| Harshtech Ltd | Information & communication | 2026 |
| Hartfield Road Limited | Extraterritorial | 2014 |
| Hartland Residential Home Ltd | Hospitality | 1996 |
| Haru Group Ltd | Hospitality | 2026 |
| Haru Partners Ltd | Hospitality | 2022 |
| Hastings P3M Consulting Ltd | Professional & scientific | 2018 |
| Hastings P3M Ltd | Information & communication | 2017 |
| Haydons Road Wimbledon Property Company Limited | Real estate | 1929 |
| Hayflo&Co. Limited | Professional & scientific | 2024 |
| Hb&S Estates Limited | Real estate | 2023 |
| HBC Renovation Ltd | Construction | 2024 |
| Hcventureco Ltd | Professional & scientific | 2024 |
| HDL Investment Ltd | Financial services | 1990 |
| Head Over Feels Ltd | Other services | 2025 |
| Heal NEX Ltd | Wholesale & retail | 2024 |
| Healthisgrowth Ltd | Manufacturing | 2025 |
| Healthtech Delops Ltd | Professional & scientific | 2024 |
| Healvip Ltd | Administrative & support | 2018 |
| Heath Court (Carshalton) Limited | Real estate | 1985 |
| Heaven Garden Care Ltd | Administrative & support | 2023 |
| Hehan International Holding Group Ltd | Financial services | 2014 |
| Helios Contractors Ltd | Construction | 2018 |
| Hello Neighbour Limited | Information & communication | 2017 |
| Helpdart Limited | Real estate | 1986 |
| HEN Supply Ltd | Wholesale & retail | 2025 |
| Hengewood Ltd | Professional & scientific | 2012 |
| Hentrics & Co Ltd | Professional & scientific | 2019 |
| Herbal Wellness International Ltd | Manufacturing | 2020 |
| Hertford Lodge Limited | Households | 1997 |
| Hexas Ltd | Wholesale & retail | 2021 |
| HEY Boiler Ltd | Construction | 2025 |
| HF Futures Ltd | Financial services | 2026 |
| HHN Consultancy Ltd | Administrative & support | 2024 |
| High Drive Property Management Ltd | Real estate | 2022 |
| Himalaya SLJ Limited | Construction | 2022 |
| Himtel Connect Ltd | Wholesale & retail | 2026 |
| Hind House Management Limited | Households | 1983 |
| Hitech EMS Ltd | Construction | 2010 |
| Hizen Limited | Professional & scientific | 2018 |
| Hjel Studio Ltd | Wholesale & retail | 2021 |
| HK Home Sweet Home UK Ltd | Manufacturing | 2021 |
| Hkmi Ltd | Wholesale & retail | 2024 |
| HMO Consultants Ltd | Professional & scientific | 2023 |
| HN7 Building Solutions Ltd | Construction | 2022 |
| Hoklly Limited | Professional & scientific | 2024 |
| Holborn Business Management Ltd | Professional & scientific | 2026 |
| Hollwood Limited | Real estate | 2024 |
| Hollytree Close Limited | Professional & scientific | 1995 |
| Home Comms Limited | Professional & scientific | 2019 |
| Home Friendly Hunter Ltd | Hospitality | 2023 |
| Home Friendly Maintenance Ltd | Households | 2021 |
| Homeeffect Ltd | Wholesale & retail | 2020 |
| Homefield Management Limited | Households | 1995 |
| Homefy Property Limited | Real estate | 2021 |
| Honey's Doggy Daycare Ltd | Professional & scientific | 2014 |
| Honeybee London Ltd | Wholesale & retail | 2016 |
| HONEYCOMB999 Limited | Wholesale & retail | 2016 |
| Hongjian Zhuangxiu Limited | Construction | 2023 |
| Hooklands Limited | Health & social care | 2015 |
| Hooks Property Management Ltd | Real estate | 2018 |
| HOP & Vine ELM Ltd | Wholesale & retail | 2023 |
| Hoppers Spot Ltd | Hospitality | 2025 |
| Horangi Ltd | Wholesale & retail | 2023 |
| Hot Loft Ltd | Construction | 2020 |
| Hotel Atour Ltd | Hospitality | 2024 |
| Hotgrips UK Ltd | Professional & scientific | 2021 |
| House Experts Ltd | Real estate | 2021 |
| Howsit Ltd | Wholesale & retail | 2017 |
| Hristan Ltd | Construction | 2025 |
| HRS Connect Apps Ltd | Information & communication | 2024 |
| HS Safa Limited | Administrative & support | 2025 |
| HSQ Consultants Limited | Professional & scientific | 2023 |
| Ht&T Civil Contractors Ltd | Construction | 2012 |
| Hughes Engineering Consultancy Services Limited | Professional & scientific | 2001 |
| HUI Music Ltd | Education | 2021 |
| Human Made Property Services Ltd | Construction | 2026 |
| Humax Direct Ltd | Manufacturing | 2007 |
| Hyeon Ltd | Health & social care | 2012 |
| Hyosung UK Limited | Manufacturing | 2025 |
| HYPERACTIV8 Ltd | Information & communication | 2024 |
| Hypnosis LLP | | 2013 |
| Hyundai Investment Trust & Securities Co., Ltd. | | 1995 |
| I a R Property Ltd | Real estate | 2024 |
| I Love London Ltd | Transport & logistics | 2024 |
| I&T Services Limited | Information & communication | 2017 |
| I. E. S Building Services Ltd | Construction | 2017 |
| I2 Identity Consulting Limited | Information & communication | 2016 |
| IBI Entertainment Limited | Other services | 2009 |
| IH Aesthetics Sanctuary Ltd | Other services | 2024 |
| Iktifa Ltd | Health & social care | 2012 |
| IL Villaggio Deli & Bar Limited | Wholesale & retail | 2024 |
| Iliad Asset Holdings Limited | Real estate | 2021 |
| Ilikeedam Limited | Professional & scientific | 2012 |
| Illegal Racing Limited | Manufacturing | 2018 |
| Image Africa Ltd | Wholesale & retail | 2019 |
| Immanuel B&S Ltd | Wholesale & retail | 2020 |
| Imone BBQ Ltd | Hospitality | 2024 |
| Imone Korean Restaurant Ltd | Hospitality | 2018 |
| Impress Care Service Ltd | Administrative & support | 2025 |
| Impromptu Social Limited | Information & communication | 2018 |