| H.B. Pearce (Contractors) Limited | Construction | 1945 |
| H.B.H. Developments Limited | Financial services | 1983 |
| H.F.Hooton and Sons Limited | Wholesale & retail | 1960 |
| H4 Carpentry Limited | Construction | 2022 |
| Habs Retail Ltd | Other services | 2024 |
| Hail the Nails Limited | Administrative & support | 2013 |
| Hair @ JUNCTI8N Ltd | Other services | 2011 |
| Hair by Danni Limited | Wholesale & retail | 2016 |
| Hair, Barbers & Wellbeing at NO.68 Limited | Other services | 2021 |
| HAIRAT23 Limited | Other services | 2023 |
| Hajime Logistic Ltd | Transport & logistics | 2020 |
| Halfyard Limited | Real estate | 2019 |
| Hallerton Roofing Limited | Real estate | 2006 |
| Hallmark Electrics Limited | Administrative & support | 2013 |
| Hallmark Logistics Limited | Transport & logistics | 2002 |
| Hallmark Specialist Engineering Limited | Manufacturing | 1997 |
| Hallsten Limited | Financial services | 2018 |
| Halo Energy Ltd | Administrative & support | 2011 |
| Hamblins of Rushden Limited | Professional & scientific | 1998 |
| Hamilton Brickwork Contractors Ltd | Construction | 2016 |
| Hamilton Construction & Development Limited | Construction | 2024 |
| Hamiltons Coaches Limited | Administrative & support | 2009 |
| Hampden Test Equipment Limited | Manufacturing | 1962 |
| Hannah Mason Ltd | Manufacturing | 2026 |
| Hannavizion Limited | Information & communication | 2025 |
| Hanover (2012) Limited | Extraterritorial | 2012 |
| Hanover Consulting (Investment) Limited | Financial services | 2001 |
| Hanover Consulting (Premium) Limited | Financial services | 2002 |
| Hanover Park Investments (Ramsgate) Ltd | Real estate | 2021 |
| Hanover Park Investments Ltd | Real estate | 2019 |
| Hanover Park Property Group Ltd | Financial services | 2018 |
| Hansard Engineering Ltd | Professional & scientific | 2025 |
| Hansdavis (UK) Limited | Administrative & support | 2007 |
| Hanwood Park LLP | | 2006 |
| Hanwood Park Rangers FC CIC | Education | 2025 |
| Hapman Ltd | Health & social care | 2026 |
| Happy Haircuts by Tony Ltd | Other services | 2024 |
| Happy Hands Childcare Limited | Education | 2018 |
| Happy Living Support Ltd | Administrative & support | 2025 |
| Happy News Kettering Ltd | Wholesale & retail | 2024 |
| Harborough Packaging Ltd | Manufacturing | 2011 |
| Harbourside Collective Ltd | Wholesale & retail | 2025 |
| Hardwater Holdings Limited | Financial services | 2019 |
| Harley Stanger Plumbing and Heating Ltd | Construction | 2021 |
| Harlow (HIP) Limited | Real estate | 2024 |
| Harmer Holdings Limited | Extraterritorial | 1966 |
| Harniss Consulting Limited | Construction | 2018 |
| Harniss Contracting Limited | Construction | 2009 |
| Harris Aesthetics Ltd | Other services | 2021 |
| Harris Construction Services Limited | Professional & scientific | 2017 |
| Harrison and Co Property Developments Limited | Construction | 2019 |
| Harrison Lifestyle Ltd | Other services | 2020 |
| Harrison Supplies Limited | Wholesale & retail | 2003 |
| Harrowden Farms Developments Limited | Construction | 1993 |
| Harrowden Turf (Holdings) Limited | Financial services | 2020 |
| Harrowden Turf Limited | Agriculture & fishing | 2014 |
| Harry Bromptons Ltd | Manufacturing | 2013 |
| Hartsrose (Holdings) Ltd | Professional & scientific | 2023 |
| Harty IT Solutions Limited | Information & communication | 2025 |
| Harvey Morgan Fitness Limited | Arts & recreation | 2019 |
| Harvey Reed Top Table Limited | Extraterritorial | 1975 |
| Hauer Homes Ltd | Real estate | 2023 |
| Hawkes Demolition Limited | Construction | 2015 |
| Hawkes Developments Limited | Administrative & support | 2016 |
| Hawkes Group Ltd | Financial services | 2016 |
| Hawkes Plant Hire Ltd | Administrative & support | 2018 |
| Hawthorn Services Ltd | Hospitality | 2025 |
| Hawthorn Store Group Ltd | Wholesale & retail | 2025 |
| Hayer Investments Ltd | Real estate | 2017 |
| Hayletts Private Hire Limited | Transport & logistics | 2007 |
| Hayley Bradley Limited | Health & social care | 2025 |
| Hazel Accountancy & Business Consultancy Ltd | Professional & scientific | 2024 |
| HAZY7 Ltd. | Hospitality | 2022 |
| HD Consulting Ltd | Information & communication | 2022 |
| Headlands House Limited | Professional & scientific | 2022 |
| Health & Safety Certification & Services Limited | Administrative & support | 2009 |
| Healthy Kids Limited | Manufacturing | 2005 |
| Healthy Pet Supplies Ltd | Wholesale & retail | 2018 |
| Hearn Developments Ltd | Construction | 2026 |
| Heartland Direct Ltd | Transport & logistics | 2025 |
| Heat & Plumb Pro. Limited | Construction | 2022 |
| Heat Pump Training UK Limited | Construction | 2020 |
| Heat-Space Contracts Ltd | Construction | 2024 |
| Heath and Hawkes Limited | Manufacturing | 1980 |
| Heaysman's Heating Ltd | Construction | 2024 |
| Hedgehobbits Ltd | Manufacturing | 2024 |
| Hedley Lomas Ltd | Agriculture & fishing | 2009 |
| Hello Textiles Ltd | Wholesale & retail | 2023 |
| Hellodpo Ltd | Extraterritorial | 2023 |
| Helm Flooring Limited | Construction | 2008 |
| Helmet Head Ltd | Arts & recreation | 2024 |
| Helmut 34 Ltd | Wholesale & retail | 2024 |
| Help Around the Home Limited | Construction | 2024 |
| Hempteach Ltd | Education | 2025 |
| Hemsby Inns Limited | Hospitality | 2017 |
| Henderson Connellan (Corby) Ltd | Real estate | 2010 |
| Henderson Connellan (Kettering) Limited | Real estate | 2010 |
| Henderson Connellan Limited | Administrative & support | 1996 |
| Henderson Connellan Market Harborough Limited | Real estate | 2007 |
| Henderson Connellan Nene Valley Limited | Real estate | 2021 |