| FF Sale Ltd | Arts & recreation | 2025 |
| Ffaim Ltd | Real estate | 2024 |
| Ffdcuk Ltd | Education | 2023 |
| FFF Chris Merriman Limited | Arts & recreation | 2026 |
| FFF Vintage Ltd | Wholesale & retail | 2026 |
| FFI Components Ltd | Wholesale & retail | 2024 |
| FFI Limited | Transport & logistics | 2016 |
| FFM Community Projects CIC | Other services | 2020 |
| Ffmb UK Ltd | Other services | 2017 |
| Ffolliott Bird Associates Limited | Health & social care | 2007 |
| FFR Consultant Ltd | Information & communication | 2017 |
| Ffrt Limited | Other services | 2025 |
| Ffskin Ltd | Wholesale & retail | 2026 |
| FFT Company Secretarial Limited | Extraterritorial | 2006 |
| FFT Holdco Limited | Financial services | 2025 |
| FG Building Consultancy Ltd | Professional & scientific | 2014 |
| FG Marketing Limited | Real estate | 2023 |
| FG Property Solutions Ltd | Real estate | 2024 |
| Fgat Ltd | Financial services | 2022 |
| FGF Business Solutions Ltd | Professional & scientific | 2025 |
| Fglr Resources Limited | Wholesale & retail | 2014 |
| FGM Associates Limited | Professional & scientific | 2000 |
| FH & Co Accountants Ltd | Professional & scientific | 2025 |
| FH Kitchens & Wardrobes Ltd | Manufacturing | 2025 |
| FH Luxe Limited | Wholesale & retail | 2025 |
| FH Mobiles Ltd | Wholesale & retail | 2019 |
| FH Real Estate Ltd | Real estate | 2023 |
| FHA Accountants Limited | Professional & scientific | 2025 |
| Fhenixcore Health Ltd | Health & social care | 2023 |
| FHM Express Limited | Transport & logistics | 2025 |
| FHM Express Logistics Ltd | Transport & logistics | 2023 |
| FHS Property Service Limited | Real estate | 2018 |
| Fhsq Limited | Real estate | 2018 |
| FHT Ltd | Information & communication | 2020 |
| FI Trust Corporation Limited | Administrative & support | 2025 |
| Fiac UK Limited | Extraterritorial | 1990 |
| Fiaz Foods Limited | Hospitality | 2026 |
| Fiaz Holding Limited | Financial services | 2021 |
| Fibi Services Ltd | Professional & scientific | 2022 |
| Fibi Trading UK Ltd | Wholesale & retail | 2020 |
| Fibka Ltd | Transport & logistics | 2026 |
| Fibonatix (UK) Limited | Financial services | 2015 |
| Fibre NET Consultancy Limited | Information & communication | 2015 |
| Fibre Ready Ltd | Information & communication | 2026 |
| Fibrecare Equipment & Consultants Limited | | 1978 |
| Fibrelink Network Solutions Ltd | Information & communication | 2014 |
| Fibremedy Limited | Manufacturing | 2026 |
| Fibrilx Limited | Information & communication | 2021 |
| Ficci Group Limited | Wholesale & retail | 2021 |
| Ficient Ltd | Wholesale & retail | 2024 |
| Fickling Medical Limited | Health & social care | 2013 |
| Fictorgymwear Ltd | Wholesale & retail | 2025 |
| Fida 4 Success Limited | Professional & scientific | 2018 |
| Fidana Trading Company Ltd | Wholesale & retail | 2025 |
| Fidari Investments Ltd | Real estate | 2025 |
| Fidatlas Limited | Wholesale & retail | 2021 |
| Fidaullah Khan for Trading and Investment Ltd | Wholesale & retail | 2021 |
| Fiddle Rock Ltd | Professional & scientific | 2022 |
| Fide Property Group Limited | Real estate | 2025 |
| Fidec Security Solutions Limited | Public administration | 2021 |
| Fidelis Care Ltd | Health & social care | 2026 |
| Fidelis Group Ltd | Administrative & support | 2016 |
| Fidelis Group Partnership LLP | | 2018 |
| Fidelis Lettings Ltd | Construction | 2026 |
| Fidelity Business Solutions Ltd | Professional & scientific | 2009 |
| Fidelity Finance and Investment Limited | Financial services | 2025 |
| Fidelity Gadgets Ltd | Wholesale & retail | 2025 |
| Fidesly Ltd | Professional & scientific | 2025 |
| Fido and Oak Limited | Wholesale & retail | 2025 |
| Fido PR Limited | Professional & scientific | 2001 |
| Fidrelis Group Limited | Professional & scientific | 2025 |
| FIDUCIA24 Ltd | Administrative & support | 2018 |
| Fiduciary Estate Services Ltd. | Extraterritorial | 2026 |
| Field Contracting Limited | Professional & scientific | 2026 |
| Field Invest Ltd | Real estate | 2022 |
| Field Nominees Limited | Extraterritorial | 2005 |
| Field Opportunities Limited | Administrative & support | 2013 |
| Field Property and Lettings Limited | Real estate | 2022 |
| Fielden Park Management Limited | Households | 1977 |
| Fieldex Joinery Limited | | 1969 |
| Fieldhead Estates Limited | Construction | 2025 |
| Fielding Commercials Ltd. | Wholesale & retail | 2017 |
| Fielding Flats Management Company Limited | Real estate | 2023 |
| Fielding Holdings Limited | Households | 2018 |
| Fieldman's Holiday Limited | Information & communication | 2013 |
| Fieldmasters ( North West ) Limited | Real estate | 2014 |
| Fields of Gold Festival Ltd | Information & communication | 2021 |
| Fieldstead Ltd | Real estate | 2025 |
| Fiera Dance Limited | Arts & recreation | 2023 |
| Fiera Ltd | Wholesale & retail | 2025 |
| Fiera Studios Limited | Arts & recreation | 2026 |
| Fierce Digitology Limited | Professional & scientific | 2022 |
| Fierce Institut Limited | Other services | 2025 |
| Fierce Property Ltd | Real estate | 2023 |
| Fierce Publications Ltd | Information & communication | 2023 |
| Fiery Cuisine Limited | Hospitality | 2024 |
| Fifab Limited | Professional & scientific | 2022 |
| Fifo Business Finance Ltd | Financial services | 2018 |
| Fifo Capital England Ltd | Financial services | 2016 |
| Fifteen Ladybarn Road Limited | Real estate | 2021 |