| Fenline Developments Ltd | Agriculture & fishing | 2025 |
| Fentex Limited | Manufacturing | 1998 |
| Fenton Manufacturing Limited | Manufacturing | 2009 |
| Fermat Consulting Limited | Extraterritorial | 2010 |
| Festival Equestrian Events Limited | Arts & recreation | 2021 |
| Fieldcraft Technologies UK Ltd | Agriculture & fishing | 2024 |
| Fierce Angel Records Limited | Arts & recreation | 2005 |
| Find My Van Finance Ltd | Administrative & support | 2022 |
| Fine Living Rentals Ltd | Real estate | 2024 |
| Finish Pro Limited | Construction | 2015 |
| Finn BOB Holdings Ltd | Real estate | 2024 |
| Finn Stanley Investments Limited | Financial services | 2020 |
| Fire & Safety Solutions Limited | Professional & scientific | 2003 |
| Fire Clear Ltd | Professional & scientific | 2019 |
| Fire Risk Management Associates Limited | Professional & scientific | 2013 |
| Firesnuff Holdings Limited | Financial services | 2025 |
| First AID Training Services Ltd | Education | 2007 |
| First Choice Landscaping & Driveways Ltd | Administrative & support | 2026 |
| First Step Developments Limited | Real estate | 2021 |
| First Step Invest Limited | Administrative & support | 2019 |
| First Step Lettings Limited | Real estate | 2016 |
| First Step Partnership Limited | Real estate | 2017 |
| First Step Provenance Limited | Real estate | 2021 |
| First Step the Housing Partners Limited | Other services | 2010 |
| First Team Consultancy Ltd | Construction | 2017 |
| Fisheagle Investments Ltd | Transport & logistics | 2017 |
| Fisher Terrace Management Company Limited | Real estate | 2007 |
| Fishers of ST Neots Limited | Wholesale & retail | 2010 |
| Fitch Dawe Consulting Ltd | Professional & scientific | 2010 |
| Fitch Media Limited | Professional & scientific | 2009 |
| Fitness Rush Community CIC | Arts & recreation | 2022 |
| Fitness Rush Franchising Ltd | Extraterritorial | 2021 |
| Fitness Rush Ltd | Arts & recreation | 2020 |
| Fitness Rush Mobile Ltd | Arts & recreation | 2020 |
| Fitzpatrick Healthcare Ltd | Public administration | 2024 |
| Fitzroy Land and Property Limited | Construction | 2019 |
| Five Star Hunts Ltd | Hospitality | 2022 |
| Fivetara Spices Ltd | Hospitality | 2015 |
| Fixfitt Ltd | Construction | 2025 |
| FJC Construction Ltd | Construction | 2025 |
| Flabbergast Industries Ltd | Arts & recreation | 2012 |
| Flabbergast Laboratory Collective CIC | Arts & recreation | 2025 |
| Flanders Rose Limited | Real estate | 2025 |
| Flare PAY Ltd | Information & communication | 2022 |
| Flashmemo Ltd. | Wholesale & retail | 2007 |
| Flats 59 High Street (Warboys) Management Company Limited | Households | 1990 |
| Fleet Assist Interco Limited | Financial services | 2017 |
| Fleet Assist Limited | Administrative & support | 2003 |
| Fleet Assure Group Ltd | Professional & scientific | 2024 |
| Fleming Contracting Services Limited | Construction | 2015 |
| Flexerefrigeration Limited | Administrative & support | 2012 |
| Flexi Homecare Ltd | Administrative & support | 2024 |
| Flexible Wall Systems Limited | Construction | 2008 |
| Flight to Quality Limited | Professional & scientific | 2026 |
| Flint Burrell Limited | Hospitality | 2010 |
| FLK Agro UK Limited | Wholesale & retail | 2018 |
| Flood Protection Association | Administrative & support | 2016 |
| Floraela Ltd | Wholesale & retail | 2021 |
| Flovia Homes Ltd | Real estate | 2026 |
| Flowcultura Limited | Professional & scientific | 2015 |
| Flowent Limited | Construction | 2021 |
| Fluid Water Jetting Co Ltd | Manufacturing | 2021 |
| FNR Machinery Limited | Wholesale & retail | 2007 |
| FNR Properties Limited | Real estate | 2015 |
| Foframe of Huntingdon Limited | Financial services | 1975 |
| Foframe Properties Limited | Real estate | 1983 |
| Food and Agriculture Experts International Ltd | Manufacturing | 2023 |
| Food Cash and Carry Ltd | Wholesale & retail | 2026 |
| Foot Sure Podiatry Ltd | Health & social care | 2011 |
| FOP & Dandy Ltd | Professional & scientific | 2007 |
| Force Fresh Limited | Wholesale & retail | 1991 |
| Foremans GP Ltd | Real estate | 2024 |
| Foremasons Limited | Financial services | 2020 |
| Forensal Limited | Professional & scientific | 2011 |
| Forss Energy Storage Limited | Energy | 2022 |
| Forte Dance Academy Limited | Arts & recreation | 2016 |
| Fortec Technology UK Limited | Wholesale & retail | 2001 |
| Fortune Academic Services Ltd | Education | 2026 |
| Foster Horticulture Landscape Management Limited | Other services | 2003 |
| Foster Phelps (Alconbury) Limited | Arts & recreation | 2023 |
| Foster Phelps (Holdings) Limited | Arts & recreation | 2023 |
| Foster Phelps (Online) Limited | Arts & recreation | 2023 |
| Foster Phelps Limited | Arts & recreation | 2013 |
| Four PAW Racing Ltd | Wholesale & retail | 2019 |
| Fourlar Consulting Limited | Professional & scientific | 2025 |
| Fowler FOX & Co Limited | Administrative & support | 2012 |
| FOX Estimating & Surveying Ltd | Professional & scientific | 2020 |
| FOX Racing Developments Limited | Manufacturing | 2005 |
| Fraclaval Limited | Real estate | 2018 |
| Framework Build Ltd | Construction | 2022 |
| Franco Carpet Cleaning Limited | Administrative & support | 2025 |
| Franco Vending Machines Limited | Hospitality | 2026 |
| Frank Bros. Limited | Wholesale & retail | 2013 |
| Frank Turner Limited | Manufacturing | 2003 |
| Frank's Windscreens Ltd | Professional & scientific | 2023 |
| Franklins Flooring Limited | Wholesale & retail | 2003 |
| Fred Garner Limited | Agriculture & fishing | 1946 |
| Freddie Beauvoir Limited | Wholesale & retail | 2016 |
| Freebird Consultancy Services Ltd | Professional & scientific | 2025 |
| Freelance Financial Controller Limited | Professional & scientific | 2014 |