| Fleetwood Property Limited | Real estate | 2023 |
| Fleifal Plant & Machinery Limited | Administrative & support | 2019 |
| Flem Properties Ltd | Households | 2025 |
| Fleming and Bell Limited | Real estate | 2007 |
| Fleming Engineers Ltd | Professional & scientific | 2022 |
| Flemish Tapestries Limited | Extraterritorial | 1996 |
| Fletcher Consultancy Group Ltd | Professional & scientific | 2026 |
| Fletcher Power Limited | Professional & scientific | 2025 |
| Fletcher's Barn Management Company Limited | Households | 2005 |
| Fleur Care Support Services Limited | Health & social care | 2025 |
| Fleur Hair and Beauty Ltd | Other services | 2006 |
| Fleur Vaughan Ltd | Other services | 2024 |
| Flex Incorporated Ltd | Arts & recreation | 2020 |
| Flex Motors Ltd | Wholesale & retail | 2019 |
| Flex Reformer Pilates Limited | Arts & recreation | 2024 |
| Flexbay Limited | Real estate | 2017 |
| Flexi Concepts Ltd | Wholesale & retail | 2024 |
| Flexi Core Ltd | Wholesale & retail | 2023 |
| Flexi Equipment UK Ltd | Wholesale & retail | 2026 |
| Flexible Enterprises Limited | Professional & scientific | 2021 |
| Flextel Limited | Information & communication | 1992 |
| Flexus Management Ltd | Extraterritorial | 2016 |
| Flexxygi Limited | Professional & scientific | 2023 |
| Fliers Limited | Arts & recreation | 2024 |
| Flight Level Zero Limited | | 1973 |
| Flintrock Limited | Real estate | 2012 |
| FLM Consultants Ltd | Other services | 2025 |
| FLO Active Ltd | Wholesale & retail | 2024 |
| FLO Heating Limited | Construction | 2014 |
| FLO Holistics Ltd | Wholesale & retail | 2024 |
| FLO Wholesale Limited | Wholesale & retail | 2026 |
| Float Life Ltd | Health & social care | 2023 |
| Float Planet Ltd | Administrative & support | 2016 |
| Float Wellness UK Limited | Administrative & support | 2022 |
| Floating Horizons Holdings Ltd | Financial services | 2024 |
| Flood-Speed Developments Limited | Real estate | 2018 |
| Flooks Construction Services Ltd | Construction | 2024 |
| Floor 2 Wall Warehouse Ltd | Construction | 2018 |
| Floor Install UK Ltd | Construction | 2022 |
| Floorex NW Ltd | Construction | 2023 |
| Flooring Design Studio Ltd | Real estate | 2019 |
| Floorless Management Limited | Administrative & support | 2007 |
| Floorly Ltd | Wholesale & retail | 2017 |
| Floors 4 Sanding Ltd | Construction | 2010 |
| FLOORS4EVER UK Ltd | Wholesale & retail | 2024 |
| Floortec (UK) Ltd | Construction | 2007 |
| Flopps & Mill Limited | Financial services | 2019 |
| Floppy Trans Ltd | Transport & logistics | 2018 |
| Floradentix Ltd | Health & social care | 2026 |
| Florence Institute Trading Co Limited | Hospitality | 2011 |
| Florence Roby Limited | Manufacturing | 2003 |
| Florianni Ltd | Wholesale & retail | 2020 |
| Flouf Pets Limited | Information & communication | 2021 |
| Flour & Grape Liverpool Limited | Hospitality | 2026 |
| Flour Will FLY Ltd | Hospitality | 2023 |
| Flourish Therapies Ltd | Health & social care | 2021 |
| Flow and Glow Infusions Ltd | Other services | 2025 |
| Flow Buildings Ltd | Construction | 2025 |
| Flow Networks Ltd | Information & communication | 2014 |
| Flow Strategies Ltd | Professional & scientific | 2023 |
| Flow Tickets Limited | Information & communication | 2025 |
| Flowbridge Partners Limited | Manufacturing | 2026 |
| Flowerbug Floral Design Limited | Wholesale & retail | 2016 |
| Flowers & Favours Studio Ltd | Wholesale & retail | 2020 |
| Flowers by Elizabeth Ltd | Wholesale & retail | 2016 |
| Flowpro Limited | Information & communication | 2016 |
| Flowpro Services Ltd | Professional & scientific | 2025 |
| Flowsmith Systems Limited | Construction | 2025 |
| Flowstate Community CIC | Health & social care | 2022 |
| Floyd Fiber Limited | Information & communication | 2019 |
| FLR Removals Limited | Transport & logistics | 2024 |
| Flsupplies Ltd | Wholesale & retail | 2024 |
| Fluentia Ltd | Real estate | 2025 |
| Fluffy Stars Ltd | Information & communication | 2025 |
| Fluid and Fierce Ltd | Wholesale & retail | 2016 |
| Fluid Ventures Ltd | Information & communication | 2020 |
| Flush Films Ltd | Information & communication | 2020 |
| Flux Investments Limited | Real estate | 2021 |
| Flux Padel Ltd | Arts & recreation | 2025 |
| Flux Studios Limited | Arts & recreation | 2016 |
| Flux Verification Ltd | Construction | 2026 |
| Flvr Lounge Ltd | Hospitality | 2025 |
| FLY Media Ltd | Professional & scientific | 2013 |
| Flyforsport Ltd | Information & communication | 2025 |
| Flyingbird Limited | Wholesale & retail | 2022 |
| Flyne Ltd | Wholesale & retail | 2025 |
| Flynn and Eley Associates Ltd | Other services | 2009 |
| Flynnhurst Ltd | Hospitality | 2020 |
| Flyparks Liverpool Ltd | Transport & logistics | 2026 |
| Flyusout Ltd | Administrative & support | 2021 |
| FM Builders & Groundwork Contractors Ltd | Construction | 2020 |
| FM Building Support Ltd | Administrative & support | 2026 |
| FM Caffe Ltd | Hospitality | 2024 |
| FM Cleaning Limited | Administrative & support | 2012 |
| FM Investment & Prop Co Ltd | Real estate | 2019 |
| FM Living Limited | Real estate | 2018 |
| FM Team Ltd | Administrative & support | 2025 |
| FMCK9 Limited | Administrative & support | 2025 |
| Fmfl Limited | Administrative & support | 2024 |
| FMG Productions Ltd | Professional & scientific | 2021 |