| Flow Balance Ltd | Wholesale & retail | 2024 |
| Flow Control Company Limited | Manufacturing | 1991 |
| Flow Control Group Limited | Manufacturing | 2018 |
| Flow Digital Solutions Limited | Information & communication | 2019 |
| Flow Motors Ltd | Wholesale & retail | 2019 |
| Flow Office Limited | Wholesale & retail | 2016 |
| Flow Property Assets Ltd | Real estate | 2020 |
| Flow Property Holdings Ltd | Real estate | 2020 |
| Flow Property Ltd | Professional & scientific | 2019 |
| Flow Studios Audio Post Ltd | Information & communication | 2015 |
| Flowcore MEP Ltd | Construction | 2026 |
| Flower Project Ltd | Wholesale & retail | 2017 |
| Flower Shop (Birmingham) Limited | Wholesale & retail | 2007 |
| Flowerbell Limited | Real estate | 2013 |
| Flowers by Distinction Ltd | Wholesale & retail | 2025 |
| Flowers by M Ltd | Wholesale & retail | 2025 |
| Flowers Investments (Midlands) Limited | Real estate | 2022 |
| Flowers Landscape and Driveways Limited | Administrative & support | 2023 |
| Flowers Landscape Gardening Limited | Administrative & support | 2015 |
| Flowerwalls Ltd | Wholesale & retail | 2022 |
| Flowing Screeds Association Ltd | Other services | 2023 |
| Flowline Trade Ltd | Wholesale & retail | 2025 |
| Flowrish Health Limited | Health & social care | 2023 |
| Flowsave Limited | Manufacturing | 2010 |
| Flowstate Clothing Ltd | Manufacturing | 2023 |
| Flowtastic Payroll Solutions Ltd | Administrative & support | 2025 |
| FLR Wholesale Limited | Wholesale & retail | 2018 |
| FLT UK Training Limited | Education | 2019 |
| Fluent Direct Marketing Limited | Professional & scientific | 2015 |
| Fluffy Duck Games Ltd | Information & communication | 2026 |
| Fluffy Monster Books Ltd | Information & communication | 2023 |
| Fluffycritters Ltd | Wholesale & retail | 2025 |
| Fluid Digital Media Limited | Information & communication | 2012 |
| Fluid Dynamiks Bars Ltd | Hospitality | 2023 |
| Fluid Graphic Designs Limited | Arts & recreation | 1995 |
| Fluid ID Systems Limited | Extraterritorial | 2019 |
| Fluid Risk Consulting Services Ltd | Professional & scientific | 2024 |
| Fluid Solve Ltd | Professional & scientific | 2015 |
| Fluid-E-Motion Ltd | Transport & logistics | 2018 |
| Fluktertone Ltd | Administrative & support | 2021 |
| Flush Fitting Limited | Water & waste | 2016 |
| Flush Windows Direct Ltd | Construction | 2024 |
| Flustra Factor Ltd | Professional & scientific | 2024 |
| Flutter Entertainment UK Limited | Administrative & support | 2024 |
| Flutter Services UK Limited | Administrative & support | 2024 |
| Fluttering Sound Trade Ltd | Wholesale & retail | 2024 |
| Flux Ecom Limited | Wholesale & retail | 2026 |
| Flux Industries Ltd | Manufacturing | 2019 |
| Flux Learning Ltd | Information & communication | 2026 |
| Flux Pavilion Ltd | Administrative & support | 2011 |
| Flux Undies Ltd | Manufacturing | 2018 |
| Flux Vibe Limited | Other services | 2024 |
| Fluxhaven Ltd | Wholesale & retail | 2024 |
| Fluxor Ltd | Hospitality | 2025 |
| Fluxor Software Limited | Information & communication | 2026 |
| Fluxora Energy Ltd | Professional & scientific | 2025 |
| Fluxora Media Ltd | Wholesale & retail | 2026 |
| Fluxtrade Ltd | Wholesale & retail | 2025 |
| Flxunt Ltd | Hospitality | 2023 |
| FLY 27 Limited | Financial services | 2016 |
| FLY Above Aviation Ltd | Transport & logistics | 2004 |
| FLY by Wire Electrical Services Ltd | Professional & scientific | 2021 |
| FLY Education Service Ltd | Education | 2023 |
| FLY Five Star Services Ltd | Administrative & support | 2024 |
| FLY Flamingo Ltd | Administrative & support | 2025 |
| FLY Global International Limited | Wholesale & retail | 2018 |
| FLY Logistics Limited | Wholesale & retail | 2017 |
| FLY Together Careerwise Education Ltd | Hospitality | 2023 |
| Flycrown Travels Limited | Administrative & support | 2026 |
| Flydocs Systems (Midco) Limited | Professional & scientific | 2014 |
| Flydocs Systems (Topco) Limited | Professional & scientific | 2014 |
| Flydocs Systems Limited | Financial services | 2012 |
| Flyerworks Ltd | Manufacturing | 2026 |
| Flygen Limited | Information & communication | 2026 |
| Flygirls Hair and Beauty Limited | Other services | 2018 |
| Flygo Travel & Tourism Ltd | Administrative & support | 2025 |
| Flygun Creative Limited | Administrative & support | 2017 |
| Flying Car Limited | Administrative & support | 2009 |
| Flying Horse Leicester Ltd | Hospitality | 2019 |
| Flying World Travel Ltd | Administrative & support | 2026 |
| Flykicks Ltd | Wholesale & retail | 2026 |
| Flylo Ltd | Wholesale & retail | 2026 |
| Flynews Ltd | Extraterritorial | 2016 |
| Flynn Installations Ltd | Manufacturing | 2025 |
| Flyover Property Investment Limited | Real estate | 2020 |
| Flysmartdirect Limited | Administrative & support | 2025 |
| Flythisgyro Limited | Education | 2008 |
| Flytips by Kartier Ltd | Other services | 2024 |
| Flyway Limited | Transport & logistics | 2025 |
| Flywell Services (UK) Limited | Transport & logistics | 2005 |
| Flywise Aviation Consultancy and Services Ltd | Wholesale & retail | 2024 |
| FM & SA Properties Ltd | Real estate | 2024 |
| FM Connect Network Ltd | Professional & scientific | 2022 |
| FM Corporations Ltd | Real estate | 2020 |
| FM Couriers Ltd | Transport & logistics | 2025 |
| FM Medical Ltd | Extraterritorial | 2023 |
| FM One Event Services Ltd | Administrative & support | 2025 |
| FM Safety Consultancy Services Limited | Professional & scientific | 2012 |
| FM Swinton Limited | Hospitality | 2024 |
| FM Vehicle Solutions Ltd | Wholesale & retail | 2022 |