| Fenland Sustainable Futures CIC | Education | 2026 |
| Fenland Swim Academy Ltd | Arts & recreation | 2025 |
| Fenland Waste Management Ltd | Water & waste | 2024 |
| Fenland Youth Work Network CIC | Education | 2025 |
| Fenn Direct Limited | Administrative & support | 2005 |
| Fentec Engineering Limited | Professional & scientific | 2017 |
| FFF TOM Cave Limited | Arts & recreation | 2025 |
| FFN Mobile Services Limited | Health & social care | 2020 |
| Fields END Lodges Limited | Hospitality | 2021 |
| Fine Catering (March) Limited | Hospitality | 2010 |
| Finix Payment Ltd | Financial services | 2025 |
| Fink Energy Limited | Professional & scientific | 2023 |
| Fink Projection Plastering Limited | Construction | 2002 |
| Fiona Gray Creative Limited | Professional & scientific | 2016 |
| First Turn Media Limited | Professional & scientific | 2024 |
| Fishers Motor Group Ltd | Wholesale & retail | 2025 |
| Fishers of March Limited | Wholesale & retail | 2022 |
| FJS Manea Ltd | Construction | 2025 |
| FJS Manea Mains Limited | Construction | 2018 |
| FJS Services EOT Limited | Financial services | 2026 |
| Flaggrass Developments Limited | Households | 2023 |
| Flame Safety Ltd | Public administration | 2021 |
| Flames BBQ Ltd | Hospitality | 2019 |
| Flash Products UK Ltd | Manufacturing | 2023 |
| Fleetwood Technical Limited | Construction | 2025 |
| Flower Digital Ltd | Professional & scientific | 2025 |
| Flowers Bouquets Ltd | Wholesale & retail | 2022 |
| Flushing Success Ltd | Extraterritorial | 2025 |
| Flutterbies Childcare LLP | | 2014 |
| Football Epics Ltd | Manufacturing | 2023 |
| Force Construction Management Ltd | Construction | 2018 |
| Forecast Media Ltd | Professional & scientific | 2020 |
| Fork 'N' Knife Ltd | Hospitality | 2025 |
| Four Seasons March Ltd | Hospitality | 2025 |
| FPS RC Media Limited | Wholesale & retail | 2024 |
| Frederick Drive Limited | Real estate | 2024 |
| Freedom Motor Cycles Limited | Wholesale & retail | 2003 |
| Fresh Expressions Limited | Other services | 1998 |
| Fresh Path Solutions Ltd | Professional & scientific | 2025 |
| Friends for Needs Limited | Health & social care | 2018 |
| Fruit Technical Services & Support Limited | Wholesale & retail | 2017 |
| FRW (UK) Ltd | Construction | 2007 |
| Full Property Maintenance Ltd | Construction | 2025 |
| FUN Family Times Ltd | Information & communication | 2026 |
| G & a Mortgages Ltd | Financial services | 2017 |
| G & C a Lombardo Ltd | Wholesale & retail | 2015 |
| G & D Hair Studio Ltd | Other services | 2025 |
| G Woolmore Electrical Ltd | Construction | 2025 |
| G.E. & G.E. Fisher Limited | Agriculture & fishing | 1979 |
| GAC Group Ltd | Administrative & support | 2007 |
| Gadsby Developments Ltd | Real estate | 2026 |
| Galmart Logistics Ltd | Transport & logistics | 2020 |
| GAS Tech Utilities Ltd | Professional & scientific | 2017 |
| Gauchia Investments Limited | Wholesale & retail | 2025 |
| GB12 Limited | Administrative & support | 2020 |
| GBH Installations Ltd | Construction | 2022 |
| GBS Health and Safety Services Ltd | Professional & scientific | 2014 |
| GC Places Limited | Real estate | 2026 |
| Geles & F Construction Ltd | Construction | 2026 |
| Gemdome Limited | Construction | 1984 |
| GET Wrapped Kitchen Ltd | Hospitality | 2024 |
| Giddy Photo Booths Limited | Arts & recreation | 2016 |
| Gigabit Data Services Ltd | Information & communication | 2014 |
| GJS CONSTRUCT1ON Ltd | Construction | 2025 |
| GKL Estates Ltd | Real estate | 2025 |
| Glam Eats Ltd | Hospitality | 2022 |
| Glennance Ltd | Real estate | 2025 |
| Global Tree Solutions Ltd | Administrative & support | 2002 |
| Go 2 Infrastructure Solutions Limited | Financial services | 2022 |
| GO2 March Ltd | Real estate | 2026 |
| Goakes Building Ltd | Construction | 2023 |
| Goakessafety Limited | Professional & scientific | 2016 |
| Goddens Flooring & Home Interiors Ltd | Other services | 2012 |
| Gold Star Investment Group Ltd | Construction | 2023 |
| Gold Star Metal Traders Ltd | Water & waste | 2011 |
| Golden Raven Properties Ltd | Real estate | 2025 |
| Goldstar Consultancy Services Ltd | Extraterritorial | 2017 |
| Goldstar Demolition Services Ltd | Construction | 2017 |
| Good-Looking Wood Ltd | Construction | 2010 |
| Goodwin Kerb Layers Limited | Construction | 2013 |
| Goodwin Site Solutions Ltd | Construction | 2026 |
| Goude Estates Limited | Real estate | 2022 |
| GPM Services (UK) Limited | Wholesale & retail | 2014 |
| Grand Sweety Ltd | Other services | 2021 |
| Grandford Homes Limited | Construction | 2021 |
| Grass Pro Limited | Administrative & support | 2010 |
| GRE Services Ltd | Transport & logistics | 2025 |
| Greenbridge Care Ltd | Other services | 2019 |
| Greensmart Renewables Ltd | Other services | 2021 |
| Greenvale AP Limited | Agriculture & fishing | 1996 |
| Greenvale Holdings Limited | Agriculture & fishing | 2002 |
| Greystone Project Ltd | Construction | 2026 |
| Grounds Roastery Limited | Wholesale & retail | 2022 |
| GSC Partnership Ltd | Real estate | 2014 |
| Gsmt Holdings Limited | Financial services | 2019 |
| Gsmt Ltd | Wholesale & retail | 2020 |
| Gsmt Services Ltd | Extraterritorial | 2020 |
| Guild House Lease Co Limited | Real estate | 2024 |
| GUY James Limited | Construction | 2018 |
| H&S Carpet and Flooring Ltd | Wholesale & retail | 2023 |