| Fieldview Systems Limited | Information & communication | 2013 |
| Figgie (G.B.) Limited | Professional & scientific | 1959 |
| Figgie (U.K.) Limited | Professional & scientific | 1985 |
| Figgie Sportswear (U.K.) Limited | Professional & scientific | 1982 |
| Figgie Sportswear Limited | Professional & scientific | 1952 |
| Filmgears UK Ltd | Administrative & support | 2019 |
| Finance Desk Ltd | Other services | 2016 |
| Fincarol Ltd | Professional & scientific | 2017 |
| Find YOU a Car Ltd | Wholesale & retail | 2009 |
| Finding Future Focus Ltd | Real estate | 2022 |
| Finding Paradise Ltd | Education | 2022 |
| Finishii Projects Limited | Construction | 2025 |
| Finlay Property Group Ltd | Real estate | 2023 |
| Fiona Jones Ltd | Information & communication | 2019 |
| Fire Door Services Limited | Extraterritorial | 2008 |
| Fire Marshal Recruitment Limited | Professional & scientific | 2020 |
| Fire Marshal Solutions Limited | Professional & scientific | 2020 |
| Fire Marshal Staffing Limited | Professional & scientific | 2020 |
| Fire Safety Platform UK Limited | Financial services | 2026 |
| Fire Sky Media Ltd | Information & communication | 2022 |
| Fire Systems Assist Ltd | Construction | 2024 |
| Firecat Ltd. | Extraterritorial | 2012 |
| Fireflash Lighting Limited | Construction | 2021 |
| First Class Beauty and Cosmetics Ltd | Wholesale & retail | 2021 |
| Fitzgerald Fostering & Consultancy Limited | Professional & scientific | 2007 |
| Five Pharm Ltd | Wholesale & retail | 2018 |
| FIVE01 Platform Ltd | Information & communication | 2025 |
| Fivestar Landscapes Limited | Administrative & support | 2020 |
| FIX My Wheels Limited | Wholesale & retail | 2021 |
| Fix-It Frankel Ltd | Construction | 2026 |
| Fixforward Partners Limited | Professional & scientific | 2026 |
| Fkdrive Ltd | Transport & logistics | 2023 |
| Flame & Water Services Limited | Construction | 2017 |
| Fleks Digital Ltd | Information & communication | 2025 |
| Fleming and Sons Limited | Construction | 2015 |
| Flexcargo Limited | Wholesale & retail | 2020 |
| Flexchef Limited | Hospitality | 2023 |
| Flexed London Ltd | Wholesale & retail | 2025 |
| Flexera Software Holdings Limited | Financial services | 2015 |
| Flexera Software Limited | Information & communication | 2008 |
| Flexible Resourcing Limited | Professional & scientific | 2016 |
| Flexpress Couriers Ltd | Transport & logistics | 2024 |
| Flightpath Group Limited | Financial services | 2026 |
| Flippa Ltd | Construction | 2025 |
| Flora Business Ltd | Health & social care | 2021 |
| Flower Connect Ltd | Wholesale & retail | 2026 |
| Flowfix Plumbing & Drainage Ltd | Construction | 2025 |
| Floworks Engineering Ltd | Professional & scientific | 2019 |
| Flush Sporting Ltd | Administrative & support | 2022 |
| Flying Colours Advice Limited | Financial services | 2014 |
| Flying Colours Holdings Limited | Financial services | 2019 |
| Flying Colours Investment Management Limited | Financial services | 2020 |
| Flying Colours Limited | Financial services | 2021 |
| Flying Colours Mortgages Limited | Financial services | 2022 |
| Flying Colours Partnerships Limited | Administrative & support | 2019 |
| Flying Colours Services Limited | Administrative & support | 2019 |
| Flying Saucer Treats Ltd | Wholesale & retail | 2022 |
| FNG Supplies Ltd | Information & communication | 2010 |
| Focus Real Estate Limited | Real estate | 2016 |
| FOD. (Forever on Digital) Ltd | Professional & scientific | 2024 |
| Fonehouse Services Limited | Wholesale & retail | 2023 |
| Football FUN Factory (Community 072) Limited | Arts & recreation | 2022 |
| Forest Cleaning Services Ltd | Administrative & support | 2020 |
| Forest Executive Cars Bracknell Limited | Transport & logistics | 2013 |
| Forest Future Homes Limited | Construction | 2013 |
| Forest Park Garage Doors Ltd | Construction | 2024 |
| Forest Park Homes Ltd | Real estate | 2025 |
| Forestbarbers Limited | Other services | 2023 |
| Forever Buys Ltd | Wholesale & retail | 2022 |
| Fornax Direct Limited | Wholesale & retail | 2015 |
| Foroma Collective Limited | Wholesale & retail | 2022 |
| Fortareach Ltd | Other services | 2025 |
| Fortis Investments Group Limited | Real estate | 2024 |
| Fortis Investments Holdings Limited | Real estate | 2024 |
| Fortune Jack’S Food Limited | Hospitality | 2024 |
| Forum Tiles Limited | Construction | 2021 |
| Foster Growth Ltd | Administrative & support | 2003 |
| Foxley Court Residents Association Limited | Administrative & support | 1993 |
| FP Mailing (HCS) Limited | Administrative & support | 2012 |
| Fractalogix Ltd | Information & communication | 2014 |
| Francesca Green Acupuncture Limited | Health & social care | 2019 |
| Franklin Bay Limited | Financial services | 2019 |
| Frazer Simpson Limited | Wholesale & retail | 2009 |
| Freeads Classifieds Limited | Other services | 2002 |
| Freeman Eyewear Ltd | Wholesale & retail | 2018 |
| Freeman Recruitment Ltd | Administrative & support | 2026 |
| Frella Roofing Services Ltd | Construction | 2025 |
| French Erection Ltd. | Information & communication | 2011 |
| Fresh AS a Daisy (Berkshire) Ltd | Administrative & support | 2024 |
| Fresnoy UK Limited | Professional & scientific | 2012 |
| Friedland Doggart Group Limited | Professional & scientific | 1963 |
| Friendly Faces Events Ltd | Other services | 2026 |
| FRM Property Management Limited | Real estate | 2021 |
| Frobisher Professional Services Ltd | Financial services | 2020 |
| Frontline Spridget Limited | Wholesale & retail | 1995 |
| Frost Services (South East) Ltd | Construction | 2024 |
| FRS Pension Trustee Company Limited | Financial services | 2010 |
| Fruitcase Ltd | Manufacturing | 2015 |
| FS Elite Academy Ltd | Wholesale & retail | 2026 |
| Fsas Technologies Limited | Information & communication | 2025 |