| Headway Solutions Ltd | Professional & scientific | 2025 |
| Health & Beauty Investments Limited | Real estate | 2006 |
| Health Food Monkey Ltd | Wholesale & retail | 2018 |
| Health Psychology Research Limited | Professional & scientific | 2003 |
| Hearthstone Accountants Limited | Professional & scientific | 2021 |
| Hearthstone Advisory Limited | Financial services | 2017 |
| Hearthstone Estate Planning Limited | Professional & scientific | 2021 |
| Heatmatters Limited | Construction | 2015 |
| Heavenly Havens Limited | Administrative & support | 2022 |
| Hebron Holding Group Ltd | Health & social care | 2025 |
| Hedgerley Fields Limited | Real estate | 2008 |
| Hedgerley Lane Management Company Limited | Real estate | 2001 |
| Heffernan Talent Partners Ltd | Administrative & support | 2021 |
| Helen Bligh Consulting Limited | Professional & scientific | 2018 |
| Helene Patounas Nutrition Ltd | Health & social care | 2013 |
| Hemel 6B Limited | Real estate | 2020 |
| Hemel Property Investments Ltd | Real estate | 2018 |
| Henry Bridburg and Co Ltd | Extraterritorial | 2012 |
| Henry DE Bracton Psychology Chambers Ltd | Health & social care | 2018 |
| Herbal Research Company Limited(The) | Health & social care | 1963 |
| Herbal Research International Ltd | Extraterritorial | 2014 |
| Herd in Motion Limited | Information & communication | 2025 |
| Herialkin Ventures Ltd | Real estate | 2026 |
| Heritage Hotel Operations Ltd | Hospitality | 2024 |
| Heritage Properties Services Limited | Real estate | 2021 |
| Hetzel Limited | Professional & scientific | 2018 |
| Hewett Dotty & Co Consulting Ltd | Administrative & support | 2014 |
| Hfhcorporation Limited | Professional & scientific | 2023 |
| Hidden Pins Limited | Administrative & support | 2025 |
| High Meadows Farm Management Limited | Financial services | 2025 |
| High Tide Twickenham CIC | Arts & recreation | 2023 |
| Highend Investments Limited | Construction | 2022 |
| Highlife Marketing Limited | Administrative & support | 2002 |
| Highveld Ascot Ltd | Real estate | 2026 |
| Highviews Accounts Limited | Professional & scientific | 2023 |
| Highway 1 Investments Ltd | Financial services | 2021 |
| Hilkiah Services Ltd | Information & communication | 2019 |
| Hillingdon Communications Ltd | Information & communication | 1999 |
| Hillingford Limited | Real estate | 2021 |
| Hilversum Enterprises Limited | Professional & scientific | 2021 |
| Hipp Hipp Inns Limited | Financial services | 2021 |
| Hipwell Associates Limited | Professional & scientific | 2024 |
| Hirewheels Ltd | Information & communication | 2026 |
| Hither Meadow Management Company Ltd | Households | 1997 |
| HM Consulting Group Limited | Professional & scientific | 2017 |
| HMP Holding Limited | Real estate | 2019 |
| HNV Fuel Limited | Wholesale & retail | 2025 |
| Hoffer Supplies Limited | Manufacturing | 2019 |
| Holistic Care London Limited | Other services | 2012 |
| Holly Clark Photography Limited | Professional & scientific | 2011 |
| Hollywood Authentic Ltd | Professional & scientific | 2010 |
| Holywood FM Limited | Information & communication | 2007 |
| Home Counties Renovations Limited | Construction | 2026 |
| Honey Hill Management Company Limited | Households | 1981 |
| Honeygold House Ltd | Households | 2012 |
| Hopkin Services Limited | Other services | 2018 |
| Hopsndrops Ltd | Hospitality | 2026 |
| Horbax Limited | Information & communication | 2019 |
| Hornegarth Ltd | Health & social care | 2020 |
| Hot Hoagie Holdings Limited | Financial services | 2017 |
| Hot Hoagie Limited | Hospitality | 2017 |
| Hough H R Ltd. | Administrative & support | 2001 |
| House of Chaat Ltd | Hospitality | 2021 |
| Howbourne Limited | Construction | 1963 |
| HP Orthotics Ltd | Health & social care | 2024 |
| HPS Consulting Ltd | Professional & scientific | 2022 |
| HQ Consultancy Services Limited | Professional & scientific | 2025 |
| HRI Herbal Medicine Ltd | Extraterritorial | 2013 |
| HRS Development Limited | Construction | 2014 |
| HSN Care (Bricket Wood) Limited | Health & social care | 2015 |
| Hsoh Ltd | Real estate | 2019 |
| Hubpay Limited | Information & communication | 2020 |
| Hubpay UK Limited | Financial services | 2025 |
| HUM T DUM T Limited | Wholesale & retail | 1998 |
| Human Infrastructure Ltd | Professional & scientific | 2025 |
| Humphrey-Ingram Carpentry Limited | Information & communication | 2025 |
| Hungry Gourmet Ltd | Professional & scientific | 2024 |
| Hunter Gatherer Limited | Information & communication | 2010 |
| Hurlingham Business Park (Management) Limited | Households | 1987 |
| Huskador Ltd | Professional & scientific | 2013 |
| Hutclub Limited | Wholesale & retail | 2023 |
| HVC (CI) Ltd | Construction | 2017 |
| Hydraulic Lift Solutions Limited | Manufacturing | 2017 |
| I.C. Homes & Property Limited | Real estate | 2004 |
| IAN Scott Consulting Limited | Professional & scientific | 2005 |
| Ibex Capital Solutions Ltd | Agriculture & fishing | 2012 |
| Ibisp Limited | Other services | 2021 |
| Iconix Meadow Hill Ltd | Construction | 2026 |
| ID GDP Ltd | Other services | 2025 |
| Ideal Outlet Ltd | Wholesale & retail | 2024 |
| IDH Lighting Services Limited | Construction | 2014 |
| Idle Moments Ltd | Wholesale & retail | 2020 |
| IG Holdings (Group) Ltd | Financial services | 2023 |
| Ignite Growth LLP | | 2016 |
| Igroup Global Limited | Information & communication | 2021 |
| IHG Limited | Construction | 1980 |
| IHG Mental Health Limited | Professional & scientific | 1982 |
| Ilford Trading Company Limited | Real estate | 2026 |
| Ilhok Limited | Real estate | 2022 |
| ILP Productions Limited | Other services | 2014 |