| Fendyke Farming Limited | Agriculture & fishing | 2012 |
| Fenfab Engineering Spalding Ltd | Manufacturing | 2010 |
| Fenflow Limited | Manufacturing | 2002 |
| Fengate Fencing Ltd | Construction | 2019 |
| Fengate Homes Ltd | Real estate | 2022 |
| Fengate Property Limited | Real estate | 2021 |
| Fenhouse Land Limited | Construction | 2013 |
| Fenland Active Group Ltd | Hospitality | 2019 |
| Fenland Aero Club (Licensing) Limited | Arts & recreation | 2001 |
| Fenland Aero Services Ltd | Wholesale & retail | 2026 |
| Fenland Carpets and Flooring Ltd | Wholesale & retail | 2014 |
| Fenland Carpets Bourne Ltd | Other services | 2017 |
| Fenland Dental Laboratory Ltd | Health & social care | 2019 |
| Fenland Drives and Patios Ltd | Administrative & support | 2023 |
| Fenland Flying School Limited | Arts & recreation | 2014 |
| Fenland FM Group Ltd | Construction | 2025 |
| Fenland Materials Handling Limited | Wholesale & retail | 1994 |
| Fenland Paving and Resin Ltd | Administrative & support | 2025 |
| Fenland Plants Ltd | Agriculture & fishing | 2020 |
| Fenland Produce Limited | Wholesale & retail | 2017 |
| Fenland Roofing Limited | Construction | 2017 |
| Fenland Tractors Limited | Wholesale & retail | 2006 |
| Fenland Trading Ltd | Construction | 2025 |
| Fenlet Ltd | Real estate | 2022 |
| Fenndale Care Limited | Health & social care | 2023 |
| Fenpharma Ltd | Wholesale & retail | 2023 |
| Fenscape Limited | Administrative & support | 2023 |
| Fentech Agri Ltd | Manufacturing | 2022 |
| Fentech Holdings Limited | Financial services | 2018 |
| Fentech Ltd. | Professional & scientific | 2014 |
| Fenwood Property Ltd | Financial services | 2020 |
| Feodor Robert&Son Transport Ltd | Transport & logistics | 2018 |
| Ferro Vant 1 Limited | Real estate | 2026 |
| Ferro Vant 2 Limited | Real estate | 2026 |
| Ferrofab Engineering Ltd | Manufacturing | 2019 |
| Ferromarin Ltd | Wholesale & retail | 2025 |
| Fesa (UK) Limited | Wholesale & retail | 1984 |
| Festival Live Limited | Arts & recreation | 2009 |
| FFF Jack Withers Limited | Arts & recreation | 2025 |
| FFF Will Moxon Limited | Arts & recreation | 2026 |
| FHM22 Ltd | Transport & logistics | 2022 |
| Fibretek Fabrications Limited | Manufacturing | 2022 |
| Fidelis Holdings Ltd | Financial services | 2020 |
| Fieldfare Leisure Ltd | Arts & recreation | 2023 |
| Fields Farm Nature Play & Therapy CIC | Health & social care | 2025 |
| Fifty Fifty Threads Limited | Wholesale & retail | 2025 |
| Filip Haulage Ltd | Transport & logistics | 2025 |
| Fill Good Aesthetics Ltd | Other services | 2023 |
| Filter & Bloom Ltd | Hospitality | 2025 |
| Fimicoco Limited | Wholesale & retail | 2013 |
| Final Electrical Installations Ltd | Construction | 2024 |
| Finavico Limited | Administrative & support | 2017 |
| Find Your Power Coaching Ltd | Other services | 2025 |
| Finsmart Business Insights Limited | Professional & scientific | 2026 |
| Fire Science UK Ltd | Financial services | 2022 |
| First Call Property Maintenance Limited | Construction | 2022 |
| First Choice Machinery Ltd | Wholesale & retail | 2021 |
| First Choice Roofing & Repairs Ltd | Construction | 2019 |
| First Choice Roofing and Gardening Ltd | Construction | 2026 |
| First Choice Roofing Newark Notts Ltd | Construction | 2022 |
| First Choice Tree Care and Landscapes (Norfolk) Ltd | Administrative & support | 2021 |
| First Drove Holdings Ltd | Financial services | 2024 |
| First Drove Ltd | Wholesale & retail | 2018 |
| First Drove Property Limited | Other services | 2025 |
| First Step Logistics Limited | Transport & logistics | 2015 |
| Firstwatch Guarding Ltd | Administrative & support | 2025 |
| Firth Produce Ltd | Agriculture & fishing | 2021 |
| Firth&Co Limited | Real estate | 2023 |
| Fish Shack at Rampart Ltd | Arts & recreation | 2026 |
| Fisher & Co Accountancy Limited | Professional & scientific | 2020 |
| Fishermans Drinks Limited | Hospitality | 2018 |
| Fishing Lake 59 Limited | Hospitality | 2024 |
| Fishing Lake 61 Limited | Hospitality | 2024 |
| Fiszer Ltd | Transport & logistics | 2024 |
| FIX My Truck Ltd | Wholesale & retail | 2021 |
| FJ Property's (Yorkshire) Ltd | Real estate | 2025 |
| FJ Roofing and Gutters Ltd | Construction | 2023 |
| Fjgardens Ltd | Administrative & support | 2024 |
| FL Mcdust Ltd | Wholesale & retail | 2022 |
| Flagman Transport Ltd | Transport & logistics | 2024 |
| Fleet Road Garage Ltd | Wholesale & retail | 2019 |
| Fletch Moto Ltd | Wholesale & retail | 2024 |
| Fleur Jasmine Clothing Limited | Wholesale & retail | 2019 |
| Flexi Temp Cover Ltd | Financial services | 2025 |
| FLF Dent Ltd | Health & social care | 2014 |
| Flisher Photography Limited | Professional & scientific | 2016 |
| FLO MAS Ltd | Transport & logistics | 2015 |
| FLO Spedition Ltd | Transport & logistics | 2024 |
| Floralinc Limited | Transport & logistics | 2019 |
| Florentin Limited | Transport & logistics | 2015 |
| FLORIN-RECOVERY4YOU Ltd | Transport & logistics | 2025 |
| Floripack UK Ltd | Administrative & support | 2018 |
| Flow Screed Floors Limited | Other services | 2015 |
| Flower Direct Limited | Wholesale & retail | 2019 |
| Fluxfire Games Limited | Information & communication | 2025 |
| Flyball Vision Ltd | Information & communication | 2026 |
| FM Holding Group Ltd | Financial services | 2021 |
| FM Painting Ltd | Construction | 2022 |
| Fmbnb Holdings Limited | Financial services | 2025 |
| Fmec (East Anglia) Limited | Manufacturing | 2018 |