| Hanlor Court Management Company Limited | Households | 1988 |
| Hanson Estimating Solutions Ltd | Professional & scientific | 2019 |
| Happy Sandpit Limited | Education | 2023 |
| Harcourt (Bushey) Amenities Association Limited | Households | 1962 |
| Hardingstone Court (Waltham Cross) Management Company Limited | Other services | 1988 |
| Hardwick Heights Management Company Limited | Households | 2007 |
| Hare and Ransome Joinery Ltd | Construction | 2014 |
| Harknett Street Lighting Limited | Administrative & support | 2008 |
| Harley Mullion & Co. Ltd. | Transport & logistics | 1992 |
| Harling Security Solutions Limited | Construction | 2017 |
| Harlow Luxury Hand Car Wash Ltd | Wholesale & retail | 2026 |
| Harmonia Court Management Company Limited | Households | 2010 |
| Harmony Build Ltd | Construction | 2019 |
| Harper House (Chafford Hundred) Management Company Limited | Households | 2003 |
| Harpreet Kaur Ltd | Information & communication | 2009 |
| Harriet Muncaster Limited | Arts & recreation | 2019 |
| Harrows Game Shot Limited | Manufacturing | 1994 |
| Hart Contractors Ltd | Administrative & support | 2002 |
| Harvey & Co. Investments Ltd | Real estate | 2025 |
| Harvey Potts Limited | Construction | 2020 |
| Hasuman Medic Ltd | Health & social care | 2021 |
| HAT to Socks Ltd | Wholesale & retail | 2016 |
| Hatherley Care Home Limited | Health & social care | 2002 |
| HAV Building Services Limited | Real estate | 2023 |
| Haven Gardens (Darlington) Residents Association Limited | Households | 2003 |
| Hawthorn (Battle) Residents Management Company Limited | Households | 2021 |
| Hawthornden Yalding Management Company Limited | Households | 2018 |
| Hawthorne Croft Management Company Limited | Households | 2011 |
| Hawthornes Management (South) Limited | Households | 1987 |
| Hawthorns (West Drayton) NO. 2 Residents Company Limited | Households | 1988 |
| Hawthorns (West Drayton) NO.1 Residents Company Limited | Households | 1987 |
| Haywood EV Ltd | Construction | 2019 |
| HB Accountants Limited | Professional & scientific | 2012 |
| HB Wealth Management LLP | | 2010 |
| Hbas Limited | Professional & scientific | 2004 |
| HBR Consulting Limited | Information & communication | 2021 |
| HBT Fashions Ltd | Wholesale & retail | 2019 |
| HCL (Churchgate) Limited | Extraterritorial | 2016 |
| HCL (Hertford Road) Limited | Extraterritorial | 2016 |
| HCL (Nun's Triangle) Limited | Construction | 2016 |
| Hctip Limited | Professional & scientific | 2024 |
| Heartenoak Meadows Hawkhurst Management Company Limited | Households | 2020 |
| Hearts to Love Limited | Manufacturing | 2024 |
| Heartwood Specialist Joinery & Restoration Ltd | Construction | 2020 |
| Heath Landscapes Ltd | Administrative & support | 2017 |
| Heathcote Raymond Limited | Professional & scientific | 2006 |
| Heatherdown Management Company Limited | Households | 2010 |
| Heatherley Wood Residents Management Company Limited | Households | 2019 |
| Heathlands (Colchester) Management Company Limited | Households | 2006 |
| Heathlea Gardens Management Limited | Households | 2013 |
| Heatsoft Limited | Construction | 2003 |
| Hebson Horseboxes Ltd | Manufacturing | 2017 |
| Hedingham Gate (Chafford Hundred) Management Company Limited | Households | 2001 |
| Helix Property & Estates Management Ltd | Real estate | 2009 |
| Hello Hosty Limited | Information & communication | 2023 |
| Helmbrook Ltd | Wholesale & retail | 2020 |
| Hemingway Court Management Company Limited | Real estate | 2018 |
| Henderson Architectural Hardware Limited | Manufacturing | 2007 |
| Henderson Hardware Limited | Wholesale & retail | 2002 |
| Hendon Tyre Service Limited | Wholesale & retail | 1965 |
| Hendon Tyres Limited | Wholesale & retail | 2002 |
| Hendon Tyres Properties Limited | Real estate | 2005 |
| Henmore Gardens Management Company Limited | Households | 2018 |
| Heritage Green (Culcheth) Management Company Limited | Households | 2014 |
| Heritage House (York) Limited | Real estate | 2016 |
| Heritage Park Management Company Phase IV Limited | Households | 2007 |
| Heritage Sash Windows London Limited | Construction | 2024 |
| Herne Lodge (Oundle) Management Company Limited | Households | 2015 |
| Herons Reach Home Owners Services Limited | Households | 2008 |
| Hertford Company Secretaries Limited | Professional & scientific | 1995 |
| Hertford Investment Properties Limited | Construction | 2002 |
| Hertford London Ltd | Hospitality | 2020 |
| Hertford Specialist Builders Ltd | Construction | 2025 |
| Hertfordshire Building Company Limited | Construction | 2009 |
| Hertfordshire Metal Finishing Limited | Manufacturing | 2022 |
| Hertingfordbury Management Company Ltd. | Households | 1997 |
| Hertingfordbury Road Management Limited | Households | 2020 |
| Herts & City Plumbing & Maintenance Ltd | Construction | 2021 |
| Herts & Essex Carriage Masters Ltd | Other services | 2012 |
| Herts & Essex Garage Doors Ltd | Construction | 2020 |
| Herts Airport Transfers Ltd | Transport & logistics | 2026 |
| Herts and Essex Motor Company Ltd | Wholesale & retail | 2015 |
| Herts Granite Ltd Ltd | Manufacturing | 2025 |
| Herts Motors Limited | Wholesale & retail | 2010 |
| Herts Roofing Contractors Ltd | Construction | 2020 |
| Herts Weddings Ltd | Professional & scientific | 2026 |
| Hethersett Residents Management Company Limited | Households | 2016 |
| Heward & Dean (BD) Limited | Wholesale & retail | 2001 |
| Hexalogic Group Ltd | Information & communication | 2025 |
| HEY Mamma Limited | Hospitality | 2022 |
| HH Muckers Limited | Transport & logistics | 2015 |
| HH Paradise Limited | Real estate | 2021 |
| HH South East Limited | Real estate | 2018 |
| HHH Academy Ltd | Arts & recreation | 2024 |
| Hidden Hair Solutions Limited | Education | 2026 |
| Hidden Vapes Limited | Wholesale & retail | 2018 |
| High Beeches (Sharston) Management Company Limited | Households | 2004 |
| High Beeches Management Company (Clitheroe) Limited | Households | 2018 |
| High Design LDN Ltd | Manufacturing | 2019 |
| High Oak House Management Company Limited | Households | 2015 |