| FB Curves 3D Gym Limited | Education | 2017 |
| FB Curves 3D Gym MEN Limited | Extraterritorial | 2018 |
| FB Curves 3D Gym Trampoline Limited | Extraterritorial | 2018 |
| FB Curves 3D Gym Women Limited | Extraterritorial | 2018 |
| FBA Formula Ltd | Education | 2025 |
| FBF Engineering Survey Ltd | Professional & scientific | 2018 |
| FBJ Group Ltd | Hospitality | 2019 |
| FBL Properties Limited | Real estate | 2024 |
| FBS Faber Building Services Ltd | Construction | 2019 |
| Fbsa Technology Ltd | Information & communication | 2026 |
| Fbst Holdings Ltd | Professional & scientific | 2019 |
| FC Connection Ltd | Wholesale & retail | 2019 |
| FC Reporting Limited | Professional & scientific | 2019 |
| FCB Steakhouse Ltd | Hospitality | 2024 |
| FCE Yatirim Limited | Information & communication | 2025 |
| FCI Hitech Ltd | Other services | 2025 |
| FCI Services Limited | Extraterritorial | 2022 |
| Fclick Global Ltd | Manufacturing | 2025 |
| Fcrownner Yabin Ltd | Wholesale & retail | 2024 |
| FCT Elite Consulting Limited | Professional & scientific | 2018 |
| FCT Management Limited | Administrative & support | 2019 |
| Fcyc Ltd | Wholesale & retail | 2025 |
| FD Digital Globe Ltd | Financial services | 2025 |
| FD Estates Ltd | Financial services | 2024 |
| FD Media Ltd | Wholesale & retail | 2017 |
| FD02 Limited | Professional & scientific | 2016 |
| FDA Cleaning Cardiff Limited | Administrative & support | 2022 |
| FDA Maintenance Limited | Other services | 2020 |
| Fdan Global Ltd | Wholesale & retail | 2025 |
| FDR Group Ltd | Construction | 2019 |
| FDS Batiment Ltd | Financial services | 2017 |
| FDT Travel Ltd | Administrative & support | 2019 |
| Fdtw Ltd | Wholesale & retail | 2025 |
| FE Bursa LLP | | 2020 |
| FE Mhcf LLP | | 2020 |
| FE Wellness Group Ltd | Financial services | 2026 |
| Feabol Limited | Wholesale & retail | 2010 |
| Fearnley & Brown Limited | Other services | 2003 |
| Fears Data Solutions Limited | Information & communication | 2020 |
| Feather Invest - Instruments Management Ltd | Professional & scientific | 2025 |
| Featherhart Limited | Real estate | 2022 |
| Feature Fusion Ltd | Information & communication | 2017 |
| Featurestair Joinery Limited | Manufacturing | 2021 |
| Febicol Delux Ltd | Wholesale & retail | 2025 |
| FED Property Group Ltd | Real estate | 2024 |
| FED Restaurant Group Ltd | Hospitality | 2024 |
| FED Solutions PC | | 2020 |
| Feda Software Ltd | Information & communication | 2025 |
| Federated Homes Limited | | 1943 |
| Feducialucri Ltd | Professional & scientific | 2024 |
| FEE Greening Ltd | Arts & recreation | 2025 |
| FEE Holdings Limited | Real estate | 2023 |
| Feebledish Ltd | Health & social care | 2020 |
| Feeder Studios Productions Ltd | Hospitality | 2021 |
| Feedsauce Limited | Professional & scientific | 2017 |
| Feedspot Ltd | Information & communication | 2025 |
| Feel Fire Ltd | Professional & scientific | 2020 |
| Feel Petter Ltd | Other services | 2024 |
| Feelgood Bedding Ltd | Wholesale & retail | 2022 |
| Feelo Mart Ltd | Wholesale & retail | 2025 |
| Feelza Ltd | Information & communication | 2024 |
| Feet in Motion Ltd | Health & social care | 2015 |
| Feetsers Ltd | Wholesale & retail | 2025 |
| Feierabend Consulting | Administrative & support | 2026 |
| Feign Ltd | Other services | 2019 |
| Fekrah Enterprises Private Limited | Wholesale & retail | 2025 |
| Felcom Ltd | Transport & logistics | 2019 |
| Felicitas Consultancy Limited | Professional & scientific | 2023 |
| Felicitas Services Limited | Information & communication | 2004 |
| Felin Fach Management Company (Cardiff) Limited | Households | 2006 |
| Felix Cardiff Limited | Construction | 2025 |
| Felix Tech UK Ltd | Information & communication | 2018 |
| Felixstowe Cleaning Services Ltd | Administrative & support | 2019 |
| Fellas Grill House Ltd | Hospitality | 2024 |
| Fellows Floor Sanding Limited | Construction | 2022 |
| Felorah Clothing Ltd | Manufacturing | 2026 |
| Felsira Ltd | Education | 2025 |
| Fely PR Academy Ltd | Other services | 2024 |
| Femadexlink Ltd | Administrative & support | 2026 |
| Female Builders Limited | Construction | 2026 |
| Femella London | Other services | 2026 |
| Femial Limited | Wholesale & retail | 2021 |
| Femm UK Ltd | Hospitality | 2018 |
| Femme Fatel Limited | Other services | 2003 |
| Femtio Recruitment Ltd | Administrative & support | 2020 |
| Femversum Formula Ltd | Wholesale & retail | 2025 |
| Fenbrook Group Ltd | Wholesale & retail | 2026 |
| Fencing Fellas Ltd | Administrative & support | 2022 |
| Fenetre Glaze Ltd | Construction | 2023 |
| Feng HUA Xiang Limited | Wholesale & retail | 2021 |
| Fenghuo Cultural Media Limited | Information & communication | 2025 |
| Fengshuiheaven Ltd | Wholesale & retail | 2025 |
| Fenice Phoenix Ltd | Other services | 2023 |
| Fenix Builders Ltd | Construction | 2019 |
| Fennel Acquisition Limited | Financial services | 2006 |
| Fennemore Banks Limited | Administrative & support | 2005 |
| Fenomeno Fashion Ltd | Wholesale & retail | 2026 |
| Fenrir Creative Tech Ltd | Information & communication | 2025 |
| Fenrir Saas Technologies Ltd | Information & communication | 2025 |
| Fenris Strategic Solutions Ltd | Transport & logistics | 2018 |