| Four A'J Ltd. | Professional & scientific | 2016 |
| Four Angel Care Ltd | Hospitality | 2018 |
| Four Bees Consultancy Services Limited | Professional & scientific | 2016 |
| Four Eight Holdings Limited | Real estate | 2018 |
| Four Elements Medical Services Ltd | Health & social care | 2019 |
| Four Five Studio Ltd | Information & communication | 2023 |
| Four Floors Ltd | Construction | 2025 |
| Four One One Management Limited | Real estate | 1988 |
| Four Seasons Nails Studio Ltd | Other services | 2022 |
| Four Shires Contracting Limited | Construction | 2010 |
| Four Sisters Property Development Ltd | Real estate | 2020 |
| Four Sisters Social Care Ltd | Health & social care | 2021 |
| Four Sisters Surveying Services Ltd | Professional & scientific | 2023 |
| Four Talent Ltd | Administrative & support | 2021 |
| Fourcee Investments Ltd | Real estate | 2024 |
| Fourdotzero Ltd | Information & communication | 2021 |
| Fourdotzero Software Ltd | Information & communication | 2023 |
| Fourtwocmd Limited | Information & communication | 2025 |
| Fourways Industrial Ltd | Construction | 2019 |
| Fowkes & SON Limited | Financial services | 2021 |
| FOX & Co Developments Ltd | Extraterritorial | 2021 |
| FOX & Co Groundworks & Developments Ltd | Construction | 2014 |
| FOX & Co Groundworks Ltd | Extraterritorial | 2021 |
| FOX & Co Plant Ltd | Construction | 2021 |
| FOX Bazaar Ltd | Wholesale & retail | 2025 |
| FOX Covert Ltd | Real estate | 2024 |
| FOX Covert Management Limited | Other services | 1996 |
| FOX Covert Property LLP | | 2022 |
| FOX Electrical Services Limited | Construction | 2020 |
| FOX Flare Media Ltd | Professional & scientific | 2024 |
| FOX Industry Estates Ltd | Construction | 2025 |
| FOX Meadows (Thorpe Astley) Management Company Limited | Real estate | 2005 |
| FOX Red Outbound Ltd | Information & communication | 2024 |
| Fox's Pallets Limited | Administrative & support | 2001 |
| Foxs Holdings Co. (UK) Limited | Administrative & support | 2024 |
| Foxtales UK Limited | Health & social care | 2013 |
| FP Insieme Limited | Professional & scientific | 2016 |
| FP Locations Ltd | Information & communication | 2024 |
| Fpabl Limited | Financial services | 2016 |
| Fpiuk Alumni | Other services | 2018 |
| FR Contracting Solutions Ltd | Agriculture & fishing | 2024 |
| Fractio Limited | Professional & scientific | 2026 |
| Fractional CFO DOT Ltd | Administrative & support | 2019 |
| Frame 25 Limited | Administrative & support | 2009 |
| Frame 25 Recruitment Limited | Extraterritorial | 2019 |
| Framemaker Online Ltd | Wholesale & retail | 2021 |
| Framework Support Services Limited | Administrative & support | 2021 |
| Fran Supermarket Ltd | Wholesale & retail | 2021 |
| Franbell Holdings Ltd | Real estate | 2022 |
| Franc Construction Ltd | Construction | 2020 |
| Francesca Page Ltd | Professional & scientific | 2022 |
| Francez Limited | Transport & logistics | 2019 |
| Francis Group Limited | Real estate | 2012 |
| Francis Hill Property Ltd | Real estate | 2026 |
| Francis Pub's Ltd | Health & social care | 2026 |
| Francis Stribling Limited | Real estate | 2018 |
| Franco-British Colony for Convalescents(Incorporated)(The) | Health & social care | 1919 |
| Francys Ltd | Transport & logistics | 2018 |
| Frank and Steiner Ltd | Extraterritorial | 2022 |
| Frankbrown Aviation Ltd | Manufacturing | 2023 |
| Frankdriana Ltd | Wholesale & retail | 2026 |
| Franklin Gilmore Limited | Construction | 2012 |
| Franklin Medical Solutions Limited | Extraterritorial | 2024 |
| Franklin Point Management Company Limited | Households | 2003 |
| Franklins Solicitors LLP | | 2003 |
| Frankly Consult Limited | Professional & scientific | 2010 |
| Frankwell Furniture Ltd | Wholesale & retail | 2021 |
| Fraser & Co. Talent Partners Limited | Administrative & support | 2026 |
| Fraser Pearce Consulting Limited | Professional & scientific | 2013 |
| Frasershot Limited | Professional & scientific | 2007 |
| Freaddy Company Limited | Professional & scientific | 2016 |
| Fred and Olive's Fine Foods Limited | Professional & scientific | 2025 |
| Fred and Olive's Ltd | Hospitality | 2016 |
| Fred Tomlin & Co.Limited | Professional & scientific | 1934 |
| Fred Wood & SON Limited | Agriculture & fishing | 1958 |
| Freddy PJ PUB Ltd | Hospitality | 2024 |
| Frederick's Landscaping Limited | Administrative & support | 2022 |
| Fredric Saunders Ltd | Transport & logistics | 2019 |
| Free 2 Talk Community Interest Company | Health & social care | 2008 |
| Free 2 Talk Development CIC | Professional & scientific | 2024 |
| Free Flow Gutter Cleaning Ltd | Construction | 2025 |
| Free Spirit Investments Limited | Real estate | 2020 |
| Freebnk Holdings Limited | Financial services | 2022 |
| Freedom Fulfilment Ltd | Real estate | 2022 |
| Freedom Street Ltd | Education | 2023 |
| Freedom Strider Ltd | Information & communication | 2019 |
| Freedrik Limited | Construction | 2016 |
| Freefoam Building Products (UK) Limited | Manufacturing | 1999 |
| Freeman Automotive (UK) Ltd | Wholesale & retail | 1983 |
| Freeman Finance Limited | Other services | 2004 |
| Freemans Court Management Company Ltd | Households | 2018 |
| Freemasons Hall Northampton Limited | Hospitality | 1888 |
| Freenewable Energy Ltd | Professional & scientific | 2024 |
| Freestyle Freelance Ltd | Information & communication | 2021 |
| Freeta Logistics Limited | Transport & logistics | 2025 |
| Freeta Ltd | Real estate | 2021 |
| Freetimers Digital Limited | Information & communication | 2023 |
| Freezer Solutions Limited | Hospitality | 2016 |
| Freight Line Europe (UK) Limited | Transport & logistics | 2009 |
| Freight Masters Logistics Ltd | Transport & logistics | 2025 |