| H2H Esports Limited | Arts & recreation | 2020 |
| H2O International UK Ltd | Wholesale & retail | 2008 |
| H2OHM Ltd | Construction | 2024 |
| H3P Technologies Limited | Wholesale & retail | 1998 |
| H4F Ltd | Real estate | 2018 |
| H4HOMES Limited | Construction | 1999 |
| H5 Plastering Ltd | Construction | 2021 |
| HA Photography Limited | Professional & scientific | 2023 |
| HAA Wealth Management Limited | Financial services | 2012 |
| Haam Properties Ltd | Real estate | 2021 |
| Haara Ltd | Wholesale & retail | 2018 |
| Habibi's Property Limited | Real estate | 2018 |
| Habitdom Ltd | Professional & scientific | 2016 |
| Habivest Ltd | Real estate | 2018 |
| Hably HQ Limited | Information & communication | 2021 |
| Hackett and Morgan Group Ltd | Professional & scientific | 2016 |
| Haddenham Garden Centre Limited | Wholesale & retail | 1977 |
| Haddoum Training Ltd | Professional & scientific | 2006 |
| Haden Ductwork Ltd | Construction | 2012 |
| Hades Trans Ltd | Construction | 2021 |
| Hadron Investment Ltd | Real estate | 2023 |
| Haig Lettings Limited | Real estate | 2021 |
| Haig Property Professionals Ltd | Real estate | 2021 |
| Haik's House Ltd | Transport & logistics | 2021 |
| Hailly Private Limited | Administrative & support | 2014 |
| Hair & Beauty Fusion Ltd | Other services | 2020 |
| Hair & Skin Care Ltd | Wholesale & retail | 2018 |
| Hair by Eden Limited | Wholesale & retail | 2011 |
| Hair by EVA Ltd | Other services | 2026 |
| Hair DR Academy Ltd | Other services | 2025 |
| Hair DR Ltd | Other services | 2024 |
| Hair Masters Stony Stratford Limited | Other services | 2004 |
| Haircraft Inc Ltd | Other services | 2021 |
| Hairizon Limited | Other services | 2010 |
| Hairjessers Ltd | Other services | 2017 |
| Haixing Network Ltd | Wholesale & retail | 2025 |
| Haize Limited | Health & social care | 2024 |
| Hajgo Ltd | Transport & logistics | 2022 |
| Haji TM Ltd | Construction | 2024 |
| HAK Living Ltd | Financial services | 2023 |
| Hakim Ghani Ltd | Real estate | 2022 |
| Hakimco UK Ltd | Real estate | 2025 |
| Haks Consultancy Ltd | Professional & scientific | 2024 |
| HAL Group London Ltd | Hospitality | 2023 |
| Halami Ltd | Manufacturing | 2026 |
| Halasz Estates Ltd | Real estate | 2025 |
| Hale Home Care Ltd | Health & social care | 2025 |
| Haledawn Limited | Information & communication | 2003 |
| Half Moon Consulting Limited | Information & communication | 2023 |
| Hall Green Business Solutions Ltd | Administrative & support | 2016 |
| Hall Walsham Development Limited | Construction | 2025 |
| Hallmark Consulting Limited | Professional & scientific | 2016 |
| Halnique Ltd | Wholesale & retail | 2022 |
| Halo Coffee Limited | Manufacturing | 2016 |
| Halo Digital Limited | Wholesale & retail | 2016 |
| Halo Research Technology Ltd | Public administration | 2022 |
| Halofeast Ltd | Wholesale & retail | 2025 |
| Halomint Retail Ltd | Wholesale & retail | 2026 |
| Halona Holistics Limited | Administrative & support | 2020 |
| Halwaa Ltd | Hospitality | 2022 |
| Hamad Acquisition Ltd | Information & communication | 2026 |
| Hamara Chaska Ltd | Wholesale & retail | 2025 |
| Hamd Limited | Real estate | 2023 |
| Hamdoud Property Investment Ltd | Real estate | 2025 |
| Hamedan Holdings Ltd | Financial services | 2025 |
| Hami Advisory Ltd | Professional & scientific | 2025 |
| Hamilton & Co Properties Limited | Real estate | 2019 |
| Hamilton & Rowe Limited | Professional & scientific | 2024 |
| Hamilton and Associates Ltd | Wholesale & retail | 2014 |
| Hamilton Automation Ltd | Information & communication | 2023 |
| Hamilton Brooks Limited | Administrative & support | 2012 |
| Hamilton Court (Buckingham) Management Limited | Households | 1990 |
| Hamilton Distribution Ltd | Wholesale & retail | 2023 |
| Hamilton Meeks Limited | Real estate | 2015 |
| Hamilton Properties Group Limited | Real estate | 2019 |
| Hammett Equestrian Limited | Wholesale & retail | 2010 |
| Hammond & Dummer Ltd | Wholesale & retail | 2006 |
| Hammond Rock Limited | Financial services | 2024 |
| Hammond Rutts Investments Limited | Real estate | 2013 |
| Hamoki Limited | Wholesale & retail | 2018 |
| Hamoki Property Limited | Construction | 2026 |
| Hampden Fairfax Limited | Real estate | 2018 |
| Hampers Bazaar Ltd | Wholesale & retail | 2024 |
| Hampshire Roofing Limited | Construction | 2011 |
| Hampstead Window Restoration Company Limited | Construction | 2023 |
| Hampstead Window Restorers Limited | Construction | 2023 |
| Hampton Park Management Company Limited | Households | 2000 |
| Hamptons Charter & Rental Limited | Real estate | 1997 |
| Hamptons Pools and Property Maintenance Ltd | Construction | 2026 |
| Hanaa Iftikhar Healthcare Ltd | Health & social care | 2025 |
| Hanaina Properties Limited | Construction | 2025 |
| Hanco Cybertech Ltd | Information & communication | 2019 |
| Hanco Global Solutions Ltd | Information & communication | 2015 |
| Hand Picked Mortgages Ltd | Financial services | 2005 |
| Handled Socials Ltd | Professional & scientific | 2026 |
| HANDLER24 Ltd | Information & communication | 2025 |
| Handmade and British Limited | Manufacturing | 2019 |
| Handmade by Betty Ltd | Manufacturing | 2024 |
| Handmade Records Ltd | Arts & recreation | 2019 |
| Hands Community Division C.I.C. | Education | 2025 |