| Gatto Grasso Ltd | Administrative & support | 2011 |
| Gbek Services Limited | Construction | 2007 |
| Gbid UK Ltd | Professional & scientific | 2022 |
| Gcrn Ltd | Information & communication | 2023 |
| Gent Fire & Security Ltd | Manufacturing | 2013 |
| Gentle Dusk Ltd | Health & social care | 2020 |
| Geonat Property Investments Ltd | Real estate | 2025 |
| George Street Canteen Limited | Hospitality | 2015 |
| GET Before SET Ltd | Construction | 2017 |
| GET Stuffed Live Events Limited | Arts & recreation | 2011 |
| GI Developments Limited | Construction | 2009 |
| GIB Vend Ltd | Administrative & support | 2015 |
| Gift of Beauty Ltd | Wholesale & retail | 2024 |
| Gilden Group Ltd | Real estate | 2025 |
| Gillian Gaskin Limited | Information & communication | 2018 |
| Ginger Brad MAN Carpentry Ltd | Manufacturing | 2026 |
| Girls Football Coaching Ltd | Education | 2020 |
| GJ Control Systems Limited | Professional & scientific | 2019 |
| GJH Consulting Limited | Other services | 2023 |
| Gladiatorit Computer Professionals Ltd | Information & communication | 2001 |
| Glidewise Ltd | Manufacturing | 2022 |
| Globular Merchandise Limited | Wholesale & retail | 2024 |
| Glovell Limited | Wholesale & retail | 2024 |
| Glover Production Sound Ltd | Information & communication | 2023 |
| Glowbeauty Bucks Limited | Other services | 2025 |
| GMD Management Consultancy Ltd | Professional & scientific | 2024 |
| Godspeeds Smallholding Ltd | Agriculture & fishing | 2019 |
| Goldfield Projects Limited | Information & communication | 2020 |
| Goldsil Limited | Real estate | 2015 |
| Gomm Geospatial Ltd | Information & communication | 2019 |
| Goodwin Soundings Ltd | Professional & scientific | 2025 |
| Gorilla Vanilla Limited | Manufacturing | 2019 |
| GP Air Conditioning Limited | Energy | 2019 |
| GPQ Holdings Ltd | Financial services | 2023 |
| GPR Racing Ltd | Wholesale & retail | 2020 |
| GR & PR Properties Limited | Hospitality | 2020 |
| Graces Maltings Residents Limited | Households | 2003 |
| Graham Haynes Associates Limited | Professional & scientific | 2003 |
| Grange FM Ltd | Construction | 2023 |
| Grapheve Property Ltd | Construction | 2014 |
| Grass Scapes Ltd | Administrative & support | 2019 |
| Gratitude Sports Management Ltd | Administrative & support | 2021 |
| Grayrose Home Builders Ltd | Construction | 2026 |
| Great Farm Wilstone (Management) Limited | Households | 1997 |
| Green Checkers Ltd | Professional & scientific | 2025 |
| Green END Holdings Ltd | Real estate | 2018 |
| Green Risk Ltd | Administrative & support | 2021 |
| Greenfleets Finance Limited | Financial services | 2010 |
| Greenfleets Holdings Limited | Financial services | 2026 |
| Greenfleets Limited | Financial services | 2008 |
| Greenhill Developments Ltd | Construction | 2017 |
| Greenlight Hicks Limited | Financial services | 2017 |
| Greenrey Ltd | Wholesale & retail | 2019 |
| Griffin Healthcare Ltd | Health & social care | 2024 |
| Groovycart Limited | Information & communication | 2008 |
| Grove Farm Management (Ivinghoe) Limited | Households | 2005 |
| Grove Innovations Limited | Construction | 2015 |
| Grove Park Residential Development Limited | Construction | 2014 |
| Grvl Ltd | Manufacturing | 2024 |
| Grymsdyke Farm Limited | Extraterritorial | 2014 |
| GS2 Design Limited | Professional & scientific | 2004 |
| GTL Consulting Ltd | Information & communication | 2024 |
| Guide Around Limited | | 1980 |
| Guild of Screen & Performance Medicine CIC | Other services | 2026 |
| Gunter Design Associates Limited | Professional & scientific | 1999 |
| Gutterbugs Limited | Construction | 2022 |
| Guys 'N' Dolls (Aylesbury) Limited | Other services | 2016 |
| GWB Marketing Solutions Ltd | Administrative & support | 2020 |
| GX Pro Shop Ltd | Wholesale & retail | 2020 |
| H Guzel Properties Ltd | Real estate | 2026 |
| H V Winter-Brown Ltd | Hospitality | 2018 |
| H&A Digital LLP | | 2025 |
| H-Bro Learning Limited | Health & social care | 2021 |
| H. E. Stringer Flavours Limited | Manufacturing | 2009 |
| H. Payne and Sons (Metals) Limited | Real estate | 1961 |
| H.E. Stringer (Perfumery) Limited | Manufacturing | 1962 |
| H.E.S. Land & Construction Limited | Construction | 2018 |
| Haamarve Ltd | Information & communication | 2025 |
| Hafren Financial Insights Ltd | Professional & scientific | 2020 |
| Hair 42 Ltd | Other services | 2013 |
| Hair With Chelsey Limited | Other services | 2026 |
| Hakosuka Technology Limited | Manufacturing | 2021 |
| Hale Mary Media Ltd | Professional & scientific | 2024 |
| Hallifords Consultancy Services Limited | Professional & scientific | 2024 |
| Halopain Ltd | Construction | 2025 |
| Halton Properties Limited | Extraterritorial | 2008 |
| Hamilton IT Limited | Information & communication | 2024 |
| Hamilton Video Limited | Information & communication | 2010 |
| Hammertime Holdings Limited | Real estate | 2021 |
| Handleport Limited | Professional & scientific | 2013 |
| Handsie Consulting Limited | Professional & scientific | 2003 |
| Hanley Creative Ltd | Information & communication | 2022 |
| Hannah Samuels Personal Training and Massage Ltd | Other services | 2019 |
| Happily Ever Agile Limited | Information & communication | 2023 |
| Happy AS Larry LLP | | 2020 |
| Hardwood Hayes Limited | Manufacturing | 2023 |
| Harma Limited | Extraterritorial | 2003 |
| Harper App Ltd | Information & communication | 2026 |
| Harper Halo Limited | Professional & scientific | 2025 |
| Harwin Marketing Limited | Wholesale & retail | 1998 |