| G Howitt (Farrier) Limited | Other services | 2011 |
| G Lidyard Limited | Construction | 2014 |
| G M Maki Limited | Real estate | 2015 |
| G N G Biddle Decorators Limited | Construction | 2010 |
| G N G Biddle Properties Ltd | Real estate | 2023 |
| G Nanny Ltd | Health & social care | 2023 |
| G Naprous Ltd | Arts & recreation | 2011 |
| G P Financial Management Limited | Professional & scientific | 2003 |
| G P G Secretaries Limited | Administrative & support | 2001 |
| G Power Systems Ltd | Construction | 2019 |
| G READY2BUILD Construction Limited | Construction | 2025 |
| G Ryder & Co. Limited | Manufacturing | 1934 |
| G S Dhillon Limited | Transport & logistics | 2026 |
| G S H Ltd | Professional & scientific | 2019 |
| G Smart Energy Ltd | Construction | 2024 |
| G Squared Construction Limited | Construction | 2018 |
| G T Automation Limited | Construction | 2015 |
| G&B Build Solutions Ltd | Construction | 2026 |
| G&D Lounges Limited | Hospitality | 2017 |
| G&E MD Construction Ltd | Construction | 2024 |
| G&Es Property Ltd | Real estate | 2021 |
| G&H Properties MK Ltd | Real estate | 2023 |
| G&M Fung Properties Limited | Real estate | 2024 |
| G-Force Employment Limited | Extraterritorial | 2017 |
| G-Force Holdco Ltd | Financial services | 2021 |
| G-Medical Healthcare Services Limited | Administrative & support | 2023 |
| G-Security Solutions Ltd | Administrative & support | 2024 |
| G-Team Holdings Limited | Financial services | 2025 |
| G-Tech Talent Limited | Administrative & support | 2026 |
| G. Holloway (ST Albans) Limited | Construction | 2006 |
| G. I. Locum Limited | Administrative & support | 2018 |
| G. Kerri Consultancy Ltd | Professional & scientific | 2009 |
| G. Sadowski Limited | Construction | 1991 |
| G.B Driving & Logistics Limited | Transport & logistics | 2018 |
| G.B. Couriers Limited | Transport & logistics | 1992 |
| G.M. Irons Limited | Health & social care | 2002 |
| G.M. Transline Ltd | Transport & logistics | 2018 |
| G.Rosser Heating Ltd | Construction | 2014 |
| G12 Advisory Ltd | Professional & scientific | 2020 |
| G2 SSL Properties Limited | Real estate | 2025 |
| G2C Ventures Limited | Professional & scientific | 2026 |
| G2T Benefits Limited | Administrative & support | 2022 |
| GA Mughal Properties Ltd | Real estate | 2026 |
| GA Wood Flooring Limited | Construction | 2010 |
| Gaacpro Limited | Transport & logistics | 2024 |
| Gaap Capital Ltd | Real estate | 2025 |
| Gaap Consultancy Ltd | Information & communication | 2018 |
| Gaasolutions Ltd | Professional & scientific | 2019 |
| Gabex Limited | Wholesale & retail | 2025 |
| Gabi Consultancy Limited | Health & social care | 2016 |
| Gablisa Ltd | Information & communication | 2025 |
| GABY13 Ltd | Wholesale & retail | 2023 |
| Gaci Consulting UK Limited | Professional & scientific | 2025 |
| Gacio UK Limited | Transport & logistics | 2003 |
| Gade Printing Engineers Limited | Manufacturing | 2004 |
| Gaere Ltd | Professional & scientific | 2016 |
| Gaeta Dental Laboratory Ltd | Health & social care | 2014 |
| Gaeta Guard Ltd | Health & social care | 2017 |
| Gagawa UK Ltd | Manufacturing | 2024 |
| Gaign Consults Limited | Health & social care | 2012 |
| Gaik Limited | Administrative & support | 2025 |
| Gail Emms Consultancy Limited | Other services | 2008 |
| Gaimley Consulting Ltd | Professional & scientific | 2018 |
| Gainflow Management Accounting Limited | Professional & scientific | 2005 |
| Gainreward Limited | Wholesale & retail | 1991 |
| Gainsborough F S Limited | Financial services | 2005 |
| Gainway Limited | Real estate | 1994 |
| Gairsay Ltd | Hospitality | 1986 |
| Gajji Limited | Health & social care | 2011 |
| GAK Enterprises Ltd | Information & communication | 2011 |
| Galaxy Car Detailing Room Ltd | Wholesale & retail | 2022 |
| Galaxy CARE24 Ltd | Health & social care | 2024 |
| Galaxy Children's Homes Ltd | Health & social care | 2025 |
| Galaxy Consult Ltd | Information & communication | 2012 |
| Galaxy Nails Bletchley Ltd | Other services | 2020 |
| Galber Bookkeeping Limited | Professional & scientific | 2002 |
| Gale and Phillipson Investment Services Ltd | Financial services | 2005 |
| Galex Elec Ltd | Construction | 2019 |
| Gallery IT Limited | Information & communication | 2002 |
| Gallery Print and Art Ltd | Wholesale & retail | 2017 |
| Galleyiq Limited | Information & communication | 2025 |
| Gallus Holdings Ltd | Professional & scientific | 2021 |
| Gallus Ventures Ltd | Professional & scientific | 2021 |
| Galtonbridge Limited | Real estate | 2004 |
| Galvin Contracts Limited | Construction | 2011 |
| Galvin Fire Investigations Ltd. | Administrative & support | 2011 |
| GAM Logistics Ltd | Transport & logistics | 2021 |
| Gama Residential Limited | Real estate | 2025 |
| Gamar Healthcare Limited | Health & social care | 2019 |
| Gamarte Ltd | Construction | 2026 |
| Gamdar Xpress Ltd | Transport & logistics | 2024 |
| Gameverge Ltd | Wholesale & retail | 2015 |
| Gamma Group Ltd | Administrative & support | 1992 |
| Gamprotect Ltd | Administrative & support | 2024 |
| Ganatra Group Ltd | Financial services | 2025 |
| Ganatra Investments Ltd | Real estate | 2010 |
| Ganges Takeaway Ltd | Hospitality | 2025 |
| Gansons Engineering UK Limited | Wholesale & retail | 2020 |
| GAO Consultancy Limited | Information & communication | 2017 |
| Gapuma (UK) Limited | Extraterritorial | 1999 |