| Femometer UK Limited | Wholesale & retail | 2022 |
| Fentro CIC | Education | 2025 |
| Ferndale DC Ltd | Health & social care | 2023 |
| Festind International Co., Ltd | Professional & scientific | 2014 |
| Ffaith Marketing Ltd | Professional & scientific | 2023 |
| Fhannah Ltd | Wholesale & retail | 2024 |
| Fibre Components Limited | Manufacturing | 2003 |
| Fidere Fashion Limited | Wholesale & retail | 2020 |
| Fidgeon Property Ltd | Real estate | 2026 |
| Fiesono Industrie Limited | Manufacturing | 2024 |
| Fighting Homelessness CIC | Administrative & support | 2021 |
| Filton Residence Limited | Wholesale & retail | 2024 |
| Finest Saffron Limited | Administrative & support | 2015 |
| Fireform Limited | Administrative & support | 2020 |
| Firestorm Games Limited | Information & communication | 2012 |
| Firmgold Limited | Professional & scientific | 1999 |
| First Response Medical Training Ltd | Professional & scientific | 2020 |
| Firstasher Ltd | Wholesale & retail | 2024 |
| Fit and Well Limited | Arts & recreation | 2014 |
| Fjordstans Ltd | Information & communication | 2019 |
| FJS Consulting Solutions Limited | Professional & scientific | 2025 |
| FJS Properties Ltd | Real estate | 2016 |
| Flame and Go Ltd | Construction | 2020 |
| Flash Communications Limited | Professional & scientific | 2019 |
| FLC Group Ltd | Manufacturing | 2024 |
| Flight Path Live Ltd | Wholesale & retail | 2024 |
| Flocon Group Limited | Financial services | 2026 |
| Flocon Valves & Fittings Limited | Wholesale & retail | 1989 |
| Floor Fitters South Wales Limited | Construction | 2021 |
| Flooring Depot Ltd | Wholesale & retail | 2021 |
| Flowline Civil Engineering Ltd | Construction | 1995 |
| Flush Interior Design & Build Ltd | Construction | 2023 |
| FLY Clouds Trade Ltd | Wholesale & retail | 2024 |
| Flymatecheckin Ltd | Administrative & support | 2026 |
| Focus Collision Investigation Ltd | Professional & scientific | 2017 |
| Focus UP Ltd | Wholesale & retail | 2013 |
| Foleys Five Holding Company Ltd | Financial services | 2022 |
| FONECARE78 Limited | Wholesale & retail | 2023 |
| Forest Park & Garden Ltd | Manufacturing | 2023 |
| Forlega Ltd | Wholesale & retail | 2025 |
| Fortress Estate Agency Limited | Real estate | 2013 |
| Fortress International Property Services Limited | Real estate | 1999 |
| Forward Industry Threads & Training Ltd | Wholesale & retail | 2025 |
| Foulpay Limited | Information & communication | 2026 |
| Foundry DL Limited | Manufacturing | 2025 |
| Four Beere's Ltd | Real estate | 2022 |
| Four Clean Wheels Vehicle Logistics Ltd | Other services | 2014 |
| Four Seasons Catering and Events Limited | Hospitality | 2021 |
| FOX & Field Goods Ltd | Wholesale & retail | 2026 |
| Foxglove Property Investments Limited | Real estate | 2025 |
| FP Leadgen Limited | Professional & scientific | 2019 |
| FPG Training Limited | Professional & scientific | 2025 |
| Frankies Farm Ltd | Other services | 2023 |
| Freestyle Hair Design (Treforest) Limited | Other services | 2005 |
| Fresco Coffee Bar Limited | Hospitality | 2023 |
| Fresh Flow Business Services Ltd | Professional & scientific | 2011 |
| Fresi Chemicals Co., Ltd | Wholesale & retail | 2021 |
| Friends Food Rhydyfelin Ltd | Hospitality | 2026 |
| FRM Roofing Limited | Construction | 2022 |
| FS Property Developments Ltd | Real estate | 2024 |
| FT Technology Co., Ltd | Wholesale & retail | 2013 |
| Fukwai ( Ynysybwl ) Ltd | Hospitality | 2024 |
| FUN Water Technology Ltd | Wholesale & retail | 2024 |
| FUR Squad Limited | Wholesale & retail | 2025 |
| Future Industry Share Limited | Professional & scientific | 2012 |
| Fxcomps Ltd | Wholesale & retail | 2024 |
| G & C Electricals Limited | Construction | 2007 |
| G & E CYF | Real estate | 2026 |
| G & K Interior Specialists Limited | Construction | 2018 |
| G & R Force Security Limited | Administrative & support | 2017 |
| G a I Associates Ltd | Professional & scientific | 2008 |
| G Bridges Welding & Plating Ltd | Manufacturing | 2006 |
| G Comms Electrical Ltd | Construction | 2020 |
| G J Martin Ltd | Professional & scientific | 2019 |
| G P Glass Ltd | Construction | 1999 |
| G P T Builders Limited | Construction | 2017 |
| G S W Construction Limited | Construction | 2015 |
| G Way Solar Panel Services Ltd | Construction | 2026 |
| G&B Decorating Contractors Ltd | Other services | 2017 |
| G&K DE Snyder Ltd | Other services | 2018 |
| G&K Housing Ltd | Real estate | 2024 |
| G. HOW Clean Limited | Water & waste | 2003 |
| G.B. Engineering (Wales) Limited | Manufacturing | 1965 |
| G.H. Griffiths & Sons Limited | Wholesale & retail | 1992 |
| G7 Homes Ltd | Real estate | 2018 |
| GA Express Freight Limited | Transport & logistics | 2026 |
| Gabaet Logistics Limited | Transport & logistics | 2018 |
| Gables Star Properties Ltd | Households | 2012 |
| Gaggi Traders Ltd | Wholesale & retail | 2025 |
| Gaigao Co., Limited | Wholesale & retail | 2024 |
| Gamco Limited | Real estate | 1988 |
| Gareth Lawrence Rail Ltd | Construction | 2017 |
| Garth Building Limited | Construction | 2001 |
| Garth Lights Limited | Wholesale & retail | 2023 |
| Garth Olwg Catering Ltd | Hospitality | 2019 |
| Garth View Ltd | Transport & logistics | 2020 |
| Garyal 1979 Limited | Extraterritorial | 2014 |
| GAS and Plumbing Solutions Ltd | Construction | 2022 |
| GAS Engineer DAN Ltd | Construction | 2025 |
| Gaspack Services Limited | Professional & scientific | 2005 |