| Habitability Limited | Professional & scientific | 2019 |
| Habits for Health Ltd | Extraterritorial | 2024 |
| Habod Care Ltd | Health & social care | 2011 |
| Haffenden Fine Art and Antiques Ltd | Wholesale & retail | 2024 |
| Haffenden Skip Hire Limited | Extraterritorial | 2020 |
| Hagar’S House Ltd | Hospitality | 2026 |
| Hagley Spice Ltd | Hospitality | 2023 |
| Hair and Skin Medical UK Limited | Health & social care | 2023 |
| Hair Court Ltd | Other services | 2023 |
| Hair of the Dog Kent Ltd | Other services | 2021 |
| Hair Professional Limited | Other services | 1979 |
| Hairbybekrin Ltd | Wholesale & retail | 2025 |
| Hairose Limited | Other services | 2020 |
| Hairpark Limited | Other services | 2020 |
| Hairtamin Limited | Extraterritorial | 2022 |
| Hajis Fast Food Ltd | Hospitality | 2023 |
| Hakeman Property Group Ltd | Real estate | 2025 |
| HAL Media Ltd | Wholesale & retail | 2021 |
| Hale Place Manor Ltd | Health & social care | 2025 |
| Haley & Co Consulting Ltd | Information & communication | 2025 |
| Halide Limited | Information & communication | 2018 |
| Halkin Services Limited | Information & communication | 2002 |
| Hall Distribution Ltd | Wholesale & retail | 2023 |
| Hall Refrigeration Wholesale Limited | Manufacturing | 1989 |
| Hallmark Signs Limited | Manufacturing | 2001 |
| Hallsdale Insurance Brokers Limited | Financial services | 2007 |
| Hallskon Ltd | Wholesale & retail | 2023 |
| Halshaw Architecture Ltd | Professional & scientific | 2018 |
| Halstead Incubation Partners Ltd | Information & communication | 2023 |
| HAM Lane Management (1993) Limited | Real estate | 1993 |
| Hamco Investments Ltd | Construction | 2021 |
| Hamilton & Palmer Installations Ltd. | Manufacturing | 1998 |
| Hamilton Coopers Accountants Limited | Professional & scientific | 2006 |
| Hamilton Coopers Investment Limited | Financial services | 2013 |
| Hamilton Coopers Limited | Extraterritorial | 2009 |
| Hamilton Homes & Developments Ltd | Construction | 2021 |
| Hamilton Kitchens Limited | Construction | 2010 |
| Hamjo Consulting Limited | Information & communication | 2017 |
| Hamk Holdings Limited | Financial services | 2026 |
| Hammond Land and Consulting Limited | Construction | 2023 |
| Hampson Roofing Limited | Construction | 2018 |
| Hamynat Ltd | Wholesale & retail | 2023 |
| HANA03 Ltd | Real estate | 2024 |
| Hanatas Limited | Financial services | 2020 |
| Hanbury Farms Limited | Wholesale & retail | 2015 |
| Handf Finance Limited | Financial services | 1980 |
| Hands London Consultancy Ltd | Professional & scientific | 2021 |
| Handymend.Com Ltd | Construction | 2012 |
| Hanuti Limited | Information & communication | 2024 |
| Haodha Ltd | Construction | 2022 |
| Haowei Limited | Hospitality | 2019 |
| Happinest Properties Ltd | Real estate | 2021 |
| Happy Days Property Management Limited | Real estate | 2017 |
| Happy Hygiene Ltd | Health & social care | 2022 |
| Happy Junk Ltd | Water & waste | 2024 |
| Happy Panda 360 Limited | Hospitality | 2024 |
| Happy Tales Pet Care Ltd | Other services | 2021 |
| Happymomo Ltd | Hospitality | 2023 |
| Harbour Farm Limited | Other services | 2019 |
| Harco Construction Ltd | Construction | 2024 |
| Hardy Exploration & Production (India) Inc. | | 1999 |
| Hardy Team Ltd | Wholesale & retail | 2018 |
| Harijee Ltd | Wholesale & retail | 2026 |
| Harka Limited | Professional & scientific | 2008 |
| Harlend Computer Services Limited | Information & communication | 1998 |
| Harlequin Building Contractors Limited | Construction | 2013 |
| Harlequin Fitted Furniture Limited | Manufacturing | 2003 |
| Harling Bespoke Limited | Manufacturing | 2023 |
| Harman Aviation Ltd | Transport & logistics | 2017 |
| Harmer Court Limited | Real estate | 1999 |
| Harmonic Labs Limited | Information & communication | 2025 |
| Harmony Wellness and Aesthetics Ltd | Other services | 2025 |
| Harpers & Hurlingham Limited | Real estate | 2010 |
| Harpswood Residents Management Company Limited | Households | 2019 |
| Harpurhey Contractors Limited | Professional & scientific | 2022 |
| Harrietsham Garage & MOT Limited | Wholesale & retail | 2024 |
| Harringtons Design Services Limited | Professional & scientific | 2013 |
| Harringtons Kent Limited | Real estate | 2024 |
| Harris Industrial Engineering Ltd | Professional & scientific | 2019 |
| Harrisons Property Investment Limited | Construction | 2026 |
| Harrisons Property Services Limited | Professional & scientific | 2026 |
| Harrisons Property Surveyors Limited | Professional & scientific | 1988 |
| Harrow Network Partners Ltd | Health & social care | 2024 |
| Harryken Healthcare UK Ltd | Health & social care | 2016 |
| Hart Time Ltd | Wholesale & retail | 2024 |
| Hart's Construction Ltd | Construction | 2024 |
| Hartnell Brede Motors Limited | Wholesale & retail | 1980 |
| Hartridge Developments Limited | Construction | 2015 |
| Haruspex Insights Ltd | Information & communication | 2025 |
| Harvey Communications Ltd | Professional & scientific | 2024 |
| Harvey Maintenance Ltd | Construction | 2026 |
| Hassle Free Logistics Service Ltd | Transport & logistics | 2020 |
| Hastings HOMECARE24 Ltd | Health & social care | 2025 |
| Hatch Contractors Limited | Construction | 2026 |
| Hatchett and Co Ltd | Manufacturing | 2013 |
| Haute Limited | Information & communication | 2005 |
| Havannah Properties Ltd | Real estate | 2017 |
| Havas Canada Holdings Limited | Professional & scientific | 2006 |
| Havas Consumer Health Limited | Professional & scientific | 1995 |
| Havas CX Limited | Professional & scientific | 2005 |