| Food Innovation Technology Limited | Hospitality | 2025 |
| Food Network Ltd | Wholesale & retail | 1999 |
| Food Plus Macius Ltd | Wholesale & retail | 2026 |
| Food Rush Catering Ltd | Hospitality | 2018 |
| Footloose Sailing Ltd | Arts & recreation | 2023 |
| Foraction Limited | Other services | 2013 |
| Foras (Chertsey Road) Limited | Construction | 2023 |
| Foras (Sparkle Street) Limited | Construction | 2022 |
| Ford Family Funeral Directors Ltd | Other services | 2023 |
| Fordham Holdings Limited | Real estate | 2026 |
| Fordis Capital Ltd | Administrative & support | 2023 |
| Foreign Rhythm Music Ltd | Arts & recreation | 2020 |
| Forest & Coleman Limited | Health & social care | 2024 |
| Forest Chigwell Limited | Professional & scientific | 2007 |
| Forest Crowthorne Limited | Professional & scientific | 2007 |
| Forest Faringdon Limited | Professional & scientific | 2007 |
| Forest Gillingham Limited | Professional & scientific | 2007 |
| Forest Great Missenden Limited | Professional & scientific | 2007 |
| Forest Green Consultants Limited | Professional & scientific | 2026 |
| Forest Healthcare Acquisitions Limited | Professional & scientific | 2007 |
| Forest Healthcare Finance Limited | Financial services | 2007 |
| Forest Healthcare Limited | Professional & scientific | 1994 |
| Forest Healthcare Operations Limited | Professional & scientific | 2007 |
| Forest Hingham Limited | Professional & scientific | 2007 |
| Forest Maidstone Limited | Professional & scientific | 2007 |
| Forest New Barnet Limited | Professional & scientific | 2007 |
| Forest Wokingham Limited | Professional & scientific | 2007 |
| Forever Camden Ltd | Real estate | 2026 |
| Forge Zone Fitness Ltd | Arts & recreation | 2025 |
| Forja Entertainment Ltd | Information & communication | 2011 |
| Forkley Logistics LLP | | 2016 |
| Forman Effects Ltd | Manufacturing | 2023 |
| Formz Music Ltd | Information & communication | 2021 |
| Fornova UK Limited | Information & communication | 2011 |
| Fort & Manor Ltd | Education | 1987 |
| Fort Secure Ltd | Information & communication | 2017 |
| Fortacre Private Credit Limited | Financial services | 2026 |
| Forthlease Limited | Professional & scientific | 1996 |
| Fortis Fire and Security Limited | Construction | 2022 |
| Fortis Green Road RTM Company Limited | Households | 2006 |
| Fortishield Security Ltd | Administrative & support | 2025 |
| Fortissimo Operations LLP | | 2015 |
| Fortyeight Trading Limited | Wholesale & retail | 2026 |
| Fotoshooters Limited | Information & communication | 2017 |
| Foundation Investments Limited | Real estate | 1983 |
| Fountain Management Consultancy Ltd | Administrative & support | 2014 |
| Fountayne Managing Ltd | Real estate | 2015 |
| Four by Two Limited | Information & communication | 2002 |
| Four One Ealing Limited | Construction | 2025 |
| Four Square Family Investments Ltd | Financial services | 2019 |
| Fourdot Affinity Limited | Manufacturing | 2012 |
| Fourdot Plates Limited | Manufacturing | 2026 |
| Fourpoint Architects LLP | | 2006 |
| Fourteen Property Investments Limited | Real estate | 2025 |
| FOX & ORR Holdings Ltd | Financial services | 2023 |
| Foxcraft Carpentry Ltd | Manufacturing | 2025 |
| FPF Groundworks Limited | Construction | 2025 |
| FPF Utilities Limited | Construction | 2012 |
| Fpfu Holdings Limited | Financial services | 2025 |
| FPR Basement Limited | Real estate | 2025 |
| FR Bridal Limited | Manufacturing | 2021 |
| Framed London Limited | Manufacturing | 2023 |
| Framefox Ltd | Professional & scientific | 2025 |
| Frankly Great Desserts Limited | Manufacturing | 2016 |
| Fraul Home Automation Ltd | Administrative & support | 2024 |
| Fredi Tiling Ltd | Construction | 2018 |
| Free Logistics Limited | Transport & logistics | 2020 |
| Free to Learn Ltd | Education | 2010 |
| Freeborn Salisbury Limited | Wholesale & retail | 2021 |
| Freedcut Ltd | Arts & recreation | 2018 |
| Freedmans Law Limited | Professional & scientific | 2026 |
| Freeform Curtain Wall Ltd | Construction | 2019 |
| Freeman & Hook Scaffolding Contractors Limited | Construction | 1997 |
| Freestylers Music Limited | Information & communication | 2014 |
| Fremas Care Limited | Health & social care | 2021 |
| Fresh Breeze Laundry Ltd | Other services | 2024 |
| Fresh Line Limited | Hospitality | 2016 |
| Fresh Wharf Residents Managment Company Limited | Households | 2019 |
| Freshmax Ltd | Manufacturing | 2004 |
| Freshshields Limited | Real estate | 1998 |
| Frevara Group Holdings Limited | Financial services | 2025 |
| Frewin Construction Limited | Information & communication | 2019 |
| Fricktion Music Limited | Arts & recreation | 2014 |
| Friday Construction Ltd | Construction | 2019 |
| Friends of OHR Aaron, David Cardozo Academy | Education | 2010 |
| Fringewood Properties Limited | Real estate | 2016 |
| Frithsden Construction (UK) Limited | Construction | 2011 |
| Fromtame Ltd | Administrative & support | 2024 |
| Front Point Wealth Ltd | Professional & scientific | 2019 |
| Frostica Air Conditioning Ltd | Manufacturing | 2026 |
| FRS Surfacing Ltd | Construction | 2017 |
| FRU Plumbing & Heating Limited | Construction | 2023 |
| Fruitful Enterprises Limited | Financial services | 2024 |
| Fruitful Office Holdings Limited | Financial services | 2020 |
| Fruitful Office Limited | Hospitality | 2005 |
| FSG Drylining Ltd | Construction | 2025 |
| FSR Management Limited | Professional & scientific | 1999 |
| FT Manufacturing Limited | Manufacturing | 2022 |
| Fubb Ltd | Real estate | 2025 |
| Fufu Factory Europe Ltd | Wholesale & retail | 2024 |