| Hayzen Consultancy Ltd | Administrative & support | 2024 |
| Hayzen Homes Ltd | Real estate | 2024 |
| Hayzen Prime Services Ltd | Administrative & support | 2024 |
| Hazard Alley Limited | Education | 2006 |
| Haze Garms Limited | Wholesale & retail | 2022 |
| Haze Luxe Ltd | Wholesale & retail | 2025 |
| Hazel Asset Limited | Financial services | 2023 |
| Hazelgrove Limited | Real estate | 2013 |
| Hazeltree Asset Management Ltd | Professional & scientific | 2020 |
| Hazeltree Care Services Ltd | Health & social care | 2017 |
| Hazeltree Housing Limited | Real estate | 2012 |
| Hazy Sea Holdings Limited | Real estate | 2016 |
| Hazy Sea Limited | Health & social care | 2015 |
| HB ENG Ltd | Professional & scientific | 2018 |
| HB Plumbing and Heating Services Ltd | Construction | 2023 |
| HB Sports Surfaces Limited | Construction | 2011 |
| HBB Trading Group Ltd | Wholesale & retail | 2024 |
| Hboxing Ltd | Arts & recreation | 2019 |
| HC Zhou Ltd. | Wholesale & retail | 2025 |
| HCB Control Solutions Limited | Construction | 2014 |
| Hcelik Strategic Solutions Ltd | Administrative & support | 2024 |
| Hcgb Housing Limited | Real estate | 2026 |
| Hcgb Services Limited | Real estate | 2020 |
| HCH Accountancy Services Limited | Professional & scientific | 1991 |
| HCI Consultancy Limited | Information & communication | 2025 |
| HCN Consulting Limited | Professional & scientific | 2013 |
| HCO Accountancy Services Limited | Professional & scientific | 2007 |
| HCP Rewards Ltd | Administrative & support | 2024 |
| HD Install & Maintenance (Northern) Ltd | Construction | 2023 |
| HD Lifeshine Ltd | Wholesale & retail | 2025 |
| Hd-Imports Ltd | Wholesale & retail | 2026 |
| HDK Solutions Ltd | Information & communication | 2008 |
| HDN Recruitment Limited | Health & social care | 2015 |
| HDS Plumbing & Heating Limited | Construction | 2018 |
| Hdss Property Ltd | Real estate | 2025 |
| HE Lives Bible Church - Glorious Church | Other services | 2011 |
| Head Held High Limited | Administrative & support | 2013 |
| Headers N Volleys Ltd | Arts & recreation | 2025 |
| Headline Audio Limited | Wholesale & retail | 2023 |
| Headline MK Limited | Manufacturing | 2012 |
| Heads and Tales Limited | Health & social care | 2021 |
| Headway Milton Keynes Limited | Health & social care | 2000 |
| Heald Solicitors LLP | | 2011 |
| Healdlaw Holdings Limited | Financial services | 2025 |
| Healdlaw Limited | Professional & scientific | 2010 |
| Healing&Beyond Ltd | Health & social care | 2025 |
| Healofy Healthcare Ltd | Health & social care | 2022 |
| Health & Aesthetics Limited | Health & social care | 2007 |
| Health & Wealth Protection Co. Ltd | Financial services | 2026 |
| Health and Aesthetics Medispa Limited | Wholesale & retail | 2012 |
| Health and Innovation Limited | Manufacturing | 2022 |
| Health Care Innovations and Services Ltd | Health & social care | 2022 |
| Health Collaborated Limited | Health & social care | 2021 |
| Health Consult Clinic Limited | Health & social care | 2023 |
| Health Consult Services Ltd | Health & social care | 2023 |
| Health Priorities Limited | Health & social care | 2019 |
| Health Recruitment UK Limited | Extraterritorial | 2012 |
| Health Serve Ltd | Health & social care | 2019 |
| Healthcare Capital Partners Limited | Financial services | 1997 |
| Healthcare Tenders Ltd | Professional & scientific | 2024 |
| Healthcrest Limited | Health & social care | 2023 |
| Healthjevity CIC | Education | 2026 |
| Healthkare Physiotherapy Limited | Health & social care | 2024 |
| Healthmed Technologies Ltd | Information & communication | 2024 |
| Healthnova Pharma Generics Ltd | Wholesale & retail | 2024 |
| Healthspan Wellness Ltd | Health & social care | 2024 |
| Healthtech Intl, Ltd | Information & communication | 2014 |
| Healthy Gift Link Ltd | Hospitality | 2025 |
| Healthy Horizons Limited | Financial services | 2010 |
| Healthy Life Solutions Limited | Health & social care | 2010 |
| Healthy Living Academy Ltd | Other services | 2024 |
| Healthy Scalp Limited | Other services | 2020 |
| Healwithnaomi Ltd | Wholesale & retail | 2024 |
| Healy Family Foundation UK Ltd | Health & social care | 2022 |
| Heargonomic Ltd | Extraterritorial | 2024 |
| Hearing Health Hub Limited | Wholesale & retail | 2020 |
| Heart of a Coward Limited | Arts & recreation | 2016 |
| Heart of Care Ltd | Health & social care | 2020 |
| Heart of Chelsea Limited | Real estate | 2019 |
| Heart of Helping Ltd | Health & social care | 2024 |
| Hearth Estates Ltd | Real estate | 2026 |
| Hearth Mortgages Ltd | Financial services | 2026 |
| Heartside Care Ltd | Health & social care | 2025 |
| Heartstone Psychiatry Ltd | Health & social care | 2026 |
| Heartview Children Homes Ltd | Health & social care | 2024 |
| Heartville Capital Ltd | Real estate | 2025 |
| Heartwood Care Solutions Limited | Health & social care | 2026 |
| Heat Lord Ltd | Construction | 2023 |
| Heat Recovery (Hvac) Limited | Energy | 2020 |
| Heatag Home Solutions Ltd | Construction | 2025 |
| Heatcycle Ltd | Other services | 2023 |
| Heath Electrical Services (HES) Ltd | Construction | 2025 |
| Heath Engineering (Bedford) Limited | Manufacturing | 1982 |
| Heath Farm Management Company Limited | Households | 2024 |
| Heath Farm Norfolk Limited | Construction | 2021 |
| Heather Aesthetics & Beauty Clinic Limited | Other services | 2024 |
| Heatherwood Limited | Information & communication | 2009 |
| Heathford Limited | Real estate | 2004 |
| Heathville Healthcare Services Limited | Health & social care | 2019 |
| Heathway Properties Limited | Real estate | 2004 |