| Gerrards Cross Golf Club,Limited | Arts & recreation | 1934 |
| GET (Environmental Health) Limited | Administrative & support | 1999 |
| Gil-Lec Limited | Wholesale & retail | 1985 |
| Glade (Marlow) Limited | Wholesale & retail | 1994 |
| Gladstone Road Properties Ltd | Real estate | 2003 |
| Glamo Limited | Health & social care | 2016 |
| Glassglobe Limited | Wholesale & retail | 1982 |
| Glebe Electrical Installations Limited | Construction | 1993 |
| Glenham Homes Limited | Construction | 2005 |
| Glentop Limited | Administrative & support | 1993 |
| Glenworth (Stone) Ltd | Construction | 2024 |
| Glenworth Construction Ltd | Construction | 2024 |
| Global Fire Alarm & Security Installations Ltd | Construction | 2015 |
| Global Ultimate Real Property Ltd | Real estate | 2024 |
| GLOBALSTORE360 Limited | Wholesale & retail | 2024 |
| Glodina International Limited | Professional & scientific | 2000 |
| Gloryy Homes Ltd | Real estate | 2023 |
| Goddard Bindery Group Limited | Manufacturing | 1993 |
| Grand Designs Ltd | Information & communication | 1997 |
| Grange Park (Bovingdon) Limited | Construction | 2002 |
| Greatgarden Limited | Administrative & support | 1999 |
| Green Door Designs Limited | Wholesale & retail | 2002 |
| Green Formula (UK) Ltd | Wholesale & retail | 2003 |
| Greenbrook Investment (Milton Keynes) Ltd | Construction | 2023 |
| Greencrest Solutions Limited | Mining & quarrying | 1999 |
| Grenadier Drainage Ltd | Water & waste | 2019 |
| Grindon NO.1 Ltd | Real estate | 2021 |
| Grover OUT of School Club Limited | Education | 2000 |
| Gwelyfenai Limited | Construction | 2024 |
| GX Home Improvements Limited | Construction | 2002 |
| H.M.T. Extensions Limited | Construction | 1987 |
| H.M.T. Property Co. Limited | Construction | 1987 |
| H.S. Floura (Osteopaths) Limited | Health & social care | 2002 |
| H.Y.G.H. Properties Limited | Real estate | 1969 |
| H1 Developments Limited | Construction | 2007 |
| Habibecom Ltd | Wholesale & retail | 2025 |
| Halecrest Developments Limited | Professional & scientific | 1985 |
| Halstan Holdings Limited | Administrative & support | 2003 |
| Hampden Buildings Limited | Real estate | 1925 |
| Hampden Homes Limited | Professional & scientific | 1992 |
| Hampden Legal PLC | Administrative & support | 1986 |
| Hand and Flowers Limited | Hospitality | 2005 |
| Hanson Bodyshop Limited | Wholesale & retail | 2004 |
| Haringtons Properties Limited | Real estate | 2004 |
| Harmony Beauty Therapy Limited | Other services | 2007 |
| Harry West Investments Limited | Real estate | 1960 |
| Hatton Court (Residents Association) Limited | Households | 1996 |
| Haynes-Shariff Business Consultants Limited | Professional & scientific | 2004 |
| Healthright Limited | Wholesale & retail | 2004 |
| Heath Carpentry Limited | Construction | 2012 |
| Hedges Farming Partners | | 1997 |
| Heiko Hoeft Tischlerei & Transporte Limited | Manufacturing | 2005 |
| Helium END Limited | Information & communication | 2014 |
| Hernlane Limited | Information & communication | 1987 |
| Hifi Cinema Limited | Wholesale & retail | 1993 |
| High Line Designs Limited | Manufacturing | 1998 |
| High Wycombe Bowling Green Co.,Limited(The) | Administrative & support | 1916 |
| Hillbrow Limited | Professional & scientific | 1998 |
| Hillier & Sons Limited | Real estate | 1994 |
| Hing's Fish & Chips Limited | Hospitality | 2002 |
| HLC Electrical Services Limited | Construction | 2005 |
| Holdfords of Iver Limited | Other services | 1991 |
| Homekeep Residents Co. Limited | Households | 1989 |
| Hopton Marriott Hillier Limited | Real estate | 1994 |
| Hoverpledge Limited | | 1987 |
| Howlands (Furniture) Limited | Professional & scientific | 1969 |
| Hugh Brune Limited | Information & communication | 1998 |
| Hull Mechanical Services Limited | Construction | 1990 |
| Hwadud Limited | Real estate | 2020 |
| Hydac Limited | Professional & scientific | 1991 |
| Hydac Technology Limited | Manufacturing | 1976 |
| I3 Global Design Limited | Professional & scientific | 1999 |
| Iboof Ltd | Other services | 2022 |
| Ideal Personnel & Recruitment Solutions Limited | Administrative & support | 2006 |
| Ignis Vitae Limited | Professional & scientific | 2000 |
| Ijazul Star Ltd | Hospitality | 2022 |
| Impetus Solutions Limited | Information & communication | 1996 |
| Imre Limited | Information & communication | 2004 |
| Incisive Letterwork Limited | Arts & recreation | 2003 |
| Infeco Ltd | Manufacturing | 2004 |
| Infinite Solutionzuk Limited | Professional & scientific | 2007 |
| Information Retrieval Consultants (Europe, Middle East, Africa) Limited | Professional & scientific | 1994 |
| Inline Moves Limited | Information & communication | 1982 |
| Innovative Software Development Limited | Information & communication | 1999 |
| Integrated Digital Solutions Limited | Wholesale & retail | 2019 |
| Integritas Consulting Ltd | Professional & scientific | 2002 |
| Inter City Trains Ltd. | Transport & logistics | 1999 |
| Intercan Group Limited | Manufacturing | 2001 |
| Interface-Tm Limited | Professional & scientific | 2003 |
| International Winwin Limited | Wholesale & retail | 2026 |
| Inukshuk Properties Limited | Real estate | 2019 |
| IP Voice Limited | Information & communication | 2020 |
| Irmak Cafe Ltd | Hospitality | 2023 |
| Ison Moulding Limited | Manufacturing | 2008 |
| IT Data and Security Limited | Information & communication | 2020 |
| IT Europa Media & Intelligence Limited | Information & communication | 2007 |
| IT Leaders Limited | Administrative & support | 2005 |
| IT Support Line Limited | Extraterritorial | 2006 |
| Itillion Limited | Information & communication | 2006 |
| Iver Recycling Limited | Water & waste | 2001 |