| Harper Tait Fine Jewellery Limited | Wholesale & retail | 2017 |
| Harribert East Security Services Limited | Other services | 1992 |
| Harric Consulting Limited | Information & communication | 2025 |
| Harrier Group Holdings Limited | Financial services | 2025 |
| Harrier Group Limited | Real estate | 2019 |
| Harris & Hewett Limited | Wholesale & retail | 2005 |
| Harris Consulting Ltd | Professional & scientific | 2026 |
| Harris Trading Group Limited | Other services | 2022 |
| Harrison Property Services Ltd | Construction | 2016 |
| Harrod's Electrical Services Ltd | Construction | 2019 |
| Harry’S Sweets & Treats Ltd | Wholesale & retail | 2025 |
| Hart Plumbing & Heating Services Limited | Construction | 2022 |
| Hartfelt Crafts Ltd | Wholesale & retail | 2025 |
| Harvey London Ltd | Construction | 2023 |
| Harvie Groundwork Limited | Construction | 2006 |
| Harwich Breaks Ltd | Real estate | 2023 |
| Harwood Marks Limited | Wholesale & retail | 2025 |
| Hashtag United Football Club Limited | Arts & recreation | 2018 |
| Hashtag United Ltd | Arts & recreation | 2017 |
| Hashtag United Youth FC Limited | Education | 2023 |
| Hashtag Women Limited | Arts & recreation | 2025 |
| Hasyim Trade Ltd | Transport & logistics | 2025 |
| Hatip 2019 Ltd | Hospitality | 2019 |
| Hatt Homes Limited | Real estate | 2020 |
| Haulage Power Ltd | Transport & logistics | 2023 |
| Haveli Furnitures Ltd | Wholesale & retail | 2024 |
| Haven Faces Limited | Wholesale & retail | 2016 |
| Haven of Rest | Other services | 2011 |
| Havilah Energy Ltd | Administrative & support | 2019 |
| Havilah Holdings Limited | Wholesale & retail | 2019 |
| HAW Waste Limited | Water & waste | 2025 |
| Hawkes Engineers UK Limited | Manufacturing | 2011 |
| Hawkes & Co Electrical Services Ltd | Construction | 2019 |
| Hawkes Refrigeration Engineers Limited | Manufacturing | 2011 |
| Hawley Property Services Limited | Administrative & support | 2017 |
| Hawtal Whiting Ltd | Professional & scientific | 2009 |
| Hayah Car Traders Ltd | Administrative & support | 2015 |
| Hayati Distro Limited | Wholesale & retail | 2025 |
| Hayden Dixon Limited | Health & social care | 2021 |
| Haydock Finance NO.2 Limited | Financial services | 2020 |
| Hayes Fire Services Ltd | Public administration | 2026 |
| Hayley Loren Ltd | Professional & scientific | 2017 |
| Haynes Building & Development Limited | Real estate | 2011 |
| Hazel & BOW Ltd | Administrative & support | 2023 |
| HB Electrics Ltd | Construction | 2021 |
| HC Trading Limited | Wholesale & retail | 2023 |
| HCT Plumbing and Heating Solutions Ltd | Construction | 2024 |
| Hdgg Ltd | Administrative & support | 2025 |
| Headley Property Investments Limited | Real estate | 2020 |
| Headlong Property Ltd | Real estate | 2025 |
| Headrush Hair Salon Ltd | Other services | 2013 |
| Heads Investments Limited | Real estate | 2020 |
| Headway Construction Services Limited | Construction | 2022 |
| Heal Cleaning Group Limited | Administrative & support | 2025 |
| Health Sync Limited | Health & social care | 2023 |
| Healthcare Consultation Ltd | Real estate | 2018 |
| Healthcare Fire Safety Services Ltd | Public administration | 2023 |
| Healthmed BIO Consulting Ltd | Health & social care | 2025 |
| Healthsapphire Ltd | Information & communication | 2025 |
| Healthsense Solutions Ltd | Financial services | 2020 |
| Heard Demolition Ltd | Construction | 2018 |
| Heard Environmental Services Limited | Extraterritorial | 2006 |
| Heard Plant Hire Limited | Administrative & support | 2018 |
| Heart Care PH Ltd | Health & social care | 2020 |
| Heart Electrical Services Ltd | Construction | 2015 |
| Heartway Care Services Limited | Health & social care | 2026 |
| HEAT2ON Limited | Construction | 2023 |
| Heathway Halal Meat & Fish Ltd | Wholesale & retail | 2024 |
| Heating& Plumbing Pros Ltd | Construction | 2025 |
| HEATPUMPS4POOLS Limited | Administrative & support | 2011 |
| Heatwave Plumbing Solutions Ltd | Construction | 2024 |
| Heavy Metal Hippie Music Ltd | Professional & scientific | 2020 |
| Hebunlams World Limited | Extraterritorial | 2023 |
| HEC Services Ltd | Construction | 2017 |
| Hedgemoor Court RTM Company Limited | Extraterritorial | 2026 |
| Heeterem Ltd | Wholesale & retail | 2025 |
| Helcenor Ltd | Construction | 2022 |
| Helda Services Ltd | Health & social care | 2015 |
| Helen Warner Limited | Professional & scientific | 2007 |
| Helenkay Ltd | Wholesale & retail | 2026 |
| Hello London International Group Ltd | Wholesale & retail | 2026 |
| Helloyouva Limited | Professional & scientific | 2022 |
| Hemayet and Sons Ltd | Real estate | 2021 |
| Hemingway Interiors Limited | Construction | 2021 |
| Hemmells Management Company Limited | Extraterritorial | 1988 |
| Hemmells Park Limited | Real estate | 2005 |
| Hendas Ltd | Construction | 2026 |
| Henderson & Forbes Limited | | 2013 |
| Henderson Driveways Limited | Construction | 2018 |
| Henkoff Limited | Transport & logistics | 2023 |
| Henry Cave Limited | Wholesale & retail | 2004 |
| Henyor Services Limited | Construction | 2010 |
| HER Solutions Ltd | Other services | 2022 |
| Heritage Book Haven Ltd | Wholesale & retail | 2025 |
| Heritage Connect C.I.C. | Education | 2023 |
| Heritage Homes Roofing & Building Contractors Ltd | Construction | 2025 |
| Heritagestone Renovate Limited | Other services | 2014 |
| Hermes & Mercury Ltd | Other services | 2024 |
| Hermworks Limited | Construction | 2017 |
| Herojenny Beauty Services Ltd | Other services | 2024 |