| Greenbax Ventures Limited | Professional & scientific | 2022 |
| Greencourt RTM Company Limited | Other services | 2007 |
| Greencrest Services Limited | Construction | 2022 |
| Greenenough Ltd | Professional & scientific | 2025 |
| Greener Eco Solutions Limited | Information & communication | 2023 |
| Greenham (Premises) Limited | Professional & scientific | 1930 |
| Greenhaus Studios Limited | Arts & recreation | 2025 |
| Greenhill Courts Limited | Households | 2001 |
| Greenleaf Care & Support Services Ltd | Health & social care | 2026 |
| Greenphoenixenergy Ltd | Construction | 2025 |
| Greenrise Developments Ltd | Construction | 2022 |
| Greenscape Partners LLP | | 2019 |
| Greenshine Services Limited | Administrative & support | 2020 |
| Greenstone Hospitality Limited | Hospitality | 2023 |
| Greenwich (HR) Holdings Limited | Real estate | 2021 |
| Greenwich Car Repairs Limited | Wholesale & retail | 2017 |
| Greenwich Electricians Ltd | Manufacturing | 2020 |
| Greenwich Exchange Limited | Information & communication | 1987 |
| Greenwich Heating Solutions Limited | Construction | 2014 |
| Grevillea Investments Limited | Other services | 1997 |
| Grey Bridge Holdings Limited | Financial services | 2016 |
| Greystone Properties Estate Ltd | Real estate | 2023 |
| Gridside Limited | Information & communication | 2001 |
| Griesel Limited | Professional & scientific | 2010 |
| Grieve Investments Ltd | Professional & scientific | 2013 |
| Grillers Catering Ltd | Hospitality | 2022 |
| Grillery Fish Bar Ltd | Hospitality | 2016 |
| Grillery Fish Bar of Kent Ltd | Hospitality | 2024 |
| Grillus Franchise Ltd | Hospitality | 2022 |
| Grimm Estates Ltd | Real estate | 2026 |
| Grounded Social Ltd | Hospitality | 2020 |
| Group Sigma Limited | Real estate | 1983 |
| Group Soul World Business Ltd | Hospitality | 2019 |
| Grove Plumbing & Heating Ltd | Other services | 2016 |
| Grove Vale Management Company Limited | Households | 2007 |
| GROW3D Ltd | Manufacturing | 2020 |
| Growth Consultant Ltd | Professional & scientific | 2025 |
| Growth Studio Group Ltd | Administrative & support | 2016 |
| Grudio Ltd | Financial services | 2019 |
| Grundfos Water Treatment UK Ltd. | Water & waste | 2014 |
| GS 10 Limited | Transport & logistics | 2018 |
| GS Rail Limited | Construction | 2018 |
| GSP Motors Ltd | Wholesale & retail | 2022 |
| GT Floors Ltd | Construction | 2025 |
| Gtas Consulting Limited | Professional & scientific | 2017 |
| GTL Mortgage Services Ltd | Financial services | 2018 |
| Gtmg Limited | Real estate | 2017 |
| Gtms Hold Ltd | Transport & logistics | 2019 |
| Gtms Holdings Ltd | Transport & logistics | 2018 |
| Gtms Inc Limited | Information & communication | 2025 |
| Guard Hire Ltd | Administrative & support | 2024 |
| Guardians Facilities Management Limited | Households | 2023 |
| Guardpass Limited | Information & communication | 2013 |
| Guarnieri Architects Limited | Professional & scientific | 2005 |
| Gude's Beauty and Wellbeing Ltd | Other services | 2018 |
| Guedes Constructions Limited | Construction | 2026 |
| Guler Tech Ltd | Information & communication | 2024 |
| Gumus AY Limited | Hospitality | 2023 |
| Guoxin Infu Co., Ltd. | Extraterritorial | 2013 |
| Gurajala Business Services Limited | Manufacturing | 2024 |
| Gurkha Cars Ltd | Transport & logistics | 2010 |
| Guru Leisure Limited | Professional & scientific | 2007 |
| Gusha Mukanya Limited | Health & social care | 2011 |
| Gutenstein Limited | Manufacturing | 2024 |
| Gutter Maintenance Tech Ltd | Administrative & support | 2022 |
| Guymajoe Limited | Financial services | 2016 |
| GV Cseh Limited | Transport & logistics | 2014 |
| Gverdet Ltd | Transport & logistics | 2020 |
| GZ Drylining Services Limited | Construction | 2018 |
| H & H Secretarial Services Ltd | Administrative & support | 2025 |
| H K Market Development Limited | Other services | 2005 |
| H Manning Ltd | Professional & scientific | 2023 |
| H P Savvides I.E.T.R. Limited | Wholesale & retail | 1999 |
| H Page Engineering Services Limited | Extraterritorial | 2011 |
| H Page Limited | Extraterritorial | 2011 |
| H&A Rehab Case Management Services Limited | Other services | 2023 |
| H&D Property Management Ltd | Real estate | 2020 |
| H&H Solutions PVT Limited | Professional & scientific | 2016 |
| H&Hmediaandentertainment Ltd | Professional & scientific | 2022 |
| H&K Bromley Limited | Wholesale & retail | 2025 |
| H&N CC Limited | Administrative & support | 2020 |
| H. & E. Cater Contracts Limited | Real estate | 1976 |
| H. H. Land Limited | Households | 2002 |
| H. J. Johnston Limited | Construction | 2011 |
| H.& E.Waters Limited | Wholesale & retail | 1931 |
| H.D. Blackie Limited | Financial services | 2023 |
| H.E. Howe (Southern) Limited | Financial services | 1993 |
| H2H Marketing Limited | Professional & scientific | 2018 |
| H2O GAS Plumbing and Heating Ltd | Construction | 2016 |
| H48 Group Ltd | Professional & scientific | 2025 |
| H5 Advisory Limited | Professional & scientific | 2026 |
| Haan Corporation Ltd | Wholesale & retail | 2022 |
| Haarp Building Ltd | Construction | 2022 |
| HAB Building Solution Ltd | Construction | 2017 |
| Habaté Ltd | Wholesale & retail | 2025 |
| Hackney Flower Show CIC | Public administration | 2024 |
| Hadleigh Barbers Limited | Other services | 2021 |
| Hadleigh Brentwood RTM Company Limited | Households | 2026 |
| Hadleigh Court (Chingford) Limited | Households | 1987 |
| HAE Mortgages Ltd | Financial services | 2021 |