| Hayes Music Limited | Manufacturing | 2009 |
| Hayes Rhinology Ltd | Health & social care | 2022 |
| Haygarth Ltd | Manufacturing | 2021 |
| Hayling Island Laboratories Ltd | Information & communication | 2015 |
| Haylor Limited | Other services | 2022 |
| Haynes Services Limited | Wholesale & retail | 2017 |
| Hayter Courier Services Ltd | Transport & logistics | 2019 |
| Haytham Mukhaimer Financial Consultancy Ltd | Administrative & support | 2026 |
| Hayward Metalworks Ltd | Professional & scientific | 2025 |
| Hayward’S Properties Limited | Real estate | 2026 |
| Hayyus Limited | Health & social care | 2019 |
| Hazaplan Limited | Wholesale & retail | 2016 |
| Hazardous Area Technical Training Limited | Other services | 2015 |
| Haze & Maze Ltd | Wholesale & retail | 2026 |
| Hazel Brook Brickwork Ltd | Construction | 2021 |
| Hazeleigh Property Investments Limited | Real estate | 2017 |
| Hazelhurst Project Limited | Construction | 2020 |
| Hazell&Co Ltd | Real estate | 2018 |
| Hazelnut Homes Ltd | Real estate | 2025 |
| Hazlehurst Hughes Limited | Professional & scientific | 2024 |
| HB Credit Advisory Ltd | Administrative & support | 2026 |
| HB Edits Limited | Information & communication | 2011 |
| HB Groundworks Limited | Construction | 2016 |
| HB Osteopathy Limited | Health & social care | 2019 |
| HB Partners Ltd | Administrative & support | 2025 |
| Hberry Holdings Ltd | Construction | 2025 |
| HBL Brickwork Ltd | Construction | 2017 |
| HBR Cars Ltd | Transport & logistics | 2026 |
| Hbsy Ltd | Health & social care | 2019 |
| HBT Retail Ltd | Wholesale & retail | 2026 |
| HC2B Ltd | Other services | 2023 |
| Hcexecutive Ltd | Construction | 2017 |
| HCF Group Ltd | Real estate | 2019 |
| HCG UK EU DMC Limited | Administrative & support | 2026 |
| HCH Property Holdings Ltd | Real estate | 2025 |
| Hcis Limited | Extraterritorial | 1996 |
| Hclowe Consulting Ltd | Information & communication | 2009 |
| HCR Dean Road Ltd | Households | 2007 |
| HCS Housing Ltd | Real estate | 2025 |
| HCS Safety EOT Limited | Administrative & support | 2025 |
| HCS Safety Limited | Education | 2006 |
| HD Design and Project Management Limited | Construction | 2021 |
| HD Infotech Ltd | Information & communication | 2025 |
| HD Mortgages Ltd | Financial services | 2015 |
| Hdbk Limited | Professional & scientific | 2022 |
| He-Man Dual Controls Limited | Manufacturing | 1931 |
| Head for Happy Ltd | Other services | 2024 |
| Headcorn Investments Ltd | Real estate | 2000 |
| Header Athletic Wear Limited | Wholesale & retail | 2010 |
| Headfudge Clothing Ltd | Wholesale & retail | 2019 |
| Headfudge Design Limited | Arts & recreation | 2007 |
| Headphone Revolution Limited | Wholesale & retail | 2009 |
| Heads Group Holding Limited | Financial services | 2019 |
| Heads Resourcing Group Limited | Administrative & support | 2009 |
| Heads Resourcing Trustee Company Limited | Professional & scientific | 2025 |
| Heads UP Training Services Ltd | Education | 2019 |
| HEADS2GETHER Limited | Professional & scientific | 2019 |
| Headsup TCD Limited | Information & communication | 2024 |
| Headwards Creative Studios Ltd | Professional & scientific | 2026 |
| Headway Southampton | Health & social care | 1996 |
| Healing Horizons Psychiatry Limited | Health & social care | 2025 |
| Health and Protection Solutions Limited | Financial services | 2003 |
| Health for ALL Mission CIC | Health & social care | 2024 |
| Health Hub Solutions Ltd | Health & social care | 2024 |
| Health Innovation Wessex Limited | Health & social care | 2014 |
| Health Station Foods Ltd | Hospitality | 2020 |
| Health Tech Pcists Ltd | Professional & scientific | 2025 |
| Health&Healthsciences Ltd | Professional & scientific | 2018 |
| Health/Wellness International Consultants Ltd | Health & social care | 2024 |
| Healthbridge International Ltd | Wholesale & retail | 2026 |
| Healthcare Professionals Matter TOO CIC | Information & communication | 2020 |
| Healthcare Recruitment Search and Selection Ltd | Administrative & support | 2023 |
| Healthforce Talent Limited | Administrative & support | 2026 |
| Healthpress Property Management Company Limited | Extraterritorial | 1990 |
| Healthy Design Limited | Professional & scientific | 2010 |
| Healthy Nuts Limited | Hospitality | 2017 |
| Healthy Pet Store Ltd | Wholesale & retail | 2014 |
| Healthy Relaxation Ltd | Other services | 2024 |
| Heans Legal Ltd | Professional & scientific | 2014 |
| Hearn Consulting Limited | Professional & scientific | 2020 |
| Heart & Palms Ltd | Health & social care | 2025 |
| Heart and Hands South Ltd | Other services | 2016 |
| Heart Health Diagnostics Ltd | Health & social care | 2025 |
| Heartfield Limited | Education | 2025 |
| Hearthlyre Ltd | Wholesale & retail | 2025 |
| Hearts on Care Recruitment Ltd | Health & social care | 2015 |
| Hearty Meals Delivered Ltd | Hospitality | 2024 |
| Heat Pump Acoustic Enclosures Limited | Construction | 2025 |
| Heat UP Property Services Ltd | Construction | 2013 |
| Heat Wave Hythe Ltd | Other services | 2021 |
| Heatcomp Limited | Construction | 2014 |
| Heath and Sinclair Limited | Other services | 1989 |
| Heathcroft Management Limited | Households | 1999 |
| Heather Consulting Ltd | Professional & scientific | 2023 |
| Heather Drive (Andover) Management Company Limited | Households | 1991 |
| Heather Paula Greenwood Ltd | Households | 2024 |
| Heather Property Limited | Construction | 2022 |
| Heathfield Products Limited | Wholesale & retail | 2012 |
| Heatworks Heating Limited | Construction | 2011 |
| Heavenly Botanticals Ltd | Wholesale & retail | 2025 |