| Hedlyn Building Contractors Limited | Construction | 2018 |
| Henry's Decoration & Restoration Ltd | Construction | 2022 |
| Hereford Saxon Ltd | Wholesale & retail | 2025 |
| Heritage Electrics (Blaenavon) Limited | Administrative & support | 2016 |
| Heritage Funeral Service Limited | Other services | 2012 |
| Hermitage Electricals Ltd | Construction | 2004 |
| Hewitts Wave Ltd | Wholesale & retail | 2025 |
| High & DRY Roofing & Building Ltd | Construction | 2025 |
| Highstreet Fitness Limited | Arts & recreation | 2020 |
| Hill & Hill Consulting Limited | Real estate | 2019 |
| Hillier Heritage Ltd | Hospitality | 2025 |
| Hillside Fish & Cafe Bar Ltd | Hospitality | 2024 |
| Hive: ‘Happy Individuals Venture Everywhere’. Community Interest Company | Education | 2026 |
| Holburn Knaive Ltd | Wholesale & retail | 2025 |
| Home Heating Team Ltd | Construction | 2026 |
| Honey BEE Cwtch Ltd | Hospitality | 2025 |
| Hope Property Group Ltd | Real estate | 2021 |
| Horrel Brays Ltd | Wholesale & retail | 2025 |
| Horseland CIC | Arts & recreation | 2011 |
| Horseshoe Property Lettings Limited | Real estate | 2025 |
| HOW to BE Brilliant Limited | Professional & scientific | 2023 |
| Howard Properties One Limited | Real estate | 2024 |
| Howards Shirley Ltd | Wholesale & retail | 2025 |
| Hsiang Yang Flower Limited | Hospitality | 2003 |
| HSM Football Limited | Arts & recreation | 2024 |
| Hutton Clay Ltd | Wholesale & retail | 2025 |
| Hydd Property Management Ltd | Real estate | 2020 |
| Hyde Gurney Ltd | Wholesale & retail | 2025 |
| I CAN Education Ltd | Education | 2021 |
| I Want 123 Limited | Manufacturing | 2017 |
| I.E. Precision Flooring Ltd | Construction | 2020 |
| IAB Rail Ltd | Construction | 2016 |
| IAN Lawrenson Fencing Limited | Administrative & support | 2003 |
| Ican Hub CIC | Education | 2025 |
| ID Projects Consultancy Limited | Construction | 2011 |
| Iliana Developments Ltd | Real estate | 2025 |
| Image Occupied Territory Ltd | Professional & scientific | 2010 |
| Imagist International Limited | Health & social care | 2015 |
| Imagist Properties Limited | Real estate | 2021 |
| Impala Gardens Ltd | Wholesale & retail | 2025 |
| IMY Ltd | Construction | 2020 |
| IN OUR Nature CIC | Health & social care | 2019 |
| Industrial Battery Services Ltd | Manufacturing | 2015 |
| Industrial Engineering Services (UK) Ltd | Manufacturing | 2006 |
| Inspek QA Limited | Professional & scientific | 2009 |
| Installation Professional Ltd | Construction | 2024 |
| International Waste Recycling Ltd | Water & waste | 2019 |
| ION Electrical Solutions Ltd | Construction | 2026 |
| Ircobalt Ltd | Wholesale & retail | 2022 |
| Itani Holdings Ltd | Real estate | 2020 |
| Itchen Canner Ltd | Wholesale & retail | 2025 |
| Izmir(Npt) Ltd | Other services | 2026 |
| J & T Motor Traders Ltd | Extraterritorial | 2023 |
| J and J Commercial Body Repairs Limited | Wholesale & retail | 2025 |
| J B Painting Limited | Construction | 2008 |
| J Haggerty & Co Holdings Ltd | Financial services | 2025 |
| J Holloway Co Ltd | Professional & scientific | 2022 |
| J Kennedy Metals Ltd Ltd | Wholesale & retail | 2015 |
| J P Powell Building Contractor Limited | Construction | 2024 |
| J&E Colourcoat Limited | Manufacturing | 2018 |
| J&J Kennedy Demolition Ltd | Construction | 2020 |
| J&J Kennedy Metals Ltd | Wholesale & retail | 2021 |
| J.W Vent Ltd | Construction | 2026 |
| J2R Demolition Limited | Construction | 2017 |
| Jack of ALL Trades Ltd | Construction | 2019 |
| Jackie Cobblers Ltd | Wholesale & retail | 2024 |
| Jackman & Company Consultants UK Limited | Professional & scientific | 2025 |
| Jacob's Van Upgrades Ltd | Wholesale & retail | 2017 |
| James Austin & Co Ltd | Other services | 2023 |
| James Wallas Ltd | Construction | 2023 |
| Jarrat Sheaves Limited | Wholesale & retail | 2025 |
| Jarvis Property Lets Limited | Real estate | 2025 |
| Javelin Dakota Ltd | Wholesale & retail | 2025 |
| Jayne's Baby Bank C.I.C. | Other services | 2025 |
| JB Electrical & Sons Ltd | Construction | 2024 |
| JD Parfitt Mortgages Ltd | Financial services | 2025 |
| Jean Properties Ltd | Real estate | 2025 |
| Jefflyn Construction Limited | Construction | 1990 |
| Jeffries Construction Limited | Construction | 2014 |
| Jellybeans Child Minders Ltd | Health & social care | 2025 |
| Jenna Louise Cakes & Bakes Ltd | Manufacturing | 2021 |
| Jenson Travel Limited | Transport & logistics | 2015 |
| Jess Willow Holdings Ltd | Financial services | 2021 |
| Jessica Roberts Communications Ltd | Professional & scientific | 2021 |
| JET Training Services (2022) Ltd | Education | 2022 |
| Jetforce 247 Limited | Administrative & support | 2026 |
| Jillcot Valleys Ltd | Wholesale & retail | 2025 |
| JJ Digital Media Ltd | Information & communication | 2026 |
| JK Metal Art Ltd | Professional & scientific | 2021 |
| JKL Book-Keeping Limited | Professional & scientific | 2018 |
| JM Bowen Plant & Groundworks Ltd | Construction | 2025 |
| JM Quarry Services Ltd | Mining & quarrying | 2018 |
| JMA Auto Ltd | Wholesale & retail | 2022 |
| Jocelyn Manx Ltd | Wholesale & retail | 2025 |
| Jockey Garage Limited | Wholesale & retail | 2002 |
| Joe's Landscaping & Tree Services Ltd | Administrative & support | 2026 |
| John-Ross COX Ltd | Hospitality | 2025 |
| Johnsey Estates 2020 Ltd | Real estate | 2020 |
| Johnsey Estates Limited | Professional & scientific | 1970 |
| Johnsey Estates Property Holdings Limited | Real estate | 2020 |