| Garlto Limited | Real estate | 2025 |
| Garrett Farriery Services Limited | Agriculture & fishing | 2015 |
| Garsdon Limited | Construction | 2016 |
| Garuda Courier Limited | Transport & logistics | 2026 |
| Garvie Medical Services Ltd | Health & social care | 2024 |
| Gary Brain Limited | Construction | 2013 |
| Gary Marshall Building Services Limited | Construction | 2018 |
| GAS & Go Limited | Wholesale & retail | 1998 |
| GAS Code Limited | Construction | 2024 |
| GAS Path Analysis Limited | Information & communication | 1997 |
| Gascoigne & Gillett Investments Limited | Real estate | 2021 |
| Gasfirm Ltd | Construction | 2025 |
| Gaskarth Investments Limited | Financial services | 2024 |
| Gasson Costing Limited | Professional & scientific | 2002 |
| Gastech Wilts Ltd | Construction | 2013 |
| Gastrocore Ltd | Information & communication | 2026 |
| Gate Services T/A SAM Floor Care Limited | Administrative & support | 2025 |
| Gateshead Electric Forecourt Ltd | Energy | 2019 |
| Gateway Church Swindon | Other services | 2008 |
| Gateway Medical Ltd | Professional & scientific | 2019 |
| Gattenby Procurement Services Ltd | Professional & scientific | 2014 |
| Gatwick Electric Forecourt Ltd | Energy | 2020 |
| Gauchan Properties Ltd | Real estate | 2026 |
| Gavin Quigley Limited | Health & social care | 2011 |
| GB BG Homes Limited | Professional & scientific | 2006 |
| GB Construct Ltd | Construction | 2023 |
| GB Cooker Spares (2012) Ltd | Wholesale & retail | 2012 |
| GB Enterprise Capital Limited | Financial services | 2016 |
| GB Tables Ltd | Manufacturing | 2025 |
| Gbbart Ltd | Transport & logistics | 2025 |
| GBK Care Ltd | Health & social care | 2014 |
| GBR Builders Ltd | Administrative & support | 2025 |
| GC Airport Transfers LLP | | 2016 |
| GC Marketing Limited | Arts & recreation | 2021 |
| GC Property Solutions Limited | Financial services | 2022 |
| GCJ Counselling Limited | Health & social care | 2025 |
| GCM Property Limited | Real estate | 2013 |
| GCR Corporation Limited | Construction | 2025 |
| GCR Security 100 Limited | Real estate | 2025 |
| GCR Security 200 Limited | Real estate | 2025 |
| GCS Developers Ltd | Real estate | 2025 |
| GD Cars (Swindon) Limited | Wholesale & retail | 2017 |
| GD259 Ltd | Hospitality | 2025 |
| GDP & Quality Matters Ltd | Professional & scientific | 2018 |
| GDS Group Limited | Professional & scientific | 2000 |
| Gear Shifters Ltd | Transport & logistics | 2018 |
| Gearup Driving Solutions Limited | Transport & logistics | 2025 |
| Gebm Limited | Information & communication | 2019 |
| Gecko Polished Concrete Ltd | Administrative & support | 2017 |
| Gecko Properties Ltd | Real estate | 2021 |
| Geek Beach Limited | Administrative & support | 2009 |
| Geekskyai Limited | Information & communication | 2025 |
| Geeky Details Ltd | Wholesale & retail | 2025 |
| Geelekopf Lettings Ltd | Real estate | 2024 |
| Geelekopf Property Ltd | Real estate | 2022 |
| Geen Car Wash Ltd | Other services | 2023 |
| Geidans Services Ltd | Information & communication | 2019 |
| Geidans Solutions Ltd | Information & communication | 2009 |
| GEL Studios Ltd | Information & communication | 2013 |
| Gelato Amore MIO Ltd | Manufacturing | 2018 |
| GEM Airbnb Ltd | Households | 2026 |
| GEM Electrical (Swindon) Limited | Construction | 2017 |
| Gemaig Arts LLP | | 2023 |
| Gemini Clinical Research Limited | Professional & scientific | 2015 |
| Gemma Nails Studio Limited | Other services | 2022 |
| Gems Beauty Swindon Limited | Other services | 2024 |
| Gemstone Consultancy Services Ltd | Other services | 2017 |
| Genco Male Emporium Limited | Wholesale & retail | 2006 |
| Gender, Education, Environment and Technology (Geet) Consult Ltd | Professional & scientific | 2024 |
| Genematic Ltd | Information & communication | 2026 |
| General Life UK Limited | Wholesale & retail | 2025 |
| Generatedrinks Limited | Manufacturing | 2015 |
| Generation Group Holdings Limited | Financial services | 2023 |
| Generation Group SW Limited | Transport & logistics | 2019 |
| Generative Technologies Ltd | Information & communication | 2024 |
| Generous Hands Care Ltd | Health & social care | 2022 |
| Genesis CZ Ltd | Transport & logistics | 2010 |
| Genesis Homes Estates & Investments Limited | Real estate | 2025 |
| Genesis Horses Ltd | Agriculture & fishing | 2025 |
| Genesouza Limited | Health & social care | 2026 |
| Genius Fillers Ltd | Wholesale & retail | 2023 |
| Genius Move Limited | Real estate | 2023 |
| Geniuscoco Ltd | Hospitality | 2024 |
| Genosystems Limited | Wholesale & retail | 2002 |
| Gensmile Dental Care Limited | Health & social care | 2015 |
| Gensmile Limited | Professional & scientific | 2014 |
| Genzy Limited | Wholesale & retail | 2025 |
| GEO Partitions Limited | Construction | 2019 |
| GEO SU Services Ltd | Health & social care | 2020 |
| Geodata Labs Limited | Information & communication | 2024 |
| Geomove Activewear Ltd | Manufacturing | 2022 |
| George Apostolache and SON Ltd | Transport & logistics | 2015 |
| George Colson Ltd | Professional & scientific | 2021 |
| George Cooper Swindon Limited | Arts & recreation | 2001 |
| George Plumbing and Maintenance Limited | Construction | 2026 |
| Georges Acogny Limited | Professional & scientific | 1991 |
| Geosho Technology Limited | Information & communication | 2016 |
| Geprony Traders Ltd | Information & communication | 2022 |
| Gerard Cash Services Ltd | Construction | 2012 |
| Gerfalcons Limited | Construction | 2023 |