| H.A.P Communications Ltd | Administrative & support | 2020 |
| H.A.S Group Ltd | Extraterritorial | 2024 |
| H.A.S. Scaffold Ltd | Extraterritorial | 2024 |
| H.B Peka Limited | Construction | 2025 |
| H.B. & F.Y. Limited | Financial services | 2024 |
| H.Boss Ltd | Real estate | 2021 |
| H.E.M Hair Ltd | Other services | 2023 |
| H.G.O Investment Limited | Construction | 2017 |
| H.Morris Smith(Jewellers)Limited | Wholesale & retail | 1959 |
| H.P.A Distributions Ltd | Financial services | 2022 |
| H20SKI Ltd | Administrative & support | 2020 |
| H2O Services Northampton Ltd | Administrative & support | 2025 |
| H2S Cars Ltd | Transport & logistics | 2023 |
| H2Z Holdings Ltd | Hospitality | 2025 |
| H3O Group Ltd | Manufacturing | 2015 |
| HA Global Trading Limited | Wholesale & retail | 2026 |
| HA Mahalo Limited | Professional & scientific | 2012 |
| Habito Management Ltd | Real estate | 2020 |
| Hackerson Limited | Extraterritorial | 2011 |
| Hackney Fresh Ltd | Wholesale & retail | 2014 |
| Haddiction Ltd | Wholesale & retail | 2024 |
| Haddon Developments Limited | Construction | 1985 |
| Haddoncraft Limited | Extraterritorial | 1991 |
| Haddongate Ltd | Arts & recreation | 2018 |
| Haddonstone Limited | Manufacturing | 1986 |
| Haden Home Management Ltd | Hospitality | 2022 |
| Haden Homes Limited | Real estate | 2017 |
| Hadi Communications Ltd | Wholesale & retail | 2020 |
| Hadi Logistic Services Ltd | Transport & logistics | 2025 |
| Hadigy Limited | Professional & scientific | 2009 |
| Hadland Commercial Surveyors Limited | Other services | 2011 |
| Hadrian 1 Ltd | Real estate | 2024 |
| Hadrian 2 Ltd | Real estate | 2024 |
| Hadrian 3 Ltd | Real estate | 2025 |
| Hadrian Ltd | Real estate | 2023 |
| Hadrys Limited | Wholesale & retail | 2012 |
| HAI Robotics U.K. Limited | Manufacturing | 2022 |
| Haider Goods & Co. Ltd | Wholesale & retail | 2026 |
| Haig's Drains Ltd | Water & waste | 2018 |
| Haipa Ltd | Transport & logistics | 2025 |
| Hair @ the Style Exchange Ltd Limited | Other services | 2015 |
| Hair Beauty Fabrique Ltd | Other services | 2025 |
| Hair by Broadway Ltd | Other services | 2026 |
| Hair by Hannah Limited | Other services | 2017 |
| Hair Extensions by Lala Ltd | Other services | 2026 |
| Hair for YOU Salon Ltd | Other services | 2023 |
| Hair NOW Ltd | Other services | 2009 |
| Hair OFF the Hounds Limited | Administrative & support | 2022 |
| Hair Science (Towcester) Ltd | Other services | 2017 |
| Hairby Nirvana Limited | Other services | 2024 |
| Hairbylauran Ltd | Other services | 2023 |
| Hakim Supermarket Ltd | Wholesale & retail | 2022 |
| Halcrow Property Management Limited | Real estate | 1994 |
| Halcyon Care (South Midlands) Ltd | Administrative & support | 2024 |
| Haldenby Care Ltd | Health & social care | 2021 |
| Halder Holdings Limited | Real estate | 2018 |
| Hale Marketing Services (Northampton) Limited | Professional & scientific | 2014 |
| Halers Lighting Limited | Extraterritorial | 2009 |
| Halexo Limited | Information & communication | 2025 |
| Halfway Down Limited | Information & communication | 2021 |
| Halheid Solutions Ltd | Professional & scientific | 2022 |
| Halica Limited | Hospitality | 2022 |
| Halili Construction Ltd | Construction | 2024 |
| Halim Consultancy Ltd | Health & social care | 2012 |
| Haliq and Grey Ltd | Real estate | 2016 |
| Hallam Floors Ltd | Wholesale & retail | 2020 |
| Hallett Brown Consultancy Limited | Professional & scientific | 2007 |
| Hallett Legal Limited | Professional & scientific | 2021 |
| Hallmark Hotels (Flitwick) Limited | Hospitality | 2006 |
| Hallmark Hotels (NO. 9) Limited | Financial services | 2013 |
| Halls Auto Services Ltd | Wholesale & retail | 2020 |
| Hallstone Brickwork Limited | Construction | 2016 |
| Hallstone Homes Limited | Construction | 2019 |
| Halo (CB) Limited | Administrative & support | 2025 |
| Halo Kitchens Ltd | Wholesale & retail | 2021 |
| Halo Property Maintenance Ltd | Construction | 2022 |
| Halo Security Solutions (UK) Limited | Administrative & support | 2012 |
| Halo Self Store Ltd | Transport & logistics | 2025 |
| Halt Capital Ltd | Real estate | 2024 |
| Hamford Properties Limited | Real estate | 2021 |
| Hamford Services Limited | Financial services | 2017 |
| Hamilton Building Contracts Ltd | Construction | 2024 |
| Hamilton Minibus Ltd | Transport & logistics | 2025 |
| Hamilton PS Ltd | Information & communication | 2025 |
| Hamilton RAI Ltd | Professional & scientific | 2020 |
| Hamli Contracting Solutions Limited | Manufacturing | 2015 |
| Hammer and Heart Ltd | Manufacturing | 2025 |
| Hammer Engineering Ltd | Manufacturing | 2017 |
| Hammer Squad Construction Ltd | Construction | 2024 |
| Hammond Catering Limited | Hospitality | 2010 |
| Hampaws Ltd | Wholesale & retail | 2024 |
| Hampden House MGT Ltd | Households | 2019 |
| Hampshire Speed and Marine Limited | Professional & scientific | 2023 |
| Hampstead Investment Group Ltd | Real estate | 2022 |
| Hampton (Burlington Court Care) Ltd | Real estate | 1976 |
| Hampton (Burlington Court) Ltd | Real estate | 2017 |
| Hampton (Midland Care) Ltd | Health & social care | 2017 |
| Hampton (Midland) Ltd | Real estate | 2017 |
| Hampton (ST Edmunds View) Ltd | Real estate | 2018 |
| Hampton (Woburn Sands Emporium) Ltd | Wholesale & retail | 2018 |