| Freeheart Ltd | Wholesale & retail | 2020 |
| Freman College | Education | 2011 |
| Fremen Capital LP | | 2025 |
| Frog Hollow Estates Ltd | Real estate | 2012 |
| Frontline Facilities Ltd | Administrative & support | 2023 |
| FUR Q Accessories Ltd | Manufacturing | 2026 |
| Furneo Limited | Wholesale & retail | 2018 |
| Fusight Technology Limited | Information & communication | 1995 |
| G Brand Electrical Limited | Construction | 2022 |
| G&H Contracting Limited | Construction | 2019 |
| G&M Wilson Consultants Limited | Administrative & support | 2008 |
| G.S.T Electrical Ltd | Construction | 2025 |
| Gardenrama Company Limited | Administrative & support | 2021 |
| Gareth White Integration Services Ltd | Construction | 2014 |
| Gatehouse Mews Residents Association Limited | Households | 2000 |
| GB Equestrian Limited | Agriculture & fishing | 2025 |
| GC Roofing & Leadwork Ltd | Construction | 2022 |
| Geebee Events Ltd | Administrative & support | 2014 |
| Gems Promotions Ltd | Arts & recreation | 2023 |
| GEO Property Group Ltd | Real estate | 2023 |
| George Horner Hair Limited | Other services | 2026 |
| Gesko Limited | Information & communication | 2024 |
| Gibberish Limited | Manufacturing | 2003 |
| Gibson Waste Management Group Limited | Water & waste | 2025 |
| Gillers Antiques Ltd | Wholesale & retail | 2020 |
| Gilpin House Associates Ltd | Other services | 2018 |
| Glen Moore Limited | Transport & logistics | 2003 |
| GMF Joinery Design Limited | Professional & scientific | 2021 |
| Gokturk Ltd | Hospitality | 2019 |
| Golden Harvest House Ltd | Real estate | 2026 |
| Good Manors Limited | Professional & scientific | 1991 |
| Graphic Strategy Ltd | Professional & scientific | 2008 |
| Graypearl Limited | Real estate | 2021 |
| Green Chilli Buntingford Limited | Hospitality | 2026 |
| Green Dove Holdco Limited | Financial services | 2021 |
| Green Light Property Solutions Ltd | Real estate | 2019 |
| Green Property Growth Ltd | Extraterritorial | 2021 |
| Greenbase Landscaping & Driveways Ltd | Administrative & support | 2024 |
| Griffin International Transport Limited | Information & communication | 1991 |
| Group a Heatherbell Gardens Management Company Limited | Households | 2019 |
| Groves Consultancy Ltd | Construction | 2024 |
| GT Modular Contracts Limited | Administrative & support | 2017 |
| Gtbr Holdings Limited | Financial services | 2026 |
| Guardian Credit Ltd | Professional & scientific | 2004 |
| GX Golf Ltd | Wholesale & retail | 2020 |
| Haan Aromas Ltd | Wholesale & retail | 2020 |
| Hadar Consulting Ltd | Information & communication | 2025 |
| Hadham Securities Limited | Administrative & support | 2006 |
| Hall Barns (Furneaux Pelham) Management Co. Limited | Administrative & support | 1998 |
| Hall Cottages Management Company Limited | Households | 2007 |
| Handy GUY Services Ltd | Administrative & support | 2016 |
| Hansen LEE Consulting Ltd | Administrative & support | 2002 |
| HAP Solutions Limited | Administrative & support | 2020 |
| Harman Construction Limited | Construction | 2009 |
| Hastie Recruitment Ltd | Administrative & support | 2017 |
| HB78 Financial Ltd | Professional & scientific | 2026 |
| HDL Core Ltd | Professional & scientific | 2023 |
| Hedge Holdings Ltd | Real estate | 2019 |
| Hendrix Holdings Ltd | Hospitality | 2021 |
| Hertford Cake Co Ltd | Manufacturing | 2022 |
| Hertford Drylining Limited | Construction | 2017 |
| Hertfordshire Machinery Sales Ltd | Wholesale & retail | 2018 |
| Herts and Essex Cleaning Ltd | Administrative & support | 2025 |
| Herts Building Services Limited | Construction | 2019 |
| High Hedley Biogas Limited | Energy | 2007 |
| Hillcroft Media Productions Ltd | Wholesale & retail | 2021 |
| Hired IT Ltd | Administrative & support | 2025 |
| Historic Commercial Vehicle Society(The) | Other services | 1976 |
| Hixham Farms Limited | Agriculture & fishing | 1997 |
| Hobo Designs Limited | Manufacturing | 1994 |
| Home & Away Surveillance Limited | Other services | 1996 |
| Home Build Network Limited | Real estate | 2012 |
| Hoop House Estates Ltd | Real estate | 2016 |
| Hope and Love Limited | Wholesale & retail | 2013 |
| Hope and MAY Limited | Professional & scientific | 2014 |
| House of Dominus Ltd | Professional & scientific | 2025 |
| Hoveclose Limited | Professional & scientific | 1989 |
| HOW Farms Properties Limited | Real estate | 2025 |
| Hume Property Management Limited | Real estate | 2019 |
| Hummerston Engineering Ltd | Construction | 2023 |
| Hutch&Son Plumbing & Heating Limited | Construction | 2013 |
| HX2 Group Ltd | Construction | 2023 |
| Hytek Flat Roofing Ltd | Construction | 2019 |
| I&E Electrical Services Ltd | Manufacturing | 2021 |
| IAN Bray Plumbing & Heating Limited | Construction | 2003 |
| Imagine Financial Services Ltd | Professional & scientific | 2024 |
| Imago Photography Ltd | Professional & scientific | 2022 |
| IN Electronics Ltd | Construction | 2000 |
| Infinite Tech Digital Ltd | Wholesale & retail | 2023 |
| Ingelow Road NO 89 Limited | Households | 2023 |
| Interact Publishing Limited | Information & communication | 2002 |
| It's Just William Limited | Wholesale & retail | 2020 |
| IW Property Management Limited | Real estate | 2022 |
| J Walker & Co Ltd | Administrative & support | 2026 |
| J.K.M. Scaffolding Limited | Construction | 2001 |
| JAC Cane Accounting Limited | Professional & scientific | 2011 |
| Jack Berry Plant & Equipment Services Ltd | Professional & scientific | 2013 |
| Jack Poulton and Sons Limited | Transport & logistics | 1978 |
| James Woodhouse Communications Ltd | Professional & scientific | 2018 |
| Jameson Press Limited | Manufacturing | 2015 |