| Fulcrum Software Limited | Information & communication | 1994 |
| Full Fit Flooring Ltd | Construction | 2021 |
| Funclass Limited | Education | 2023 |
| Fusion Games Limited | Extraterritorial | 2005 |
| Fusione Consulting Ltd | Professional & scientific | 2022 |
| Futura Libertas Ltd. | Wholesale & retail | 2014 |
| Futurefuels (Africa) Limited | Transport & logistics | 2024 |
| Futurity Media Limited | Information & communication | 2002 |
| FYJ Ltd | Construction | 2026 |
| Fyreflight Games Ltd | Information & communication | 2024 |
| G & K Manson Holdings Limited | Financial services | 2015 |
| G Grogan Plumbing & Heating Limited | Construction | 2010 |
| G J Contractors Ltd | Construction | 2014 |
| G J Storey Ltd | Construction | 2023 |
| G Rees Dental Surgery Limited | Extraterritorial | 2010 |
| G S L Homestyle Properties Limited | Real estate | 2014 |
| G S Plumbing & Heating Solutions Limited | Construction | 2016 |
| G-Ten Limited | Wholesale & retail | 2024 |
| G. Kiziridis Foot & Ankle Essex Limited | Health & social care | 2021 |
| G.Gregory & J.Banham Properties Ltd | Real estate | 2020 |
| G.W.Martin & Co.Limited | Manufacturing | 1961 |
| G2 Associates Ltd | Professional & scientific | 2006 |
| Gag-Afi Ltd | Other services | 2024 |
| Gaglani & Co. Ltd | Professional & scientific | 2003 |
| Gair GAS Limited | Construction | 2002 |
| GAJ Builders Limited | Construction | 2009 |
| Galecroft Solutions Limited | Professional & scientific | 2002 |
| Gallant Motors Limited | Wholesale & retail | 2016 |
| Gambit Publications Limited | Information & communication | 1997 |
| GAP Creative Limited | Professional & scientific | 2016 |
| Garland Powersports Ltd | Wholesale & retail | 2023 |
| Garrison Trading Limited | Financial services | 2022 |
| GAS Adept Ltd | Construction | 2013 |
| GAS Alight Ltd | Administrative & support | 2014 |
| GAS Rated Ltd | Construction | 2014 |
| Gaspoint South Limited | Construction | 2006 |
| Gateway Contract Flooring Limited | Professional & scientific | 2008 |
| Gateway Interiors Limited | Extraterritorial | 2008 |
| Gather & Nest Ltd | Administrative & support | 2017 |
| Gaucho Transports Ltd | Transport & logistics | 2024 |
| Gauntlet Management Company Limited | Households | 1990 |
| Gavweld Limited | Manufacturing | 2016 |
| GB Accounting & Business Services Ltd | Professional & scientific | 2013 |
| GB Fencing and Landscaping Ltd | Administrative & support | 2018 |
| GB Security Consultancy Ltd | Professional & scientific | 2013 |
| GBZ Wellness UK Ltd | Wholesale & retail | 2024 |
| GC Eastleigh Barber Ltd | Other services | 2025 |
| GC RGN Limited | Health & social care | 2022 |
| GCP Consortium Ltd | Financial services | 2018 |
| GCS Wessex Ltd | Other services | 2016 |
| GD Technical Solutions Ltd | Construction | 2023 |
| GDB Roofing Ltd | Construction | 2019 |
| GDM Bathrooms Limited | Administrative & support | 2017 |
| Geartronix (UK) Limited | Wholesale & retail | 2024 |
| Gecko Contractor Holdings Ltd | Financial services | 2023 |
| Gecko Metal Works Ltd | Manufacturing | 2014 |
| Gecko Renewable Energy Ltd | Construction | 2023 |
| Gee's Holdings Limited | Professional & scientific | 2025 |
| Geek Unique Ltd | Professional & scientific | 2017 |
| Gelato Dreams Limited | Hospitality | 2025 |
| Gemcare Southampton Ltd | Health & social care | 2020 |
| Gemini Planning Services Limited | Professional & scientific | 2019 |
| General Electrical Services Limited | Construction | 2022 |
| General Mechanic Ltd | Wholesale & retail | 2024 |
| Genie Scaffolding Ltd | Construction | 2018 |
| Genio Capital Limited | Financial services | 2019 |
| Gentrac Systems Limited | Wholesale & retail | 1991 |
| Gentry Barbershop Ltd | Other services | 2026 |
| Geocerta Ltd | Information & communication | 2024 |
| Gerstrom Property Services Ltd | Real estate | 2012 |
| GES Digital Ltd | Construction | 2014 |
| GET UP and Co Limited | Education | 2020 |
| Getpoke’D Ltd | Wholesale & retail | 2026 |
| Ghooby Ltd | Wholesale & retail | 2018 |
| Giant Store Southampton Limited | Wholesale & retail | 2016 |
| Gibbs & Andrews Ltd | Health & social care | 2023 |
| Gibunco (UK) Limited | Administrative & support | 1997 |
| Gigant Holdings Limited | Financial services | 2024 |
| Gigant Products for Industry Ltd | Wholesale & retail | 2012 |
| Gillies Limited | Administrative & support | 2013 |
| GJL Installations Ltd | Construction | 2011 |
| Gjse Limited | Administrative & support | 2020 |
| Gjsjpartners Ltd | Wholesale & retail | 2025 |
| GK Driver Recruitment Ltd | Administrative & support | 2022 |
| Glam-R-House Ltd | Administrative & support | 2021 |
| Glanville Court RTM Company Limited | Households | 2010 |
| Glass and Window Solutions Limited | Construction | 2026 |
| Glass NIB Ltd | Professional & scientific | 2011 |
| Glass Partition Services (Hampshire) Limited | Construction | 2023 |
| Glassjacks Ltd | Manufacturing | 2011 |
| Glee Cocktails Ltd | Wholesale & retail | 2021 |
| Glen Island House Management Limited | Households | 2020 |
| GLG Refrigeration Limited | Administrative & support | 2006 |
| Glidepath ATM Ltd | Professional & scientific | 2022 |
| Gloace Limited | Information & communication | 2012 |
| Global Ceramic Tiling Holdings Limited | Financial services | 2022 |
| Global Ceramic Tiling Limited | Construction | 2000 |
| Global Ceramic Tiling Trustees Limited | Professional & scientific | 2022 |
| Global Content Protection Ltd | Information & communication | 2013 |
| Global Graphics Limited | Wholesale & retail | 1992 |