| Finds AI Ltd | Wholesale & retail | 2026 |
| Finest Carpentry Ltd | Construction | 2010 |
| Finestream Limited | Administrative & support | 2012 |
| Finncon Limited | Construction | 2023 |
| Finnova Limited | Information & communication | 2015 |
| Fiofro Limited | Professional & scientific | 2014 |
| Fipkin Family Properties Ltd | Real estate | 2026 |
| Fire Door Project Management Ltd | Professional & scientific | 2023 |
| Fire Films Ltd | Information & communication | 2024 |
| Fire Protect Ltd | Construction | 2013 |
| Fire Services and Supplies Limited | Public administration | 2009 |
| Fire System Solutions Limited | Administrative & support | 2009 |
| Fireaway Pizza High Wycombe Ltd | Hospitality | 2021 |
| Firestop Services Limited | Public administration | 2003 |
| Firex U.K. Limited | Other services | 2001 |
| Firmware Integrations SAI UK Ltd | Wholesale & retail | 2022 |
| Firs Close Estate Limited | Households | 1967 |
| First Choice Airport Transfers Ltd | Transport & logistics | 2017 |
| First Choice Autz Ltd | Wholesale & retail | 2026 |
| First Choice Car HW Limited | Transport & logistics | 2024 |
| First Choice Decorating & Construction Ltd | Construction | 2025 |
| First Choice Homz Ltd | Wholesale & retail | 2025 |
| First Choice Marshalls Limited | Wholesale & retail | 1987 |
| First Front Logistics Ltd | Transport & logistics | 2017 |
| First Growth Bordeaux Limited | Other services | 2006 |
| First Look Construction Ltd | Construction | 2025 |
| First Move Marketing Services Limited | Administrative & support | 1989 |
| First Soccer Ltd | Arts & recreation | 2013 |
| First Step Financial Services Ltd | Professional & scientific | 2017 |
| First Step Technologies Ltd | Other services | 2023 |
| Firstaid Medics Limited | Extraterritorial | 2025 |
| Firstcall Painting Ltd | Construction | 2023 |
| Firstscapes Ltd | Administrative & support | 2026 |
| FIS Blackstone Limited | Professional & scientific | 2016 |
| Fisc Financial Services Limited | Information & communication | 2018 |
| Fistbump Marketing Ltd | Professional & scientific | 2025 |
| Fit & Healthy Solutions Limited | Health & social care | 2017 |
| Fit for Films Limited | Administrative & support | 2014 |
| Fit Minds Limited | Extraterritorial | 2015 |
| Fitness Management Solutions Limited | Arts & recreation | 1999 |
| Fitness Professionals Network Limited | Administrative & support | 2024 |
| Fits Networks Ltd | Information & communication | 2017 |
| Fitted Home Alarms Limited | Manufacturing | 2011 |
| Fitz Air Limited | Administrative & support | 2009 |
| Fitzgerald Furniture (Holdings) Limited | Professional & scientific | 2002 |
| Five Acre Properties Limited | Real estate | 2005 |
| Five Bells LLP | | 2010 |
| Five Go Live Limited | Information & communication | 2005 |
| Five Pillars Limited | Administrative & support | 2000 |
| Five Star Nails 110 Ltd | Other services | 2026 |
| Five to Nine Creative Ltd | Professional & scientific | 2025 |
| Fivestores Limited | Wholesale & retail | 2026 |
| Fixer Upper Services Ltd | Other services | 2025 |
| Fixinguk.Com Limited | Construction | 2026 |
| Fixitcompany Ltd | Other services | 2022 |
| Fizzy Fuzzy Ltd | Manufacturing | 2017 |
| Flackwell Boxing and Fitness Hub Ltd | Other services | 2023 |
| Flackwell Heath Golf Club Limited | Arts & recreation | 1920 |
| Flackwell Investments Limited | Financial services | 2022 |
| Flagfin Trading Ltd | Information & communication | 2013 |
| Flagstone Limited | Administrative & support | 2007 |
| Flamemain Limited | Real estate | 1984 |
| Flash PAD Ltd | Other services | 2021 |
| Flashlight Limited | Wholesale & retail | 2002 |
| Flat 1 High Street Ltd | Real estate | 2025 |
| Flat SIX Motorsport Limited | Professional & scientific | 2024 |
| Flatline Detailing Ltd | Wholesale & retail | 2021 |
| Flaxen Logistics Limited | Information & communication | 2016 |
| Fleetwood Aviation Limited | Professional & scientific | 2025 |
| Flegg Properties Ltd | Real estate | 2024 |
| Flex White Ltd | Health & social care | 2022 |
| Flex World Autos Limited | Wholesale & retail | 2024 |
| Flexible Provisions Ltd | Health & social care | 2013 |
| Flexity Ltd | Other services | 2010 |
| Flexnpose Ltd | Wholesale & retail | 2020 |
| Flight & Light Ltd. | Construction | 2017 |
| Flightline Sporting Limited | Arts & recreation | 2022 |
| Flitset Properties Limited | Real estate | 1998 |
| FLM Electrical Services Limited | Construction | 2004 |
| Floodscreen Ltd | Manufacturing | 2014 |
| Floor IT Trade Sales Limited | Wholesale & retail | 2018 |
| Floorless Floors Limited | Wholesale & retail | 2012 |
| Floral Court Management Company Limited | Households | 2000 |
| Flow Pilates Studios Ltd | Arts & recreation | 2025 |
| Flowdowel Limited | | 1981 |
| Flush Golf Limited | Extraterritorial | 2020 |
| Flux Photographic Ltd | Arts & recreation | 2014 |
| FLY Safari UK Ltd | Administrative & support | 2024 |
| Flybird Ltd | Wholesale & retail | 2014 |
| Flying Test Systems Limited | Professional & scientific | 2004 |
| Flyover House Limited | Extraterritorial | 1995 |
| Flysend Ltd | Administrative & support | 2025 |
| Fmbs and Magnet Medics Limited | Manufacturing | 2004 |
| Fmct Global Ltd | Professional & scientific | 2023 |
| Fmct Holdings Ltd | Professional & scientific | 2025 |
| FNE Telecoms Ltd | Information & communication | 2019 |
| Foam Experts London Ltd | Manufacturing | 2024 |
| Foam World Ltd | Manufacturing | 2024 |
| Focus 4 Housing | Real estate | 2020 |
| Focus Apps Ltd | Information & communication | 2025 |