| Gary Bennetton Limited | Professional & scientific | 2007 |
| Gary Linton Services (International) Limited | Professional & scientific | 2011 |
| Gary W Smart Ltd | Construction | 2025 |
| GAS and Water Experts Limited | Construction | 2023 |
| GAS Bright Limited | Construction | 2021 |
| GAS Half Full Limited | Health & social care | 2019 |
| GAS Wave Ltd | Construction | 2023 |
| Gascare(Southampton) Limited | Professional & scientific | 1982 |
| Gassed UP Heating Ltd | Construction | 2021 |
| Gastec Heating Ltd | Construction | 2019 |
| Gaswarm Heating and Mechanical Ltd | Construction | 2018 |
| Gaswarm Ltd | Extraterritorial | 2023 |
| Gaswise Heating Engineers Limited | Professional & scientific | 2006 |
| Gate House Southampton Limited | Real estate | 2013 |
| Gatecote Limited | Information & communication | 2024 |
| Gateway Building Services Limited | Administrative & support | 2008 |
| Gateway to the World Limited | Professional & scientific | 2019 |
| Gather & Glow Ltd | Administrative & support | 2026 |
| Gavin Noke Limited | Construction | 2018 |
| Gaviota (UK) Ltd | Other services | 2023 |
| Gaysha Limited | Construction | 2005 |
| GAZIANTEP22 Ltd | Hospitality | 2023 |
| GB Animation Ltd | Information & communication | 2018 |
| GB Burga Limited | Hospitality | 2018 |
| GB Finance Advisory Ltd | Professional & scientific | 2025 |
| GB Moore Ltd | Wholesale & retail | 2024 |
| GB Wine Consultancy Limited | Hospitality | 2011 |
| GBD Hampshire Limited | Construction | 2025 |
| Gbgr Bikes Ltd | Wholesale & retail | 2016 |
| Gbhq Group Ltd | Wholesale & retail | 2025 |
| GBI 25 Ltd | Transport & logistics | 2025 |
| GBM Safety Ltd | Health & social care | 2025 |
| GC Healthcare Limited | Health & social care | 2012 |
| GC Transport (Southern) Limited | Transport & logistics | 2013 |
| GCM Consulting Limited | Information & communication | 1999 |
| GCP Enterprises Limited | Health & social care | 2024 |
| GCS Accountants Ltd | Professional & scientific | 2008 |
| Gcse Toolkit Limited | Education | 2025 |
| Gczm Ltd | Extraterritorial | 2024 |
| GD Carpentry Ltd | Construction | 2025 |
| GD Natcap Ltd | Professional & scientific | 2016 |
| GDF Energy Ltd | Construction | 2022 |
| Gdjr Limited | Transport & logistics | 2004 |
| GDS Building and Maintenance Limited | Construction | 2015 |
| Geanina Trans Limited | Transport & logistics | 2021 |
| Geany Vanessa Ltd | Transport & logistics | 2025 |
| Gearcall International Limited | Real estate | 1981 |
| Gecko Graphics Limited | Professional & scientific | 2013 |
| Gecko IT Services Ltd | Information & communication | 2026 |
| Gecko Representation Services Ltd | Administrative & support | 2009 |
| Geddes Warehouse Limited | Administrative & support | 2008 |
| GEE Capital Ltd | Wholesale & retail | 2024 |
| GEE Expandly Ltd | Information & communication | 2023 |
| Geeco Private Hire Ltd | Transport & logistics | 2023 |
| Geecon Properties Ltd | Real estate | 2024 |
| Geeman Sushi Ltd | Hospitality | 2024 |
| Gejd Holdings Limited | Financial services | 2022 |
| Gelato Cafes Limited | Hospitality | 2014 |
| Gelbix Limited | Professional & scientific | 2010 |
| GEM Studio Properties Ltd | Households | 2025 |
| Gemba Design Solutions Ltd | Professional & scientific | 2023 |
| Gemeny Group Transport Ltd | Transport & logistics | 2018 |
| Gemini Commercial Holdings Ltd | Transport & logistics | 2024 |
| Gemini Landscapes Ltd | Administrative & support | 2008 |
| Gemini Roofing & Cladding Limited | Construction | 2012 |
| Gemini Scaffolding Division Ltd | Construction | 2023 |
| Gemini UK Group Ltd | Construction | 2025 |
| Geminiuk Limited | Construction | 2025 |
| GEN II Group Services (UK) Limited | Administrative & support | 2021 |
| Gen-Y Company Ltd | Other services | 2024 |
| Genco Restaurant & Bar Ltd | Hospitality | 2019 |
| General Building Services (Southampton) Limited | Construction | 2007 |
| General Estates Company Limited | Hospitality | 1900 |
| General Quality Care Ltd | Health & social care | 2014 |
| Genertek Power Limited | Professional & scientific | 2017 |
| Genesis Flowers Limited | Wholesale & retail | 1994 |
| Genesis Rentals 2 Limited | Real estate | 2026 |
| Genesis Rentals Limited | Real estate | 2013 |
| Genesis Rentals Properties LLP | | 2022 |
| Genesis Worn Limited | Wholesale & retail | 2022 |
| Genesisound Limited | Information & communication | 2024 |
| Genie Automations Ltd | Information & communication | 2026 |
| Genie Escapes Ltd | Administrative & support | 2026 |
| Genie Powers Limited | Arts & recreation | 2019 |
| Genologix Labs Ltd | Professional & scientific | 2023 |
| GENR8 Homes Ltd | Construction | 2024 |
| Gens UNA Investments LLP | | 2011 |
| Gentle Support Ltd | Health & social care | 2026 |
| Gentlemen's League @NO18 Ltd | Other services | 2018 |
| Gents Barber Club Limited | Other services | 2019 |
| Genuine Care Agency Limited | Administrative & support | 2021 |
| Genuine Edge Consulting Limited | Professional & scientific | 2021 |
| Genuine Tickets Ltd | Wholesale & retail | 2019 |
| Genz Driving School Limited | Education | 2025 |
| GEO Code LLP | | 2019 |
| GEO Specialty Chemicals UK Limited | Manufacturing | 2011 |
| Geoff SIM Coach and Mentor Limited | Other services | 2018 |
| Geoffrey Dashwood Limited | Arts & recreation | 2004 |
| Geoplace LLP | | 2010 |
| Georganics Ltd | Manufacturing | 2014 |