| Flint TV EBT Company Ltd | Professional & scientific | 2017 |
| Flintlab Ltd | Real estate | 2019 |
| Flip Focus Limited | Administrative & support | 2025 |
| Flipbox Design Ltd | Other services | 2022 |
| Flo-Fitouts Ltd | Construction | 2022 |
| Flo-San Ltd | Manufacturing | 2020 |
| Floe Newcastle Ltd | Real estate | 2021 |
| Floe Technology Limited | Information & communication | 2024 |
| Floki's Lodge Ltd | Hospitality | 2024 |
| Flooded Cellar Productions Limited | Information & communication | 2002 |
| Floortec NE Limited | Construction | 2017 |
| Florence (NE) Ltd | Hospitality | 2025 |
| Florentis Ltd | Real estate | 2025 |
| Floryan Services Limited | Construction | 2025 |
| Flourish Global Multi Ventures Ltd | Administrative & support | 2026 |
| Flourish Greens Ltd | Professional & scientific | 2012 |
| Flourish With FIG Ltd | Administrative & support | 2023 |
| Flow Converts Limited | Professional & scientific | 2022 |
| Flow Software Solutions Ltd | Information & communication | 2019 |
| Flower Drinks Ltd | Real estate | 2022 |
| Flowering Rosemary Ltd | Wholesale & retail | 2024 |
| Flowers by Angel Blooms Ltd | Wholesale & retail | 2024 |
| Flowers in the Dark Limited | Manufacturing | 2025 |
| Flowlogicks Consulting Ltd | Administrative & support | 2022 |
| Fluid Bookkeeping Ltd | Professional & scientific | 2022 |
| Fluid Focus Ltd | Information & communication | 2022 |
| Flux Production Services Ltd | Professional & scientific | 2011 |
| FLY WHEELS25 Ltd | Transport & logistics | 2025 |
| Flying Crooked Ltd | Professional & scientific | 2025 |
| Flying Luck Ltd | Hospitality | 2026 |
| Flynn Waste Management Services Ltd | Water & waste | 2018 |
| FM (North-East) Ltd | Health & social care | 2014 |
| FMA Agency Limited | Professional & scientific | 2010 |
| FMC Kongsberg Services Limited | Mining & quarrying | 2003 |
| FMC Technologies Limited | Mining & quarrying | 1931 |
| FMC Technologies Pension Plan Limited | Financial services | 1991 |
| Fmc/Kos West Africa Limited | Professional & scientific | 1959 |
| FMS North Ltd | Administrative & support | 2018 |
| FND Motors Limited | Wholesale & retail | 2025 |
| Foams Superstore (UK) Ltd | Manufacturing | 2019 |
| Foca Partners Limited | Professional & scientific | 2023 |
| Focusify Ltd | Administrative & support | 2024 |
| Foilbae Ltd | Manufacturing | 2023 |
| FOJ Consultancy Services Ltd | Information & communication | 2019 |
| Foliot Investments | Financial services | 2020 |
| Fones Down Ltd | Arts & recreation | 2025 |
| Fonextra Distribution Ltd | Information & communication | 2020 |
| Fonextra Franchise Ltd | Information & communication | 2020 |
| Fonextra Master Franchise Ltd | Administrative & support | 2020 |
| Fonextra Scot Franchise Limited | Administrative & support | 2020 |
| Fonextra UK Franchise Ltd | Administrative & support | 2020 |
| Food by the River Limited | Hospitality | 2026 |
| Food Nation CIC | Health & social care | 1996 |
| Foodamatic Ltd | Wholesale & retail | 2025 |
| Foodco UK LLP | | 2001 |
| Foodybeeuk Ltd. | Information & communication | 2023 |
| Foolish Magpie Limited | Wholesale & retail | 2025 |
| Footandankledurham Ltd | Health & social care | 2024 |
| Football Fantasista Limited | Manufacturing | 2023 |
| Football Squirts Limited | Education | 2012 |
| Football Transfer Forum Limited | Arts & recreation | 2000 |
| Footprints Consulting Ltd | Professional & scientific | 2020 |
| Footsteps Children's Services Ltd | Education | 2009 |
| FOR Brothers North East Limited | Hospitality | 2022 |
| FOR Ourselves Community Interest Company | Arts & recreation | 2026 |
| FOR the Trees Limited | Wholesale & retail | 2021 |
| Forbes and Hamilton Ltd | Professional & scientific | 2025 |
| Forbes Young Accountancy Ltd | Professional & scientific | 2010 |
| Forbesflare Limited | Wholesale & retail | 2025 |
| Force Supplies Ltd | Wholesale & retail | 2010 |
| Forcemanager Ltd | Information & communication | 2014 |
| Ford Pharma Aesthetics Ltd | Health & social care | 2024 |
| Foreman Builds Limited | Construction | 2021 |
| Forest Green Block 1 Management Limited | Real estate | 2004 |
| Forest Green Block 2 Management Limited | Real estate | 2005 |
| Forest Hall Carpets Limited | Construction | 1972 |
| Forest Hall Community Tennis Club Limited | Arts & recreation | 2019 |
| Forest Hall Pilates Ltd | Arts & recreation | 2025 |
| Forest Hall Property Ltd | Real estate | 2022 |
| Forest Hall Studios Limited | Other services | 2025 |
| Forest Projects Limited | Construction | 2018 |
| Forest Residential Care Limited | Real estate | 2009 |
| Forestcore Energy Ltd | Manufacturing | 2025 |
| Forge and Field Ltd | Administrative & support | 2025 |
| Forge Beyond Ltd | Professional & scientific | 2023 |
| Forge Technical Services Limited | Professional & scientific | 2013 |
| Forged in Fear Productions Limited | Education | 2026 |
| Forget ME NOT Lodge Limited | Hospitality | 2019 |
| Forgiven Much Ltd | Professional & scientific | 2023 |
| Forgotten Studio Limited | Information & communication | 2026 |
| Forgrave Ltd | Health & social care | 2023 |
| Form Eighty Limited | Manufacturing | 2022 |
| Formation (N E) Ltd | Wholesale & retail | 2012 |
| Former Coroners Court Ltd | Professional & scientific | 2019 |
| Forms Online Ltd | Information & communication | 2010 |
| FORMS4U Limited | Extraterritorial | 2007 |
| Forough Ltd | Information & communication | 2025 |
| Forrest Family Office Ltd | Real estate | 2022 |
| Forrest Outdoors Ltd | Arts & recreation | 2024 |
| Forrest Property Holdings Ltd | Real estate | 2024 |