| Gourmet Food Direct Ltd | Hospitality | 2017 |
| Grade Accelerator Academy Ltd | Education | 2023 |
| Gray Hills & Co Ltd | Professional & scientific | 1996 |
| Great Learners Trust | Education | 2014 |
| Green & Wild Plants Limited | Wholesale & retail | 2024 |
| Green Park Court Management Association Limited | Households | 1973 |
| Greenside Finance Insights Ltd | Professional & scientific | 2017 |
| Greyley Consulting Ltd | Professional & scientific | 2025 |
| Grimms Dyke (Liberty) Estates Limited | Real estate | 1978 |
| Grover Great Missenden Limited | Wholesale & retail | 2024 |
| Growth Accelerator Services Ltd | Professional & scientific | 2023 |
| Gulliford Real Estate Solutions Limited | Professional & scientific | 2023 |
| Gunter Rieser Ltd | Wholesale & retail | 2017 |
| H.G.Bird(South Heath)Limited | Real estate | 1954 |
| Hallux Solutions Ltd | Professional & scientific | 2020 |
| Hampden Common Lane Management Company | Households | 2023 |
| Hampden Group Management Limited | Professional & scientific | 1972 |
| Hampden Holdings Limited | Professional & scientific | 1995 |
| Hampden Insurance Holdings Limited | Professional & scientific | 1972 |
| Hampden PLC | Professional & scientific | 1994 |
| Hampden Private Capital Limited | Financial services | 2008 |
| Hampden Private Office Limited | Financial services | 2016 |
| Hampden Property Development Limited | Professional & scientific | 2007 |
| Hampden SPV (NO. 1) Limited | Financial services | 2014 |
| Hardie Consulting Ltd | Professional & scientific | 2010 |
| Hare Lane END Residents Association Limited(The) | Professional & scientific | 1983 |
| Haris Gray Electrical Building Services Limited | Construction | 2019 |
| Hart Business Systems Limited | Information & communication | 1989 |
| Havex Limited | Wholesale & retail | 2013 |
| Havides Limited | Wholesale & retail | 2025 |
| Health and Lifestyle Ltd | Other services | 2015 |
| Health Ventures Limited | Professional & scientific | 2000 |
| Healthy Balance Clinics Limited | Health & social care | 2002 |
| Heart Centred Care Ltd | Health & social care | 2026 |
| Heath END Land Limited | Extraterritorial | 2012 |
| Heath House Residents Association Limited | Households | 1980 |
| Helicraft Logistics Limited | Administrative & support | 2017 |
| Helimatrix Limited | Wholesale & retail | 2025 |
| Heron Holding Ltd | Information & communication | 2015 |
| Heversham Ltd | Extraterritorial | 2025 |
| Hexden Ltd | Professional & scientific | 2023 |
| Hidayah Labs Ltd | Information & communication | 2026 |
| Hildreths (China & Hardware) Limited | Wholesale & retail | 1966 |
| Hillingdon Gardens Management Company Limited | Households | 2007 |
| HJA Risk Solutions Limited | Financial services | 2024 |
| Holmers Court Management Company Limited | Households | 1993 |
| Honorwood Ltd | Construction | 2024 |
| HP14 Fitness Limited | Arts & recreation | 2024 |
| HSM Finance Limited | Financial services | 2015 |
| Hudson-Baker Brands Ltd | Extraterritorial | 2022 |
| Hyde Services Limited | Professional & scientific | 1990 |
| Hydewood Properties Ltd | Real estate | 2018 |
| Hydra Properties Limited | Hospitality | 2019 |
| I J K Electrical Solutions Ltd | Manufacturing | 2016 |
| IA Consulting Group Ltd | Other services | 2019 |
| IAN Mead & Co Ltd. | Professional & scientific | 1965 |
| Icops Limited | Information & communication | 2015 |
| Idea Capital Limited | Real estate | 2004 |
| IGM Properties Ltd | Real estate | 2023 |
| Inateck Technology (UK) Ltd | Wholesale & retail | 2017 |
| Indigonet Ltd | Information & communication | 2011 |
| Ingul-M Ltd | Construction | 2022 |
| Instacomm Technologies Ltd | Information & communication | 2020 |
| Integrity Professional Solutions Limited | Administrative & support | 2022 |
| International ADS Ltd | Professional & scientific | 2017 |
| Inthecircl Ltd | Administrative & support | 2026 |
| Intranet Technologies Limited | Information & communication | 1997 |
| Involve Training & Development Limited | Professional & scientific | 2004 |
| Ironroad Advisory Limited | Professional & scientific | 2018 |
| Isatec Limited | Information & communication | 1996 |
| James Callicott Designs Ltd. | Administrative & support | 2019 |
| Jamescampion Ltd | Professional & scientific | 2022 |
| Jane Knight Vintage Ltd | Wholesale & retail | 2024 |
| Janko Tennis Ltd | Arts & recreation | 2018 |
| Jaybex Ltd | Administrative & support | 2012 |
| Jeffery Harrison & Hide Limited | Professional & scientific | 2019 |
| JJW Geoconsulting Ltd | Professional & scientific | 2024 |
| JM Rogers Building Services Ltd | Construction | 2025 |
| JMN Solutions Limited | Manufacturing | 2006 |
| JO Bawden Limited | Other services | 2017 |
| Jonathan Allen Recording Limited | Information & communication | 2018 |
| JWS Creative Ltd. | Professional & scientific | 2015 |
| K Dallas Designs Ltd | Wholesale & retail | 2023 |
| K&K Investing Limited | Extraterritorial | 2025 |
| Kauai Limited | Administrative & support | 2004 |
| KD Services London Limited | Wholesale & retail | 2025 |
| Kennards Court Apartments Limited | Households | 2010 |
| KIN Studio Production Ltd | Information & communication | 2025 |
| Kinetic GB Limited | Professional & scientific | 2006 |
| Kinetra Ltd | Information & communication | 2024 |
| Kings Church Homes Limited | Real estate | 2015 |
| Kingsmead View (NHE) Management Company Limited | Households | 2008 |
| Kirkleven Estates Ltd | Construction | 2011 |
| Kleinfield Limited | Professional & scientific | 2018 |
| Klst Properties Ltd | Real estate | 2022 |
| Knowle Court Management Limited | Households | 1993 |
| Knowle Inns Limited | Hospitality | 2008 |
| Koha Consulting Ltd | Administrative & support | 2021 |
| Koorator Ltd | Information & communication | 2023 |
| KR4 Ltd | Professional & scientific | 2022 |