Ltd | Arts & recreation | 2024 |
| IGLOO3 Ltd | Administrative & support | 2010 |
| Igniting the Sparks Limited | Information & communication | 2017 |
| Ihowz Association | Other services | 2009 |
| Impact Group Logistic Ltd | Transport & logistics | 2020 |
| Imperial Blue Cleaning Services Ltd | Administrative & support | 2024 |
| IN the Red Golf Limited | Wholesale & retail | 2023 |
| Inch by Inch Cut's Ltd | Other services | 2019 |
| Incursion Events Ltd | Arts & recreation | 2024 |
| Independent Energy Limited | Mining & quarrying | 2019 |
| Independent Lifestyles Supplementary Services LLP | | 2012 |
| Independent Lifestyles Support Services LLP | | 2007 |
| Infinite Studio Ltd | Information & communication | 2019 |
| Information Technology Recycling Solutions Limited | Other services | 2024 |
| Inkreadible Labels Limited | Manufacturing | 2010 |
| Inline UK Group Ltd | Extraterritorial | 2005 |
| Innicle Limited | Information & communication | 2019 |
| Innovate Live Ltd | Information & communication | 2018 |
| Innvoke Ltd | Information & communication | 2025 |
| Inside Technical Limited | Professional & scientific | 2019 |
| Interactive Technologies Ltd | Information & communication | 2019 |
| International Life-Saving Appliance Manufacturers` Association | Other services | 2008 |
| International Property & Leasing Ltd | Real estate | 2004 |
| International Property Enterprise Limited | Real estate | 2004 |
| Intrinsic Marketing Limited | Professional & scientific | 2021 |
| Ireland Consultancy Ltd | Wholesale & retail | 2024 |
| Irresistible Headdresses Limited | Manufacturing | 2004 |
| Isaac FRY Consultancy Ltd | Professional & scientific | 2025 |
| ITR Commercial Limited | Wholesale & retail | 2025 |
| J C Aldred Services Ltd | Construction | 2010 |
| J Dale Services Ltd | Real estate | 2024 |
| J&B Property Group Ltd | Real estate | 2021 |
| J&H Automotive(Uk) Limited | Wholesale & retail | 2025 |
| J'S Barber Parade Ltd | Other services | 2025 |
| J. Phillips Scaffolding Services Ltd | Construction | 2018 |
| J2A Limited | Wholesale & retail | 2022 |
| Jalley Rail Limited | Construction | 2016 |
| James & James Commercial Ltd | Real estate | 2021 |
| James & James Estate Agents Ltd | Real estate | 2020 |
| James & James Holdco Ltd | Financial services | 2023 |
| James & James Lettings Ltd | Real estate | 2023 |
| Jarretts Corporation Ltd | Financial services | 2024 |
| Jarretts Driving School Limited | Education | 2017 |
| Jarretts Property Group Ltd | Real estate | 2024 |
| JB Elec Services Ltd | Construction | 2022 |
| Jb's Clearance & Maintenance Limited | Water & waste | 2016 |
| JCW Electrical & Solar Ltd | Construction | 2024 |
| JD & SON Estates Ltd | Real estate | 2024 |
| JD Driveways Ltd | Construction | 2024 |
| JE Andrews Property Ltd | Real estate | 2024 |
| Jellimanagement Ltd | Professional & scientific | 2024 |
| Jellywall Ltd | Information & communication | 2018 |
| Jemisys Limited | Professional & scientific | 2012 |
| Jets Consulting Ltd | Administrative & support | 2018 |
| Jhmiah Ltd | Other services | 2022 |
| JJ Lovett Services Ltd | Professional & scientific | 2021 |
| Jk's Food & Wine Ltd | Wholesale & retail | 2017 |
| JL Systems Ltd | Information & communication | 2025 |
| JLS Investment Properties Ltd | Real estate | 2020 |
| JMA Electrical Contractors Limited | Construction | 2016 |
| JND Marketing Limited | Manufacturing | 2022 |
| Joden Construction Ltd | Construction | 2018 |
| John Newbery Limited | Manufacturing | 1989 |
| John Pauls Barbershop Ltd | Other services | 2022 |
| John Weaver Limited | Manufacturing | 2003 |
| Johnny Dawes Movement Limited | Wholesale & retail | 2015 |
| JON Hunt Digital Ltd | Professional & scientific | 2024 |
| Jona Property Ltd | Real estate | 2013 |
| Jonnynetworks Ltd | Information & communication | 2014 |
| Joseph Jayne Developments Ltd | Real estate | 2023 |
| Joseph Jayne Group Ltd | Financial services | 2025 |
| Jpsk Ltd | Professional & scientific | 2024 |
| JRD Store Online Ltd | Wholesale & retail | 2025 |
| JRP Projects (Southern) Limited | Construction | 2016 |