| HCI Mercantile Holdings (UK) Ltd | Professional & scientific | 2021 |
| HCP Property Limited | Real estate | 2021 |
| HD & JP Limited | Professional & scientific | 2010 |
| HD Card Services Limited | Administrative & support | 2013 |
| HD Cardiff Limited | Hospitality | 2016 |
| HD Consultantcy Limited | Information & communication | 2015 |
| HD Developments Sussex Ltd | Construction | 2024 |
| HD Dynamics Ltd | Education | 2013 |
| HD Entertain Limited | Administrative & support | 2023 |
| HD Hand Surgery Limited | Health & social care | 2020 |
| HD Home Developments Ltd | Real estate | 2024 |
| HD Hughes Ltd | Professional & scientific | 2020 |
| HD Mart Ltd | Wholesale & retail | 2026 |
| HD Pictures Limited | Other services | 2008 |
| HD Pinfold Properties Ltd | Real estate | 2025 |
| HD Recruitment Limited | Administrative & support | 2017 |
| HD Store Ltd | Wholesale & retail | 2025 |
| Hd&Jp Holdings Limited | Financial services | 2022 |
| HDE Medical Limited | Health & social care | 2022 |
| Hdidi Ltd | Information & communication | 2020 |
| HDK Distribution Ltd | Wholesale & retail | 2023 |
| HDK Limited | Transport & logistics | 2025 |
| HDM Alliance Ltd | Wholesale & retail | 2018 |
| HDM Market Ltd | Wholesale & retail | 2025 |
| Hdmd Property Ltd | Real estate | 2024 |
| HDO Warehousing Limited | Wholesale & retail | 2019 |
| Hdsportwear Ltd | Manufacturing | 2025 |
| Hdvve Ltd | Administrative & support | 2021 |
| Hdwy Ltd | Arts & recreation | 2018 |
| HE London Consulting Ltd | Professional & scientific | 2018 |
| HE Oriental Express Limited | Hospitality | 2026 |
| Head and Neck Clinic Ltd | Health & social care | 2019 |
| Head Quarters Hair Transplants Limited | Health & social care | 2018 |
| Head Recruits Ltd | Administrative & support | 2018 |
| Head Threads Limited | Wholesale & retail | 2010 |
| Headford Strategic Growth Limited | Professional & scientific | 2013 |
| Headford USA Limited | Administrative & support | 2016 |
| Headington Homes Ltd | Real estate | 2021 |
| Heads Above the Waves CIC | Manufacturing | 2015 |
| Headsmart Design Ltd | Information & communication | 2015 |
| Headspin UK Limited | Information & communication | 2020 |
| Headway Cardiff and South East Wales | Health & social care | 1997 |
| Headwayai Ltd | Health & social care | 2025 |
| Headzone Hair & Beauty Limited | Other services | 2023 |
| Heakin Sales Ltd | Wholesale & retail | 2025 |
| Healcerion UK Ltd | Professional & scientific | 2022 |
| Healerr Ltd | Wholesale & retail | 2025 |
| Healing Hands Healthcare Limited | Public administration | 2024 |
| Healing West Company | Professional & scientific | 2025 |
| Health & Growth Foundation | Information & communication | 2021 |
| Health AA Ltd | Health & social care | 2023 |
| Health Analytics Consulting Ltd | Health & social care | 2021 |
| Health and HER Ltd | Wholesale & retail | 2017 |
| Health Economics and Outcomes Research Ltd | Professional & scientific | 2011 |
| Health Hayngel Ltd | Health & social care | 2014 |
| Health Holding Group Limited | Extraterritorial | 2018 |
| Health Primary Ltd | Administrative & support | 2023 |
| Health Revival Limited | Wholesale & retail | 2014 |
| Health Systems Innovation Ltd | Information & communication | 2025 |
| Healthbox Software Ltd | Wholesale & retail | 2020 |
| Healthcare 4 Africa | Professional & scientific | 2020 |
| Healthcare Academi Cymru Limited | Administrative & support | 2019 |
| Healthcare Evaluation Associates Limited | Financial services | 2020 |
| Healthcare Interact Ltd | Other services | 2012 |
| Healthcare Inventory Control Systems Limited | Professional & scientific | 2025 |
| Healthconnect Group Limited | Financial services | 2025 |
| Healthier Expert UK Ltd | Manufacturing | 2025 |
| Healthit Limited | Health & social care | 2022 |
| Healthko Limited | Health & social care | 2024 |
| Healthrite Supplements Limited | Wholesale & retail | 2021 |
| HEALTHUK2023 Ltd | Health & social care | 2025 |
| Healthwise Innovations Ltd | Information & communication | 2023 |
| Healthwise Pharmacy Group Ltd | Wholesale & retail | 2023 |
| Healthy Awareness Ltd | Health & social care | 2005 |
| Healthy Body Mobile Services Ltd | Health & social care | 2022 |
| Healthy Business Solutions Limited | Other services | 2012 |
| Healthy Eats Limited | Professional & scientific | 2019 |
| Healthy Foods Corner Ltd | Wholesale & retail | 2013 |
| Healthy Gourmet Company Limited | Real estate | 2000 |
| Healthy Investment Management Limited | Professional & scientific | 2021 |
| Healthy Life International Limited | Professional & scientific | 2009 |
| Healthy Sites Ltd | Information & communication | 2024 |
| Healy Utilities Ltd | Water & waste | 2018 |
| Healyn Ltd | Transport & logistics | 2016 |
| Hear Clear Solutions Ltd | Wholesale & retail | 2017 |
| Hearn Limited | Professional & scientific | 2013 |
| Heart & Home Services Limited | Transport & logistics | 2025 |
| Heart EYE Ltd | Wholesale & retail | 2025 |
| Heart N Design Limited | Information & communication | 2018 |
| Heart of Darkness Limited | Information & communication | 2014 |
| Heart Screening UK Limited | Health & social care | 2023 |
| Heart Stone Properties Ltd | Real estate | 2025 |
| Heart@ Group Ltd | Other services | 2025 |
| Hearth & Home Crafts Ltd | Wholesale & retail | 2025 |
| Hearth and Soul Limited | Construction | 2018 |
| Heas Instruments Limited | Wholesale & retail | 2022 |
| Heat & Control Ltd | Construction | 2019 |
| Heat & Screed Limited | Construction | 2012 |
| Heat and Power Solutions Limited | Professional & scientific | 2007 |
| Heat and Vent Wholesale Ltd | Wholesale & retail | 2022 |