| Health and Holistics Well-Being Ltd | Wholesale & retail | 2023 |
| Healthcare Direct Limited | Wholesale & retail | 2001 |
| Healthium Medtech UK Limited | Manufacturing | 2007 |
| Healthy Living 2015 Limited | Wholesale & retail | 2015 |
| Healthywell Ltd | Health & social care | 2023 |
| Heart of Torbay CIC | Wholesale & retail | 2018 |
| Heart to Art Ltd | Wholesale & retail | 2026 |
| Hearts Investments Limited | Administrative & support | 2003 |
| Heat Well Services Ltd | Construction | 2021 |
| Heat-A-Home Ltd | Construction | 2024 |
| Heath Court (Big Block) RTM Company Limited | Households | 2023 |
| Heath Court (Small Block) RTM Company Limited | Households | 2023 |
| Heath Productions Ltd | Information & communication | 2023 |
| Heatham House Management Limited | Households | 1997 |
| Heathway Court (Hampstead) Limited | Administrative & support | 1996 |
| Hecny Forwarding Limited | Transport & logistics | 1992 |
| Hecny Freight Limited | Transport & logistics | 1951 |
| Hecny Logistics Limited | Transport & logistics | 2018 |
| Hecny Properties Limited | Real estate | 2020 |
| Hector Millhouse Limited | Professional & scientific | 2024 |
| Hector Productions Ltd | Information & communication | 2018 |
| Hedge Real Estate LLP | | 2019 |
| Helana Consulting Co. Ltd | Wholesale & retail | 2018 |
| Helgrom UK Ltd | Wholesale & retail | 2026 |
| Helion FM Ltd | Construction | 2026 |
| Hellebo Consulting Ltd | Professional & scientific | 2023 |
| Hellingly (Hailsham) Management Company Ltd | Households | 2018 |
| Hello OWL Ltd | Real estate | 2015 |
| Helma Building Construction Limited | Construction | 2025 |
| Help IS Here NOW CIC | Hospitality | 2025 |
| Help Properties Ltd | Real estate | 2024 |
| HEM Altamimi Limited | Real estate | 2019 |
| Hemingway Forward Limited | Agriculture & fishing | 2009 |
| Hemingway Projects Limited | Professional & scientific | 2015 |
| Hemini Limited | Information & communication | 1994 |
| Hemini Properties Ltd | Real estate | 2024 |
| Hemming Capital Limited | Wholesale & retail | 2016 |
| HEN and Stag Events Ltd | Other services | 2017 |
| Henderson Court Residents Company Limited | Households | 1999 |
| Hendon Homes Ltd | Real estate | 2020 |
| Henika Investments Limited | Real estate | 2015 |
| Henika Limited | Construction | 2013 |
| Henri&S Ltd | Real estate | 2024 |
| Henry Developments 2 Limited | Construction | 2025 |
| Henry Developments Ltd | Construction | 2015 |
| Henry Smith Construction Solutions Ltd | Construction | 2019 |
| Herb Palmer Ltd | Manufacturing | 2016 |
| Herber Ltd | Other services | 2019 |
| Herbert Lewis Ltd | Professional & scientific | 2026 |
| Hereford Endocrinology & Medical Services Limited | Real estate | 2019 |
| Heritagedaily Ltd | Information & communication | 2020 |
| Heritus Holdings Ltd | Construction | 2022 |
| Heritus Management Limited | Financial services | 2022 |
| Hermia Limited | Information & communication | 2010 |
| Heronclose Limited | Households | 2008 |
| Herons Court (Radlett) Management Limited | Other services | 2012 |
| Heronslea (Brookshill) Limited | Administrative & support | 2014 |
| Heronslea (Freeholds) Limited | Administrative & support | 2009 |
| Heronslea (Patchetts) Limited | Administrative & support | 2015 |
| Heronslea Group Limited | Administrative & support | 2007 |
| Heronslea Limited | Administrative & support | 2002 |
| Hertfordshire Aquatics | Education | 2018 |
| Hertfordshire Garden Design Limited | Administrative & support | 2010 |
| Hertfordshire Rheumatology Clinic Limited | Health & social care | 2014 |
| Herts Build Limited | Construction | 2019 |
| Herts Cars Borehamwood Limited | Transport & logistics | 2018 |
| Herts Health Consulting Ltd | Professional & scientific | 2025 |
| Herts HIP, Knee and Sports Injury Clinic Ltd | Health & social care | 2024 |
| Hertsclearance Limited | Wholesale & retail | 2026 |
| Hertslife Ltd | Administrative & support | 2014 |
| Hertsmere Developments Limited | Construction | 2016 |
| Hertsmere Forum of Faiths | Other services | 2011 |
| Hertsmere Homes Limited | Real estate | 2017 |
| Hertsmere Mews (Borehamwood) Management Company Limited | Real estate | 2017 |
| Hertsmere Technologies Ltd | Information & communication | 2024 |
| Hertsmere Times Limited | Real estate | 2019 |
| Hertswood Academy | Education | 2012 |
| Hesp Consulting Ltd | Information & communication | 2018 |
| Heterodocs Ltd | Information & communication | 2018 |
| Hetztronics Ltd | Manufacturing | 2025 |
| Hewitt Venture Group Ltd | Real estate | 2015 |
| Hewitts Consulting Limited | Administrative & support | 2002 |
| Heyday Films Limited | Information & communication | 1996 |
| Heymarc Limited | Administrative & support | 2025 |
| HF Holidays (Transport) Limited | Transport & logistics | 2019 |
| HF Properties LLP | | 2012 |
| HF2 Limited | Arts & recreation | 2023 |
| HFD Rights Ltd. | Administrative & support | 2013 |
| HGD Construction Ltd | Construction | 2026 |
| HGV Project Ltd | Transport & logistics | 2016 |
| HH (Hampshire) Ltd | Hospitality | 2026 |
| HH Group Holdings Limited | Construction | 2026 |
| HH Interim CFO Limited | Professional & scientific | 2014 |
| HH Team Ltd | Construction | 2020 |
| Hh-Sre Ltd | Professional & scientific | 2016 |
| Hhack Developments Ltd | Real estate | 2021 |
| Hhack Engineering Ltd | Professional & scientific | 2019 |
| Hhack Investments Ltd | Real estate | 2022 |
| HI Homes Limited | Real estate | 2016 |
| HI5 Investment Ltd | Real estate | 2021 |