| Gulf Breezes Trading Limited | Wholesale & retail | 2025 |
| Gulf Bridge Trading Limited | Wholesale & retail | 2025 |
| Gulf Cars Ltd | Extraterritorial | 2019 |
| Gulf Catering Limited | Hospitality | 2025 |
| Gulf Gazlan Trading Limited | Wholesale & retail | 2025 |
| Gulf Media Limited | Information & communication | 2018 |
| Gulf Print Trading Limited | Wholesale & retail | 2025 |
| Gulf Treasure Trading Limited | Wholesale & retail | 2025 |
| Gulfsok Ltd | Wholesale & retail | 2025 |
| Guli Shots Ltd | Wholesale & retail | 2023 |
| Gulnaz Hameed Ltd | Wholesale & retail | 2025 |
| Gulraiz Ltd | Wholesale & retail | 2025 |
| Gulrez Khan Ltd | Wholesale & retail | 2025 |
| Gumaan Saleh Company Ltd | Manufacturing | 2024 |
| Gunel Consulting & Online Internet Services Ltd | Wholesale & retail | 2020 |
| Gunfire Films Limited | Information & communication | 2025 |
| Gunfort Management Limited | Households | 2017 |
| Gunner Garage Limited | Wholesale & retail | 2017 |
| Gunsing Holdings Ltd | Real estate | 2024 |
| Gunter Properties Ltd | Real estate | 2022 |
| GUO Electronics Ltd | Wholesale & retail | 2026 |
| GUO Luwang Limited | Financial services | 2021 |
| GUO Peng Yang Ltd | Wholesale & retail | 2024 |
| Guomai Trading Co., Ltd | Extraterritorial | 2021 |
| Guowei Commerce Limited | Manufacturing | 2021 |
| GUR PAY HO Ltd | Professional & scientific | 2025 |
| GUR Service Ltd | Construction | 2023 |
| Gurbir SINGH1 Ltd | Construction | 2025 |
| Guri Build Services Ltd | Construction | 2025 |
| Gurnam & Sons Limited | Wholesale & retail | 2014 |
| Gurpreet SINGH1 Ltd | Construction | 2020 |
| Gurraj SINGH1 Ltd | Construction | 2025 |
| Guru Consultancy Ltd | Information & communication | 1998 |
| Guru House Ltd | Construction | 2023 |
| Gurubox Limited | Information & communication | 2023 |
| Gurung Pharm Ltd | Wholesale & retail | 2022 |
| Gusta Group Ltd | Professional & scientific | 2024 |
| Gusto and Aplomb Limited | Professional & scientific | 2015 |
| GUT Instinct Foods Limited | Hospitality | 2018 |
| Gutbalance Gbmeals Ltd | Wholesale & retail | 2024 |
| Guthrie Residential Ltd | Real estate | 2023 |
| Gutta Official Ltd | Wholesale & retail | 2025 |
| Gutter Cleaning Cardiff Ltd | Administrative & support | 2022 |
| Guut Technologies (UK) Limited | Information & communication | 2024 |
| GUY Christian Limited | Other services | 2011 |
| GUY Forks Ltd | Other services | 2018 |
| GUY Hancock Associates Limited | Professional & scientific | 2011 |
| Guy's College Limited | Education | 2018 |
| Guzin Ltd | Wholesale & retail | 2022 |
| Guzzy Bear Entertainment Limited | Information & communication | 2015 |
| GV Camera Ltd | Information & communication | 2020 |
| GVI Group Limited | Wholesale & retail | 2022 |
| GW Irving Ltd | Real estate | 2024 |
| GW Training Associates Ltd | Professional & scientific | 2025 |
| Gwahoddiad I Gymru Ltd | Administrative & support | 2020 |
| Gwaimountain Company LLP | | 2025 |
| Gwalia Housing Ltd | Real estate | 2024 |
| Gwalia Investments Limited | Real estate | 1962 |
| Gwalia Stays Ltd | Real estate | 2025 |
| Gwas Independent Ambulance Service Ltd | Professional & scientific | 2016 |
| Gwasg Addysgol Drake CYF | Other services | 1991 |
| Gwbert Holdings Limited | Real estate | 2020 |
| Gweeks Ltd | Wholesale & retail | 2024 |
| Gwendoline House Management Limited | Households | 2021 |
| Gwennan Oakes Limited | Professional & scientific | 2025 |
| Gwennol Environmental Ltd | Professional & scientific | 2025 |
| Gwenpat Limited | Wholesale & retail | 2023 |
| Gwent Auto Locksmith Ltd | Wholesale & retail | 2026 |
| Gwent Building Supplies Limited | Wholesale & retail | 1984 |
| Gwent Hospitals Workmen's and Contributory Fund(The) | Financial services | 1954 |
| Gwestai CYF | Other services | 2019 |
| Gwesty Cymru CYF | Hospitality | 2005 |
| Gwestyaberystwyth Ltd | Hospitality | 2020 |
| Gwifrau Scriptio Limited | Arts & recreation | 2013 |
| Gwilk Engineering Services Limited | Extraterritorial | 2013 |
| Gwineas Ltd | Health & social care | 2013 |
| Gwinners Ltd | Professional & scientific | 2024 |
| Gwinnutt Holdings Ltd | Real estate | 2024 |
| GWL Service and Maintenance Limited | Professional & scientific | 2022 |
| Gwoho Shyu Ltd | Wholesale & retail | 2025 |
| GWP Construction Limited | Construction | 2019 |
| GWP UK Limited | Manufacturing | 2000 |
| Gwpp Ltd | Administrative & support | 2023 |
| Gwrando Limited | Administrative & support | 2025 |
| Gwybodaeth CYF | Professional & scientific | 2025 |
| Gwyddelwern Bess Limited | Energy | 2023 |
| Gwyliau Eisteddfod Genedlaethol Cymru CYF | Arts & recreation | 2004 |
| Gwyliwr Seren Ltd | Hospitality | 2013 |
| Gwyn Eiddior CYF | Professional & scientific | 2022 |
| Gwyn-Du Properties Ltd | Real estate | 2025 |
| Gwynant Crescent Management (Number 2) Company Limited | Real estate | 2000 |
| Gwynant Crescent Management Company Limited | Households | 2000 |
| GWYNT360 Limited | Construction | 2025 |
| Gwyther Beech Estates Limited | Construction | 2019 |
| Gwên Fawr CYF. | Health & social care | 2023 |
| GXC International Trading Ltd | Wholesale & retail | 2024 |
| GXD Elite Ltd | Wholesale & retail | 2025 |
| GY Emergency Plumber Limited | Construction | 2024 |
| GY Solutions Limited | Wholesale & retail | 2026 |
| Gydes Ltd | Information & communication | 2020 |