| Hawthorn Theatrical Limited | Professional & scientific | 1981 |
| Hayco Estates Ltd | Real estate | 2025 |
| Hayes Cash & Carry Limited | Wholesale & retail | 2009 |
| Hayes FM Limited | Wholesale & retail | 2026 |
| Hayes Gate Plant Hire Limited | Construction | 1973 |
| Hayes Housing Ltd | Households | 2022 |
| Hayes Motors Ltd | Other services | 2008 |
| Hayes Recovery Heathrow Limited | Transport & logistics | 2025 |
| Hayes Sports Ltd | Arts & recreation | 2014 |
| Hayfields Cottages Limited | Real estate | 2025 |
| Haynes Skip Hire Limited | Water & waste | 2018 |
| Haynes Transport Services Ltd | Transport & logistics | 2025 |
| Hays Construction Limited | Construction | 2025 |
| HB Developments Limited | Real estate | 2017 |
| HB London Construction Ltd | Financial services | 2021 |
| HB Middlesex Ltd | Health & social care | 2025 |
| HBE Film & TV Holdings UK Limited | Professional & scientific | 2007 |
| Hbewasestates Ltd | Real estate | 2025 |
| Hbhuk Limited | Administrative & support | 2021 |
| HBL UK 1 Limited | Financial services | 2023 |
| HBL UK 2 Limited | Financial services | 2023 |
| HBL UK 3 Limited | Financial services | 2023 |
| HBL UK 4 Limited | Financial services | 2026 |
| HC Health Ltd | Health & social care | 2015 |
| HC123 Ltd | Construction | 2026 |
| Hcgc Investments Ltd | Real estate | 2018 |
| HCW Artist Management Ltd | Arts & recreation | 2026 |
| HD Holding Property Limited | Real estate | 2024 |
| HDA Logistics Limited | Transport & logistics | 2018 |
| HEAD2TOE Global Sourcing Ltd | Wholesale & retail | 2020 |
| Headbrook Homes Ltd | Construction | 2025 |
| Headcount Facilities Limited | Administrative & support | 2025 |
| Headcount FM Ltd | Administrative & support | 2013 |
| Healing Hands Hub C.I.C. | Health & social care | 2025 |
| Health Beyond Surgery Ltd | Health & social care | 2021 |
| Healthtech Infrareg Solutions Ltd | Construction | 2025 |
| Healthwatch Hillingdon | Public administration | 2013 |
| Healthy Cafes UK Limited | Hospitality | 2022 |
| Hear Holdings Limited | Real estate | 2020 |
| Heart Relocation Ltd | Transport & logistics | 2019 |
| Heatcore GAS Ltd | Construction | 2025 |
| Heath Builders Limited | Construction | 2019 |
| Heath Court UB10 Ltd | Households | 2021 |
| Heatherfields Estate Limited | Real estate | 2024 |
| Heathmead Developments Limited | Real estate | 2008 |
| Heathrow Carz Ltd | Wholesale & retail | 2016 |
| Heathrow Coaches Limited | Transport & logistics | 2019 |
| Heathrow Furniture Limited | Manufacturing | 2019 |
| Heathrow Parking Ltd | Administrative & support | 2013 |
| Heathrow Plant (Services) Ltd. | Administrative & support | 1990 |
| Heathrow Supplies Limited | Wholesale & retail | 2020 |
| Heathrow Truck Wash Ltd | Administrative & support | 2022 |
| Heathrow United Coaches Ltd | Transport & logistics | 2024 |
| Heathside Place Management Company Limited | Households | 1998 |
| Heatwave Construction Limited | Construction | 2016 |
| Heba Hakimzay Limited | Real estate | 2016 |
| Hecoanalytics Ltd | Professional & scientific | 2015 |
| Hedges Lighting Ltd | Professional & scientific | 2009 |
| Hedingham Mews Residents Association Limited | Real estate | 1991 |
| Hedomonia Ltd | Wholesale & retail | 2023 |
| Hefaure X Limited | Hospitality | 2021 |
| Hegadus Limited | Professional & scientific | 2014 |
| Heidelberg Graphic Equipment Limited | Manufacturing | 1974 |
| Heidelberg Group Trustees Limited | Professional & scientific | 1982 |
| Hela BPC Ltd | Health & social care | 2026 |
| Helen Nicholson Limited | Professional & scientific | 2015 |
| Helix Software Ltd. | Information & communication | 2022 |
| Hello Signage Ltd | Manufacturing | 2022 |
| Hello Sunshine Tanning Limited | Other services | 2020 |
| Hello World Academy Ltd | Information & communication | 2024 |
| Helloberry Tech Innovation Distributions Ltd | Wholesale & retail | 2018 |
| Hemi Heating Ltd | Construction | 2014 |
| Hemmingway Shwartz Ltd | Wholesale & retail | 2019 |
| Hendon Way Court Limited | Construction | 2024 |
| Henley 44 Limited | Real estate | 2021 |
| Henley Healthcare Group Limited | Health & social care | 2022 |
| Henry Hutchin Limited | Information & communication | 2015 |
| Henrys Enterprise Limited | Professional & scientific | 2008 |
| Heramba Tech UK Ltd | Information & communication | 2018 |
| Herbalife (U.K.) Limited | Wholesale & retail | 1983 |
| Herbalife Europe Limited | Other services | 1996 |
| Hereson House Limited | Health & social care | 2002 |
| Herford Limited | Real estate | 2022 |
| Heritage Property Leasing and Management Ltd | Real estate | 2021 |
| Heritage Windows & Kitchens Ltd | Other services | 2010 |
| Hermitage AI Ltd | Agriculture & fishing | 1998 |
| Heronslee (Flats) Residents Association Limited | Households | 2010 |
| Heronslee Residents Association Limited | Households | 2010 |
| Herts Care (Escort and Supervision Services) Ltd. | Health & social care | 1998 |
| Herts Care Group Ltd. | Financial services | 2002 |
| Herts Care Limited | Extraterritorial | 1997 |
| Herts Care Property Ltd. | Extraterritorial | 2000 |
| Hertz Accident Support Ltd | Administrative & support | 2009 |
| Hertz Holdings III UK Limited | Administrative & support | 2005 |
| Hertz UK Receivables Ltd | Financial services | 2013 |
| Hertz Vehicle Financing U.K. Limited | Financial services | 2013 |
| Heston Mini Skips Limited | Water & waste | 2018 |
| HEY DEE HO Music UK Ltd | Education | 2023 |
| HG Theobald Scenic Ltd | Construction | 2025 |
| Hgsg Investments Ltd | Real estate | 2022 |