| Galldris Rail Limited | Construction | 2015 |
| Galldris Services Ltd | Construction | 2010 |
| Galldris Structures Limited | Construction | 2005 |
| Galleria Emporium Limited | Other services | 2001 |
| Gallery Capital Investments Limited | Construction | 2025 |
| Gallery Gifts Limited | Wholesale & retail | 1981 |
| Galleywood Pharmacy Limited | Wholesale & retail | 2002 |
| Galliard Heritage Property Ltd | Real estate | 2025 |
| Gama Investments Ltd | Real estate | 2011 |
| Game Box London Ltd | Wholesale & retail | 2012 |
| Game My FAN Limited | Information & communication | 2025 |
| Gameset Limited | Extraterritorial | 2005 |
| GAMETECH4U Limited | Wholesale & retail | 2021 |
| Gamma Estates Limited | Real estate | 2025 |
| Gamma Secure Systems Limited | Information & communication | 1987 |
| Gammov Consultancy Limited | Professional & scientific | 2018 |
| Gana Properties Ltd | Real estate | 2020 |
| Gana Village Ltd | Hospitality | 2025 |
| Ganatrao Property Services Ltd | Real estate | 2022 |
| Gandaya Limited | Financial services | 2018 |
| Gander Property Management Limited | Real estate | 2020 |
| Gandiva Medical Consulting Ltd | Health & social care | 2025 |
| Gandy Street Investments Limited | Real estate | 1995 |
| Ganedya Limited | Hospitality | 2017 |
| Ganeshaonline UK Limited | Wholesale & retail | 2022 |
| Gangamaiyaaa Ltd | Wholesale & retail | 2019 |
| Ganymede Consulting Services Limited | Information & communication | 2010 |
| GAP Consulting (UK) Limited | Professional & scientific | 2009 |
| GAP Medical Ltd | Health & social care | 2023 |
| GAR & Sons Limited | Construction | 2019 |
| Garda Global Solutions Limited | Other services | 2022 |
| Garda House RTM Company Limited | Households | 2020 |
| Garden Projects Design Ltd | Construction | 2021 |
| Garden Rooms &Building Service Ltd | Construction | 2025 |
| Gardinia Estates Limited | Real estate | 2023 |
| Garlands Management Limited | Households | 1986 |
| Garner & Parni Limited | Real estate | 2021 |
| Garp Services Ltd | Administrative & support | 2025 |
| Garrick Hendon Management Co. Limited | Households | 1987 |
| Garricks Development Ltd | Real estate | 2015 |
| Garricks Investment Properties Limited | Real estate | 2025 |
| Garuda Investama Ltd | Financial services | 2025 |
| Gary & Milena Harris LLP | | 2026 |
| GAS Safe Service Ltd | Construction | 2012 |
| GAS Sparks Ltd | Construction | 2023 |
| Gastco Ltd | Financial services | 2020 |
| Gastmo Limited | Real estate | 2019 |
| Gastonia's Ltd | Manufacturing | 2023 |
| Gasworks Plumbing and Heating Limited | Construction | 2023 |
| GAT Construction Ltd | Construction | 2020 |
| Gate Aero Limited | Wholesale & retail | 2018 |
| Gate Control Limited | Construction | 2009 |
| Gated Metro Ltd | Professional & scientific | 2024 |
| Gatehead Properties Limited | Real estate | 2015 |
| Gates of Vanitas Limited | Wholesale & retail | 2022 |
| Gates Trading Ltd | Wholesale & retail | 2021 |
| Gateset Ltd | Manufacturing | 2022 |
| Gateway 2 London Limited | Extraterritorial | 2013 |
| Gateway Capital Investments Ltd | Real estate | 2020 |
| Gateway Optimum Services Limited | Extraterritorial | 2013 |
| Gateway Television Limited | Information & communication | 2009 |
| Gateways Global Ltd | Wholesale & retail | 2025 |
| Gather Digital AI Limited | Information & communication | 2025 |
| Gattaca Technologies Ltd | Information & communication | 2006 |
| Gatundus Limited | Manufacturing | 2020 |
| Gatwick BB (UK) Ltd | Hospitality | 2023 |
| Gaudineto Ltd | Hospitality | 2026 |
| Gaudium Vitae Ltd | Health & social care | 2025 |
| Gaudiya Holdings Ltd | Real estate | 2023 |
| Gautam Products Ltd | Wholesale & retail | 2025 |
| Gautam ZEN UK Ltd | Wholesale & retail | 2019 |
| Gavan Roofing Ltd | Construction | 2016 |
| Gavin Anthony Ltd | Other services | 2020 |
| Gavin Oliver Associates Limited | Professional & scientific | 2017 |
| Gavonix Manufacturing Ltd | Manufacturing | 2022 |
| Gavriel Hairdressing Limited | Other services | 2003 |
| Gavriliuc Ltd | Construction | 2018 |
| Gayathri Jewellery Ltd | Manufacturing | 2022 |
| Gayatri Food Group Limited | Wholesale & retail | 2016 |
| Gaylord Focker Limited | Professional & scientific | 2022 |
| Gayton Court (Harrow) Limited | Households | 1972 |
| Gayton Road (Management Company) Limited | Households | 1983 |
| Gayton Road (Management Company) Phase II Limited | Households | 1984 |
| Gayways Ltd | Manufacturing | 2008 |
| Gazania Restaurant Limited | Hospitality | 2016 |
| Gazelle Coach Services Ltd | Transport & logistics | 2017 |
| Gazoline Ltd | Wholesale & retail | 2020 |
| GB Building Services Ltd | Construction | 2015 |
| GB Dancesport Ltd | Arts & recreation | 2020 |
| GB Elite Ltd | Other services | 2011 |
| GB Hybrid Parts Ltd | Wholesale & retail | 2023 |
| GB Optics Limited | Health & social care | 2010 |
| GB Plant Operator Ltd | Construction | 2025 |
| GB Stock Limited | Real estate | 2025 |
| GB Treats Limited | Hospitality | 2022 |
| GB1711001B Limited | Financial services | 2017 |
| GB1803001B Limited | Financial services | 2017 |
| GB1805001B Limited | Financial services | 2018 |
| GB1812001B Limited | Financial services | 2018 |
| GB1901001B Limited | Financial services | 2018 |