| Glemag Enterprises Limited | Real estate | 2024 |
| Glemag Holding Company Limited | Real estate | 2024 |
| Glemag Ltd | Real estate | 2011 |
| Glencross Building Group Ltd | Water & waste | 2015 |
| Glencross Construction Ltd | Construction | 2025 |
| Glenda Stephenson Limited | Professional & scientific | 2024 |
| Glenfields Solutions Ltd | Administrative & support | 2022 |
| Glengary House Ltd | Real estate | 2020 |
| Global Address Limited | Manufacturing | 2001 |
| Global Investment (International) Public Limited Company | | 1994 |
| Global Property Ventures Limited | Real estate | 2016 |
| GLOBALSHINE28 Limited | Other services | 2018 |
| Globe Civil Engineering Limited | Construction | 1997 |
| Globe Group Holdings Ltd | Construction | 1982 |
| Globe Home Improvements Limited | Construction | 2004 |
| Globe Roofing Ltd | Administrative & support | 2017 |
| Globe Scaffolding (Cambridge) Limited | Construction | 2002 |
| Globe Scaffolding (Special Projects) Limited | Construction | 2021 |
| Globe Scaffolding Limited | Construction | 1970 |
| Globe Utilities Ltd | Construction | 2005 |
| Globe-Mind UK Ltd | Professional & scientific | 2025 |
| Gloposnet Ltd | Information & communication | 2014 |
| Glorias Day Nursery Limited | Health & social care | 2002 |
| Glorious Shenanigans Films Ltd | Information & communication | 2025 |
| Gloslet Holdings Limited | Financial services | 2024 |
| Gloslet Limited | Real estate | 2023 |
| Gloucester Court Management (Hatfield) Limited | Households | 2007 |
| Glow by KT Limited | Other services | 2022 |
| GM Surgical Limited | Health & social care | 2022 |
| Gmac Maintenance Limited | Construction | 2018 |
| Gmec Property Investments Ltd | Real estate | 2023 |
| GML Project Services Limited | Professional & scientific | 2023 |
| Gmpharma Limited | Administrative & support | 2016 |
| GNB Electrical Services Limited | Construction | 2025 |
| GNT Investments Ltd | Administrative & support | 2025 |
| Gntech Consultancy Ltd | Information & communication | 2017 |
| Go Fiit Nutrition Limited | Manufacturing | 2018 |
| Go for Business Limited | Other services | 2025 |
| Go Mechanical Ltd | Construction | 2023 |
| Goble Labouring Services Limited | Construction | 2013 |
| Godyrette Limited | Professional & scientific | 2017 |
| Gold Star Taxis (Stevenage) Ltd | Extraterritorial | 2014 |
| Goldcrest Property and Services Limited | Real estate | 2025 |
| Goldcup Communications Limited | Information & communication | 1992 |
| Golden Stores Ltd | Wholesale & retail | 2024 |
| Golden Touch NMS Limited | Other services | 2019 |
| Goldie Pets Party Bakery & Supply Ltd | Manufacturing | 2019 |
| Goldleaf Homecare Herts Ltd | Health & social care | 2013 |
| Golf Plug Link Ltd | Administrative & support | 2025 |
| Gonanny Ltd | Health & social care | 2025 |
| Good Beagle Complany Ltd | Households | 2025 |
| Gooddeedit Ltd | Administrative & support | 2025 |
| Goodes Court Property Management Company Limited | Households | 2015 |
| Goodstep UK Limited | Other services | 2020 |
| Goosey Events Limited | Arts & recreation | 2025 |
| Gorka Limited | Transport & logistics | 2013 |
| Gosmore Road (Hitchin) Management Company Limited | Real estate | 2020 |
| Gotec Trading Limited | Wholesale & retail | 1978 |
| Govender Limited | Health & social care | 2018 |
| Gower Limited | Administrative & support | 1986 |
| Gozonemoblie Ltd | Wholesale & retail | 2024 |
| GP Care NOW Limited | Health & social care | 2022 |
| GP Connect Solutions Ltd | Administrative & support | 2023 |
| Gpclient SPV Ltd | Construction | 2021 |
| GPM Farming Services Limited | Agriculture & fishing | 2007 |
| GPM Property Maintenance Limited | Construction | 2020 |
| GPT Special Project Management Limited | Administrative & support | 1994 |
| Grab Publishing Ltd | Information & communication | 2026 |
| Grab Records Ltd | Information & communication | 2023 |
| Grace 04 Limited | Professional & scientific | 2025 |
| Grace @ Work Ltd | Wholesale & retail | 2025 |
| Grace Davies Ltd | Information & communication | 2023 |
| Grace Healthcare Ltd | Health & social care | 2020 |
| Grace Psalms Limited | Health & social care | 2020 |
| Gracefull Cleaning Solutions Ltd | Administrative & support | 2026 |
| Grade a Technology Limited | Wholesale & retail | 2013 |
| GRADE1 Cost Management Limited | Professional & scientific | 2015 |
| Gradedcomicsuk Limited | Wholesale & retail | 2019 |
| Gradeware Ltd | Information & communication | 2023 |
| Grafem Healthcare Limited | Health & social care | 2021 |
| Grafty Ltd | Information & communication | 2023 |
| Graham Tilley Ltd | Information & communication | 2009 |
| Grahame Ball Ltd | Real estate | 2024 |
| Grainger Engineering Ltd | Professional & scientific | 2021 |
| Gramik Commercial Limited | Real estate | 2023 |
| Gramik Limited | Real estate | 2018 |
| Grand BOB Real Estate Ltd | Extraterritorial | 2024 |
| Grand Tour Golf Limited | Administrative & support | 2022 |
| Granville Road Management Company Limited | Households | 1986 |
| Grass Roots TV Ltd | Construction | 2025 |
| Graysons Insurance (Consultants) Limited | Financial services | 1960 |
| Grayswood Computers Limited | Information & communication | 1987 |
| Grease Busterz Ltd | Construction | 2023 |
| Great Ashby Community Centre Management Association | Arts & recreation | 2006 |
| Great Ashby Residents Association Limited | Households | 2004 |
| Great Eastern Close Management Company Limited | Households | 1995 |
| Great North Road Limited | Real estate | 2023 |
| Great Oak Lodge Ltd | Health & social care | 2022 |
| Greater London Facilities Management Limited | Other services | 2021 |
| Greater London Surveys Ltd | Water & waste | 2018 |