| Guidance Media Distribution Limited | Information & communication | 2009 |
| Guildprop Limited | Professional & scientific | 2018 |
| Guntrisoft Limited | Information & communication | 2000 |
| Gupster Consultancy Ltd | Professional & scientific | 2020 |
| Gupta Anaesthetic Solutions (GAS) Ltd | Health & social care | 2019 |
| Guru Mahima | Other services | 2023 |
| Guru Technologies Ltd | Information & communication | 2011 |
| Gusaway Ltd | Wholesale & retail | 2025 |
| GVD Accountants Limited | Professional & scientific | 2014 |
| GW Productions Limited | Information & communication | 2025 |
| GWB Scaffold Ltd | Construction | 2025 |
| Gym Club Ltd | Arts & recreation | 2014 |
| GYM5 Limited | Arts & recreation | 2013 |
| Gypcraft Drylining Contractors Limited | Construction | 2001 |
| Gypcraft Holdings Limited | Financial services | 2016 |
| Gàire MÒR Ltd | Information & communication | 2024 |
| H & Askham Ltd | Construction | 2005 |
| H & B Care Limited | Health & social care | 2022 |
| H & Clarke Electrical Limited | Construction | 2013 |
| H & O Brothers Ltd | Hospitality | 2025 |
| H Bellingham Limited | Wholesale & retail | 2009 |
| H Building & Plumbing Limited | Construction | 2023 |
| H Cabinetry & Woodwork Ltd | Extraterritorial | 2026 |
| H H Poker Limited | Other services | 2009 |
| H W Carpentry & Building Ltd | Construction | 2022 |
| H&D Electric Limited | Manufacturing | 2018 |
| H&J Residentials Ltd | Real estate | 2016 |
| H&O Developments Limited | Construction | 2005 |
| H&O Estates Limited | Real estate | 2017 |
| H&O Management Limited | Construction | 2014 |
| H&W Medical Limited | Health & social care | 2016 |
| H.A.S.K Living Ltd | Real estate | 2023 |
| H2M Consultancy Limited | Information & communication | 2016 |
| H2M Properties Ltd | Real estate | 2020 |
| H4CK Performance Ltd | Wholesale & retail | 2024 |
| Habitat Buildings Limited | Real estate | 2025 |
| Habitat Housing Limited | Real estate | 2024 |
| Hache Property Limited | Real estate | 2024 |
| Haines & SON Roofing Specialists Ltd | Construction | 2022 |
| Hair @ NO 75 Limited | Other services | 2015 |
| Hair Asylum Ltd | Other services | 2019 |
| Hair by Sara Limited | Other services | 2012 |
| Halcyon Digital Ltd | Information & communication | 2025 |
| Halcyon Franchising Group Ltd | Administrative & support | 2021 |
| Hale Electrics Limited | Construction | 2013 |
| Hall & Sawyer Ltd | Wholesale & retail | 2018 |
| Halo Crunch Ltd | Wholesale & retail | 2025 |
| Haloure Limited | Wholesale & retail | 2025 |
| Haloye Specialist Ltd | Health & social care | 2023 |
| Hamilton Villiers Ltd | Wholesale & retail | 2016 |
| Hanan Capital Ltd | Real estate | 2025 |
| Hancock & Campbell Ltd | Professional & scientific | 2022 |
| Hank Agency Ltd | Health & social care | 2020 |
| Hanke Design UK Ltd | Manufacturing | 2025 |
| Hannah Barlow Limited | Professional & scientific | 2017 |
| Hannahjosh Limited | Arts & recreation | 2024 |
| Hanns.G Enterprises Ltd | Administrative & support | 2009 |
| Haoran Enterprises Limited | Hospitality | 2019 |
| Happy Punter Ltd | Hospitality | 2020 |
| Happy Wingz Ltd | Hospitality | 2025 |
| Haque Ahmed Properties Limited | Real estate | 2016 |
| Hara Properties Investments Ltd | Real estate | 2025 |
| Harchly Holdings Limited | Real estate | 2019 |
| Harding Capital Ltd | Financial services | 2026 |
| Harjoh Limited | Professional & scientific | 2012 |
| Harlands Consulting Limited | Professional & scientific | 2025 |
| Harlequins Theatre School S&S Limited | Administrative & support | 2016 |
| Harley Electrical Contractors Limited | Construction | 2013 |
| Harley Street Chiropractors Ltd | Health & social care | 2020 |
| Harloberg Limited | Professional & scientific | 2014 |
| Harlu Consulting Ltd | Professional & scientific | 2016 |
| Harmony Contracts Limited | Information & communication | 2000 |
| Harmony Foot and LEG Solutions Limited | Health & social care | 2025 |
| Harmony Scans Limited | Health & social care | 2026 |
| Haron Consulting Limited | Information & communication | 2016 |
| Harringtons Architectural Limited | Manufacturing | 2022 |
| Harris Electrical Contractor (Kent) Limited | Construction | 2018 |
| Harris Ventures Limited | Real estate | 1988 |
| Harrison Quarters Construction Ltd | Construction | 2024 |
| Harrisons Electrical Services Limited | Construction | 2009 |
| Harrow-Corp Limited | Real estate | 2024 |
| Harrowhurst Investments Limited | Real estate | 1982 |
| Hartley & Dark Electric Limited | Manufacturing | 1963 |
| Harvestbank Ltd | Professional & scientific | 2010 |
| Hask Living SA Ltd | Hospitality | 2025 |
| Hastings Road Limited | Real estate | 2019 |
| Haswell Holdings Limited | Real estate | 2001 |
| Haswell Properties Limited | Real estate | 2016 |
| Havard GAS Services Limited | Construction | 2021 |
| Hawkridge Developments Ltd | Construction | 2026 |
| Hayfield Landscapes Limited | Administrative & support | 2017 |
| Hayworth Coopers Ltd | Professional & scientific | 2009 |
| Hazel Nails Limited | Other services | 2024 |
| HB Food and Drink Limited | Hospitality | 2023 |
| HB Health Comms Limited | Information & communication | 2016 |
| HB London Enterprises Ltd | Wholesale & retail | 2018 |
| HB Plastering (London) Limited | Construction | 2016 |
| HCH Homes Limited | Real estate | 2025 |
| HCI Data Limited | Information & communication | 1998 |
| HD GAD Ltd | Wholesale & retail | 2018 |