| Genovea CLAN10 Limited | Health & social care | 2015 |
| Genrat Limited | Extraterritorial | 2023 |
| Gentech International Ltd | Information & communication | 2025 |
| Gentle Smile Limited | Health & social care | 2013 |
| GEO Miron Ltd | Construction | 2017 |
| GEO Property Investment Limited | Real estate | 2013 |
| GEO Technologies Limited | Professional & scientific | 1998 |
| Geognostics International Limited | Professional & scientific | 2016 |
| Geolabs Ltd | Professional & scientific | 1996 |
| Geomingle Ltd | Information & communication | 2015 |
| Geonova Solution 555 Ltd | Other services | 2024 |
| Geoprops Ltd | Real estate | 2018 |
| George Depledge & Co. | Wholesale & retail | 1921 |
| George Dilloway Ebbsfleet Limited | Financial services | 2025 |
| George Hugh Contractors Limited | Administrative & support | 2013 |
| George Langford Limited | Professional & scientific | 2024 |
| George MA Services Limited | Wholesale & retail | 2022 |
| George Martin Music Limited | Information & communication | 1969 |
| George the Builder Ltd | Construction | 2013 |
| George Theo London Ltd | Real estate | 2022 |
| George's Home Ltd | Health & social care | 2023 |
| Geoscape Ltd | Professional & scientific | 2014 |
| Geospring Progress Ltd | Wholesale & retail | 2018 |
| Geotechnical & Environmental Services Limited | Construction | 1997 |
| Gerald LEE Consulting Ltd | Information & communication | 2011 |
| GET Cosmetics Ltd | Wholesale & retail | 2020 |
| GET IT UP Scaffolding Ltd | Construction | 2023 |
| GET Supplied Ltd | Wholesale & retail | 2023 |
| Getdomus Limited | Administrative & support | 2023 |
| Getmynest Holdings Limited | Wholesale & retail | 2025 |
| Geziee Consulting Ltd | Information & communication | 2022 |
| GG Pro Ltd | Administrative & support | 2020 |
| GGM Commodities Ltd | Financial services | 2018 |
| GGM Construction Surveying Services Ltd | Professional & scientific | 2012 |
| Ghana United Watford C.I.C. | Education | 2023 |
| Ghanesh Properties Ltd | Real estate | 2021 |
| Ghermans Loyalty Ltd | Construction | 2024 |
| Ghero Construction Ltd | Construction | 2018 |
| Gheron Limited | Transport & logistics | 2016 |
| Ghkproperty Ltd | Real estate | 2025 |
| Ghost Fragrances Limited | Administrative & support | 2012 |
| Ghost Holdings Ltd | Real estate | 2021 |
| Ghstructures Limited | Construction | 2025 |
| GHT Project Management Ltd | Professional & scientific | 2019 |
| Gianina Ltd | Wholesale & retail | 2025 |
| Giant IT Consulting Limited | Information & communication | 2014 |
| Giant Otter Ltd | Professional & scientific | 2018 |
| Giant Pizza Watford Ltd | Hospitality | 2026 |
| Giarca Consulting Ltd | Professional & scientific | 2026 |
| Gibbor Psychology Ltd | Health & social care | 2023 |
| Gibson Global Publications Ltd | Health & social care | 2023 |
| Gideons Industries Ltd | Wholesale & retail | 2023 |
| Giffords (England) Limited | Other services | 2019 |
| Gigapixel Image Co Ltd | Professional & scientific | 2020 |
| Gigbox Gignation Ltd | Information & communication | 2020 |
| Giggles & Tots Ltd | Health & social care | 2025 |
| Gilardini Real Estate Ltd | Real estate | 2025 |
| Gilardini Realty Ltd | Real estate | 2012 |
| Gilbert AL & Sons Ltd | Hospitality | 2019 |
| Gilbert Motors Limited | Wholesale & retail | 1993 |
| Gilded Group Limited | Manufacturing | 2024 |
| Gilgo Limited | Arts & recreation | 2004 |
| Gill Global Trade Ltd | Wholesale & retail | 2024 |
| Gill Health Care Services Limited | Health & social care | 2016 |
| Gill London Enterprises Ltd | Real estate | 2012 |
| GILL-4-INVESTMENT Ltd | Real estate | 2019 |
| Gillani Construction Ltd | Construction | 2024 |
| Gillani Estate Ltd | Real estate | 2023 |
| Gilmartin Family Company Limited | Construction | 2012 |
| Gilmartins Building Services Limited | Construction | 2020 |
| Gilmartins Development Limited | Construction | 2013 |
| Gilmartins Family Investment Company Limited | Real estate | 2025 |
| Gilmartins Properties Limited | Real estate | 2018 |
| Gilmartins Telford House Limited | Real estate | 2020 |
| Gimeco Limited | Administrative & support | 2019 |
| Gimme Ice Limited | Hospitality | 2009 |
| GIN Foundry Limited | Manufacturing | 2014 |
| Ginder Property Holdings Limited | Real estate | 2021 |
| Giquina Accountancy Limited | Professional & scientific | 2025 |
| Giquina Capital Limited | Financial services | 2025 |
| Giquina Management Holdings Ltd | Financial services | 2024 |
| Giquina Structured Asset SPV Limited | Financial services | 2025 |
| Giraffe PPM Ltd | Professional & scientific | 2022 |
| Girosol Entertainment Ltd | Arts & recreation | 2026 |
| Gitg Investments Ltd | Real estate | 2026 |
| Giving-Mind Lifestyle Foundation (GLF) | Health & social care | 2019 |
| Giza Design and Build Ltd | Construction | 2026 |
| GJA Properties Limited | Real estate | 2017 |
| Gjata Accounting Ltd | Professional & scientific | 2019 |
| GJC Games Group Ltd | Financial services | 2021 |
| GJC IP Holdings Limited | Information & communication | 2016 |
| GK Fire Limited | Public administration | 2023 |
| GK Signalling Ltd | Manufacturing | 2025 |
| Gkjh Consulting Limited | Professional & scientific | 2025 |
| Gkmr Ltd | Transport & logistics | 2022 |
| GKT Wines Ltd | Wholesale & retail | 2015 |
| GL Commerce Ltd | Extraterritorial | 2024 |
| Gladstone Court (Estate Management) Limited | Households | 1963 |
| Glamour Hair UK Ltd | Wholesale & retail | 2019 |
| Glante Software Limited | Information & communication | 2017 |