| Fortescue Energy Ventures Ltd | Financial services | 2024 |
| Fortescue Future Industries United Kingdom Holdings Limited | Financial services | 2023 |
| Fortescue UK Services Ltd | Financial services | 2023 |
| Fortice Ltd | Administrative & support | 2009 |
| Fortified Distribution Ltd | Wholesale & retail | 2025 |
| Fortis Building Limited | Construction | 2022 |
| Fortis in Fiducia Ltd | Financial services | 2024 |
| Fortis Tyres Limited | Wholesale & retail | 2015 |
| Fortiset Security Ltd | Administrative & support | 2025 |
| Fortitude for Life Ltd | Professional & scientific | 2020 |
| Fortitude Property Group Ltd | Financial services | 2024 |
| Fortius PE Limited | Education | 2013 |
| Fortius Swimming Limited | Education | 2024 |
| Fortomenos Limited | Wholesale & retail | 2025 |
| Fortress Accommodation Rentals Ltd | Real estate | 2021 |
| Fortress Construction Ltd | Construction | 2008 |
| Fortress Fire Ltd | Extraterritorial | 2022 |
| Fortuis Media Limited | Professional & scientific | 2011 |
| Fortuna Redux Ltd | Other services | 2023 |
| Fortune 2828 Limited | Real estate | 2019 |
| Fortune Business Development Ltd | Administrative & support | 2024 |
| Fortune Carpentry & Joinery Limited | Construction | 2015 |
| Fortune Future Limited | Hospitality | 2022 |
| Fortune Takeaway Skegness Ltd | Hospitality | 2025 |
| Fortunex Limited | Administrative & support | 2017 |
| Forty 2 Properties (Bristol) Ltd | Real estate | 2023 |
| Forty Nine Oakfield Road Management Limited | Households | 2002 |
| Forty Two & a Half Ltd | Professional & scientific | 2024 |
| Fortyx Technologies Ltd | Information & communication | 2024 |
| Forward ESG Ltd | Professional & scientific | 2022 |
| Forward Learning and Development Ltd | Professional & scientific | 2010 |
| Forward Momentum Ltd | Information & communication | 2022 |
| Forward Planning & Development Limited | Professional & scientific | 2014 |
| Forward Surveying & Design Limited | Professional & scientific | 2015 |
| Forward Thinking (Bristol) Limited | Financial services | 2023 |
| Forward Thinking Recruitment Limited | Administrative & support | 2015 |
| Forza Consulting Limited | Administrative & support | 2024 |
| Forza Rail Limited | Administrative & support | 2022 |
| Fosa Limited | Health & social care | 2014 |
| Fosdak Ltd | Information & communication | 2023 |
| Fosscape Lighting Ltd | Manufacturing | 2024 |
| Fossebridge Electrical Limited | Construction | 2025 |
| Fossedale Properties Limited | Construction | 1992 |
| Fosseway Training Ltd | Construction | 2023 |
| Fossil Beach Holdings Ltd | Real estate | 2024 |
| Foster Management & Consultancy Ltd | Financial services | 2026 |
| Foster Technology Limited | Professional & scientific | 2023 |
| Fostering Families Foundation CIC | Health & social care | 2026 |
| Fosterli Ltd | Information & communication | 2024 |
| Fosters Jewellers Ltd | Extraterritorial | 2008 |
| Fothergill Family Investment Company Limited | Professional & scientific | 2021 |
| Fothergill Films Limited | Information & communication | 2007 |
| Fothergill Park Management Company Limited | Households | 2025 |
| Foto Sounds UK Ltd | Wholesale & retail | 2021 |
| Found Store Limited | Wholesale & retail | 2023 |
| Foundation for Leadership Through Sport | Arts & recreation | 2010 |
| Foundation Partners Limited | Professional & scientific | 2023 |
| Foundations ARC | Health & social care | 2025 |
| FOUNDATIONS4SUCCESS Ltd | Health & social care | 2022 |
| Founded & Grounded Limited | Professional & scientific | 2018 |
| Founded Wellness Ltd | Administrative & support | 2016 |
| Founder Fidus Ltd | Administrative & support | 2024 |
| Foundry Asset Management Limited | Real estate | 2018 |
| Foundry Formulas Ltd | Manufacturing | 2023 |
| Foundry LEA (Bridport) Management Company Limited | Households | 2023 |
| Fountain Court (Yate) Management Company Limited | Households | 1991 |
| Fountain International Limited | Real estate | 1969 |
| Fountain Mill Project Limited | Real estate | 2006 |
| Fountain Print Limited | Manufacturing | 1997 |
| Fountain Timber Products Limited | Manufacturing | 1942 |
| Fountain Treeworks Ltd | Agriculture & fishing | 2011 |
| Fountainhead Software Ltd | Information & communication | 2014 |
| Four Aces Bar Ltd | Hospitality | 2026 |
| Four Corners Public Relations Limited | Information & communication | 2006 |
| Four Folds Group Limited | Hospitality | 2025 |
| Four Forward Property Limited | Real estate | 2026 |
| Four Iddesleigh Road Management Limited | Real estate | 1986 |
| Four J'S Development Tools (UK) Ltd | Professional & scientific | 2005 |
| Four Lakes Limited | Arts & recreation | 2016 |
| Four Legs Four Walls Ltd | Wholesale & retail | 2018 |
| Four Market Street Ltd | Other services | 2013 |
| Four Neighbours Ltd | Construction | 2026 |
| Four Property International (Pinnigers) Limited | Construction | 2019 |
| Four Property International Limited | Construction | 2019 |
| Four Seas (Climate Change Cohousing Community) Ltd | Professional & scientific | 2022 |
| Four Seasons & YOU Ltd | Wholesale & retail | 2026 |
| Four Seasons 4U Ltd | Wholesale & retail | 2024 |
| Four Seasons Gardeners Limited | Administrative & support | 2023 |
| Four Seasons Landscapes Limited | Extraterritorial | 1999 |
| Four Seasons Takeaway Bristol Limited | Hospitality | 2026 |
| Four Shires Holding Company Limited | Financial services | 2023 |
| Four Spires Solutions Ltd | Wholesale & retail | 2025 |
| Four Stacks Ltd | Information & communication | 2011 |
| Four Stokes Ltd | Real estate | 2024 |
| Four Times Enterprises Limited | Professional & scientific | 2010 |
| Four Two Five Limited | Real estate | 2022 |
| Four Valent Limited | Information & communication | 2020 |
| Four Walls Consultants Limited | Construction | 2005 |
| Four Wheel Drive Productions Limited | Administrative & support | 2018 |
| Fouracre Dwellings Ltd | Real estate | 2023 |