| HAL Homes Limited | Real estate | 2021 |
| HAL Solutions Limited | Professional & scientific | 2013 |
| Hall Developments Bexley Limited | Construction | 2023 |
| Hamilton Contracting Limited | Construction | 2025 |
| Hamilton Place Limited | Information & communication | 1997 |
| Hamilton Place RES. Assoc. (Kingswood) Limited | Households | 1995 |
| Handy Candy Limited | Wholesale & retail | 2006 |
| Handy Hubby Hire Ltd | Construction | 2012 |
| Hannah Massey Limited | Health & social care | 2022 |
| Hapk Ltd | Information & communication | 2026 |
| Happy Buddies Ltd | Extraterritorial | 2024 |
| Harpurs Limited | Administrative & support | 2009 |
| Harris Windows and Joinery Limited | Manufacturing | 1999 |
| Hart & Co Properties Limited | Real estate | 2022 |
| Haswell Analytics Limited | Wholesale & retail | 2020 |
| Haweli of Tadworth Ltd | Hospitality | 2026 |
| Hawkins & Scott Ltd | Water & waste | 2011 |
| Hawkins Construction (London) Limited | Construction | 1967 |
| Haydan Properties Ltd | Real estate | 2018 |
| Hayfeguard Limited | Manufacturing | 2008 |
| HCL Fluid Power Limited | Manufacturing | 2001 |
| Healy Refrigeration & Air Conditioning Services Limited | Construction | 1985 |
| Healy's ACR Limited | Energy | 2014 |
| Heathside Accountancy Limited | Professional & scientific | 2021 |
| Heinecke Electrical Limited | Construction | 2014 |
| Helen Louise Limited | Other services | 2021 |
| Helen Miles Property Limited | Real estate | 2026 |
| Herons LEA Residents Management Company Limited | Households | 2013 |
| Hicklease Limited | Information & communication | 1998 |
| High Five Consultancy Ltd | Professional & scientific | 2021 |
| High Gear Limited | Professional & scientific | 2026 |
| High Standard Accommodation Ltd | Hospitality | 2026 |
| High Standard Group Ltd | Financial services | 2026 |
| High Standard Rope Access Ltd | Construction | 2018 |
| High Standard Safety Solutions Ltd | Manufacturing | 2026 |
| Highfield Chase (Freehold) Limited | Real estate | 2019 |
| Highland Charters Limited | Real estate | 1946 |
| Hillmond Limited | Hospitality | 2026 |
| Hillside Park Residents Company Limited | Households | 1967 |
| Hiretodrive Ltd | Administrative & support | 2026 |
| Holdan Electrical Ltd | Construction | 2011 |
| Holden Property Maintenance Limited | Construction | 2006 |
| Holly Lane Capital Limited | Professional & scientific | 2013 |
| Holt and Turner Ltd | Health & social care | 2019 |
| Holtstone Limited | Professional & scientific | 2014 |
| Home Hair With Vikki Ltd | Other services | 2023 |
| Home-Pigeon Ltd | Real estate | 2017 |
| Homescape Investments Ltd | Construction | 2020 |
| Hometec Limited | Real estate | 2003 |
| Honey & Bamboo Ltd | Wholesale & retail | 2019 |
| Hospira UK Limited | Manufacturing | 1985 |
| House and Home Management Ltd | Households | 2023 |
| Howard House Blue Limited | Construction | 2025 |
| Howard House LLP | | 2025 |
| Howells Properties Ltd | Real estate | 2019 |
| Howlett Holdings 878 Ltd | Financial services | 2025 |
| Hurley Birds Nursery Ltd | Health & social care | 2021 |
| HZ Soccer Solutions Limited | Education | 2016 |
| I AM NOT Just a Number Limited | Professional & scientific | 2023 |
| IB Easy Care Ltd | Health & social care | 2023 |
| Iconsult.Business Ltd | Professional & scientific | 2020 |
| Icthus Marine Limited | Wholesale & retail | 2016 |
| Ideal Forms Limited | Wholesale & retail | 2003 |
| Idominus Systems Ltd | Information & communication | 2017 |
| Idti Construction Limited | Transport & logistics | 2022 |
| Ifix Surrey Ltd | Manufacturing | 2026 |
| Immersive Worlds Ltd | Information & communication | 2024 |
| Imperial Tableware Ltd | Wholesale & retail | 2020 |
| Imperium Decorating Ltd | Construction | 2024 |
| Import Construction Limited | Construction | 2023 |
| IN2 Digital Print Limited | Manufacturing | 2014 |
| Indigo House Limited | Extraterritorial | 2014 |
| Indigo Office Design Limited | Wholesale & retail | 2005 |
| Indigo Worx Limited | Construction | 2023 |
| Inferbound Ltd | Wholesale & retail | 2025 |
| Infinitek Studios Limited | Information & communication | 2025 |
| Infinity Drains Ltd | Professional & scientific | 2025 |
| Innoscent Ltd | Manufacturing | 2018 |
| Integra Technical Limited | Professional & scientific | 1999 |
| Intelligent Mobility Limited | Wholesale & retail | 2018 |
| Interdev Marketing Limited | Professional & scientific | 2023 |
| International Risks and Control Advisory Ltd | Professional & scientific | 2015 |
| Intrulock Limited | Administrative & support | 2025 |
| Inventory Clerks 4U Ltd | Real estate | 2014 |
| Invinciblehuman Ltd | Health & social care | 2021 |
| IQ Dental Ltd | Health & social care | 2025 |
| Iqicharge Limited | Information & communication | 2014 |
| Iremco Limited | Financial services | 2021 |
| Isabelle Brooke Developments Ltd | Real estate | 2023 |
| J & G S Properties Limited | Real estate | 2000 |
| J & S L Design Ltd | Professional & scientific | 2020 |
| J a AA Perera Ltd | Professional & scientific | 2017 |
| J J Parshad Property Developers Ltd | Construction | 2025 |
| J Parfitt Consulting Ltd | Information & communication | 2024 |
| J Power Plumbing & Heating Ltd | Construction | 2014 |
| J&C Smart Consulting Limited | Professional & scientific | 2017 |
| Jack Gracey Ltd | Hospitality | 2024 |
| Jack N Plumbing Ltd | Construction | 2025 |
| Jackpotz Competitions Limited | Arts & recreation | 2023 |
| Jackson Computers Limited | Information & communication | 1985 |