| Hatched Art (UK) Limited | Manufacturing | 2017 |
| Hathaway Accounting Solutions Ltd | Professional & scientific | 2024 |
| Hathi Healthcare Ltd | Health & social care | 2017 |
| Hatmadah Limited | Administrative & support | 2019 |
| Haus to Home Limited | Real estate | 2023 |
| Have and Share Ltd | Information & communication | 2020 |
| Havenly Properties Limited | Real estate | 2018 |
| Hawksnest Limited | Professional & scientific | 2013 |
| Hay-Vive Ltd | Manufacturing | 2025 |
| Hayati Medical Solutions Limited | Health & social care | 2025 |
| Haycrest Properties Limited | Real estate | 2017 |
| Hayesthorne Limited | Construction | 1992 |
| Hbpl Limited | Construction | 2025 |
| Head Legal Consultancy Limited | Professional & scientific | 2013 |
| Headhunter Systems Limited | Other services | 2009 |
| Headstone Property Management Ltd | Other services | 2018 |
| Healthcare Medical Services Ltd | Health & social care | 2016 |
| Healthy Minds 11 Plus Limited | Education | 2025 |
| Heart of the Jester Limited | Professional & scientific | 2004 |
| Heart Rituals Ltd | Wholesale & retail | 2023 |
| Heartbeat Media Ltd | Information & communication | 2024 |
| Hearthside Properties Ltd | Real estate | 2023 |
| Heath END Management Limited | Households | 2014 |
| Heath Kemp Limited | Construction | 2016 |
| Heath Wilson Consulting Limited | Professional & scientific | 2024 |
| Heathdene Manor RTM Company Ltd | Households | 2019 |
| Heather Inc Limited | Real estate | 2024 |
| Heathfield 1 Ltd | Real estate | 2023 |
| Heathgate Block Management Ltd | Households | 2021 |
| Heavenly Spaces Limited | Professional & scientific | 2005 |
| Hedian Partners Ltd | Wholesale & retail | 2018 |
| Heelis Event Consulting Limited | Professional & scientific | 2008 |
| Heeyas Ltd | Wholesale & retail | 2007 |
| Hegeston Estates Limited | Real estate | 1937 |
| Helion Place Ltd | Real estate | 2008 |
| Hello Harley Limited | Wholesale & retail | 2024 |
| Help Housing Ltd | Real estate | 2024 |
| Help Recruitment Ltd | Administrative & support | 2020 |
| Helping Authors Achieve Results Ltd | Professional & scientific | 2024 |
| Hemel Hempstead Property Co. (Apsley) Limited | Construction | 1966 |
| Henc Services Ltd | Professional & scientific | 2024 |
| Hendy Consulting Limited | Professional & scientific | 2006 |
| Henry Mansfield Limited | Construction | 1945 |
| Herdyworks Ltd | Professional & scientific | 2026 |
| Here and NOW KID Ltd | Other services | 2022 |
| Hereford Mansions Limited | Other services | 2003 |
| Heriots Capital NO. 2 LLP | | 2010 |
| Heriots Residential Limited | Real estate | 2010 |
| Heriots Residential NO2 LLP | | 2010 |
| Heritage Care Recruitment Ltd | Health & social care | 2022 |
| Heritage Technology Ltd | Construction | 2023 |
| Herlo Capital Limited | Financial services | 2013 |
| Herocouriers Ltd | Transport & logistics | 2026 |
| Hertfordshire Maintenance Services Limited | Professional & scientific | 2021 |
| Herts Plant Supply Limited | Professional & scientific | 2014 |
| Hester Van Royen Limited | Wholesale & retail | 2015 |
| Hewad Welfare | Education | 2014 |
| HEX Mechanical Services Ltd | Construction | 2025 |
| Hexate Ltd | Information & communication | 2002 |
| Hexera Limited | Professional & scientific | 2026 |
| Heywood Management Limited | Households | 1980 |
| Hezuo Ltd | Real estate | 2026 |
| HG Watches Ltd | Administrative & support | 2015 |
| HGL Travel Limited | Extraterritorial | 2019 |
| HGW Enterprise Ltd | Real estate | 2020 |
| HH Urology Limited | Health & social care | 2019 |
| HHM Health Ltd | Health & social care | 2025 |
| HI Profile Consulting Ltd | Professional & scientific | 2024 |
| HI Property Management Services Limited | Real estate | 2024 |
| Hi-Tech Hardware Limited | Wholesale & retail | 2020 |
| Hidden Agenda Limited | Information & communication | 1996 |
| Hidehouse (UK) Ltd | Manufacturing | 2009 |
| High Seas Sailing Club Limited | Other services | 2009 |
| High Springers LLP | | 2017 |
| High YS Ltd | Real estate | 2023 |
| Highdown Investments Limited | Real estate | 2020 |
| Hilden & Co Estates Limited | Real estate | 2025 |
| Hilden Management Limited | Professional & scientific | 2023 |
| Hill House (RTM) Company Limited | Households | 2024 |
| Hillcrest Court (Edgware) Limited | Households | 1982 |
| Hillfield Property Services Limited | Real estate | 2018 |
| Hillhouse Capital Ltd | Other services | 2024 |
| Himani's Home Limited | Real estate | 2023 |
| Hintcrest Limited | Arts & recreation | 1983 |
| Hintgate Limited | Arts & recreation | 1983 |
| Hippo Real Estates Limited | Real estate | 2023 |
| Hipster Films Ltd | Information & communication | 2017 |
| Hira 81 Enterprise Ltd | Wholesale & retail | 2024 |
| Hirani Building Solutions Limited | Construction | 2011 |
| Hirani Engineers Limited | Professional & scientific | 2016 |
| Hixy Kraft Creations Ltd | Wholesale & retail | 2023 |
| HJB26 Limited | Real estate | 2026 |
| HK Bright Builders Ltd | Construction | 2025 |
| HK Jesani Limited | Construction | 2017 |
| HK2 Properties Ltd | Real estate | 2026 |
| Hkmp Limited | Real estate | 2017 |
| Hlact UK Ltd | Professional & scientific | 2025 |
| HLR Property Sales Limited | Administrative & support | 2005 |
| HLV Consulting Limited | Financial services | 2007 |
| HN Pack & Storage Ltd | Wholesale & retail | 2014 |