| Fossil (UK) Limited | Wholesale & retail | 1995 |
| Foster Construction Services Ltd | Construction | 2007 |
| Fosters Inn Limited | Hospitality | 2025 |
| Foto Thru the Looking Glass Limited | Wholesale & retail | 2016 |
| Found and Foster Ltd | Professional & scientific | 2025 |
| Foundation Psychological Services Limited | Health & social care | 2005 |
| Foundations Health and Fitness Coaching Ltd | Other services | 2026 |
| Foundry Brickworks Limited | Construction | 2014 |
| Foundry Infrastructure Ltd | Information & communication | 2026 |
| Four Cardinal (UK) Limited | Construction | 2022 |
| Four H Autos Limited | Wholesale & retail | 2024 |
| Four Hold Limited | Real estate | 2021 |
| Four Islands General Limited | Other services | 2024 |
| Four Oaks Financial Planning Limited | Extraterritorial | 2007 |
| Four Oceans Investment Ltd | Wholesale & retail | 2019 |
| Four Pillars Group Limited | Financial services | 2026 |
| Four Pillars Property Ltd | Real estate | 2020 |
| Four Seasons Plumbing & Drainage Limited | Construction | 2017 |
| Fourball Ltd | Information & communication | 2026 |
| Fourppm Limited | Information & communication | 2008 |
| Fourteen Fit HQ Ltd | Arts & recreation | 2025 |
| Fourteen Lakes Limited | Hospitality | 2023 |
| Fourth ARR Ltd | Real estate | 2019 |
| Fourthzone Ltd | Information & communication | 2023 |
| Fourwinds Engineers Limited | Professional & scientific | 1978 |
| FOX Aero Design and Engineering Limited | Extraterritorial | 2009 |
| FOX at Barrington Limited | Hospitality | 2025 |
| FOX Burrow Consulting Limited | Professional & scientific | 2025 |
| FOX Covert Investment Company Limited | Financial services | 2022 |
| Foxberry Developments (Meppershall) Limited | Construction | 2019 |
| Foxberry Developments Limited | Construction | 2016 |
| Foxberry Investments Limited | Real estate | 2016 |
| Foxey Leys Management (Bicester) Limited | Households | 1994 |
| Foxglove Bidco Limited | Financial services | 2024 |
| Foxglove Holdco Limited | Financial services | 2024 |
| Foxglove Midco Limited | Financial services | 2024 |
| Foxpot Limited | Professional & scientific | 2023 |
| FP Animal Therapy Centre Ltd | Other services | 2022 |
| FP LUX Scurf Dyke Solar Limited | Energy | 2019 |
| Fpav Limited | Construction | 2022 |
| FPC Life Sciences Limited | Professional & scientific | 2024 |
| FPS Construction Management Ltd | Professional & scientific | 2009 |
| FR Enterprises Limited | Wholesale & retail | 2020 |
| Fracas Digital Limited | Professional & scientific | 2021 |
| FRACTION41 Limited | Information & communication | 2025 |
| Framequest Ltd | Professional & scientific | 2023 |
| Framovision Tidy Ltd | Administrative & support | 2018 |
| Frampton Fire Ltd | Public administration | 2021 |
| Franbury Ltd | Arts & recreation | 2019 |
| Frances Thornton Ltd | Other services | 2012 |
| Francesca Nicole Limited | Health & social care | 2014 |
| Francis & Stephens Start UP Solution Limited | Health & social care | 2015 |
| Francis Homes Limited | Households | 2023 |
| Francis Nicholls Limited | Construction | 2013 |
| Francis Rose Landscapes Limited | Administrative & support | 2017 |
| Francis the Handyman Limited | Construction | 2026 |
| Francisco E Silva Ltd | Hospitality | 2023 |
| Franco Sliced and Diced Limited | Hospitality | 2019 |
| Frangis Health Care Limited | Health & social care | 2023 |
| Frango MK Limited | Hospitality | 2026 |
| Frank Brown & SON Luton Limited | Manufacturing | 1966 |
| Frank Flair Tech Ltd | Information & communication | 2021 |
| Frank Mobile Solutions Ltd | Information & communication | 2022 |
| Frankeinstein Ltd | Manufacturing | 2021 |
| Frankform Marketing Ltd | Professional & scientific | 2013 |
| Frankie a Consultants Ltd | Professional & scientific | 2025 |
| Franklin Hammond HR Consulting Limited | Administrative & support | 2024 |
| Franklin Products Limited | Manufacturing | 1998 |
| Franklite Limited | Manufacturing | 1972 |
| Frankthebarber Ltd | Other services | 2025 |
| Franomo Limited | Professional & scientific | 2010 |
| Fransen Professional Limited | Wholesale & retail | 2008 |
| Fraoula Ltd | Hospitality | 2020 |
| Frasco Consulting Ltd | Professional & scientific | 2026 |
| Fratellis Master Caterers Limited | Hospitality | 2019 |
| Fratila Ltd | Health & social care | 2017 |
| Frazer Nash Communications & PR Limited | Administrative & support | 2018 |
| FRB Developments Limited | Real estate | 2016 |
| FRD Services Ltd | Professional & scientific | 2024 |
| Freckles Caribbean Limited | Hospitality | 2025 |
| Fred and Josh Limited | Transport & logistics | 2020 |
| Fred Roche Foundation Limited | Health & social care | 1996 |
| Fred the Tread Ltd | Extraterritorial | 2024 |
| Freddy & Sky Limited | Wholesale & retail | 2016 |
| Freddy Hirsch Group UK Limited | Manufacturing | 2020 |
| Fredies Roofing Limited | Construction | 2022 |
| Free Spirit Management Benefits Ltd | Professional & scientific | 2026 |
| Freedom House Ministry Ltd | Other services | 2016 |
| Freedom Services (MAG Foods) Ltd | Hospitality | 2025 |
| Freelance CRA Limited | Professional & scientific | 2015 |
| Freelancegeek Ltd | Information & communication | 2016 |
| Freeman Grabs Ltd | Construction | 2024 |
| Freeman House & Co. Limited | Arts & recreation | 2025 |
| Freemover Ltd | Other services | 2024 |
| Freepeople Limited | Information & communication | 2010 |
| Freestone Creative Trustees Limited | Other services | 2026 |
| Freeztech Limited | Manufacturing | 2011 |
| Freidman FM Limited | Administrative & support | 2007 |
| Freight-Tech Limited | Wholesale & retail | 2024 |
| Frelvyn Group Investments Ltd | Arts & recreation | 2020 |