| Flow UX Limited | Administrative & support | 2013 |
| Flowers Academia Limited | Extraterritorial | 2020 |
| Floyd Building Services Ltd | Construction | 2013 |
| Fluid Systems Exeter Limited | Manufacturing | 2023 |
| Fluid Systems Plymouth Limited | Manufacturing | 2023 |
| FLY Free Group Limited | Financial services | 2017 |
| Flying Bull Properties Limited | Construction | 2024 |
| Flyportscars Limited | Transport & logistics | 2026 |
| Fmdc Real Estate Limited | Real estate | 2021 |
| Fmpmconsultancy Ltd | Wholesale & retail | 2025 |
| FNM Logistics Ltd | Transport & logistics | 2018 |
| Focus Groundworks (Southern) Limited | Construction | 2015 |
| Focused Distribution Ltd | Transport & logistics | 2016 |
| Focusfix Ltd | Construction | 2017 |
| Folio Ideas Limited | Professional & scientific | 2017 |
| Fone Case Limited | Wholesale & retail | 2016 |
| Fontana Capital Ltd | Real estate | 2021 |
| Food 4 Events Limited | Hospitality | 2021 |
| Food 4 U (Portsmouth) Limited | Wholesale & retail | 2016 |
| Food Processing Industries Holdings Ltd | Financial services | 2024 |
| Food Safety Guardians Limited | Administrative & support | 2016 |
| Foody Express Ltd | Hospitality | 2025 |
| Forbes Court, Portsmouth Right to Manage Company Limited | Real estate | 2022 |
| Force Dredging Systems U.K. Limited | Administrative & support | 1997 |
| Force in the Community Ltd | Education | 2025 |
| Ford Lane Property Services Limited | Real estate | 2018 |
| Fore Business Events Ltd | Other services | 2015 |
| Fore Business Limited | Other services | 2013 |
| Forensic Psychology Sussex Limited | Other services | 2017 |
| Foreshore HR Ltd | Administrative & support | 2019 |
| Forever Together Funeral Care (Drayton) Ltd | Other services | 2019 |
| Forever Together Funeral Care (Paulsgrove) Ltd | Other services | 2020 |
| Forever Together Funeral Care Ltd | Other services | 2015 |
| Forgmac Limited | Construction | 2014 |
| Forman Stacy Properties Limited | Construction | 1946 |
| Fort Digital Ltd | Information & communication | 2018 |
| Fort Holdings Ltd | Financial services | 2020 |
| Fortis Holdings Ltd | Professional & scientific | 2014 |
| Fortitude Health Ltd | Arts & recreation | 2019 |
| Fortune Express Ltd | Transport & logistics | 2025 |
| Fortune House Drayton Ltd | Hospitality | 2020 |
| Fortune Securities Limited | Real estate | 2023 |
| Fortysevenpercent Ltd | Professional & scientific | 2019 |
| Forward Control (UK) Limited | Administrative & support | 2003 |
| Fosters Consultants Ltd | Professional & scientific | 2021 |
| Fosters GAS & Heating Ltd | Construction | 2014 |
| Fotherby House RTM Company Limited | Households | 2008 |
| Foudroyant Trust(The) | Manufacturing | 1959 |
| Found Interesting Ltd | Information & communication | 2025 |
| Foundation of Truth Assembly | Other services | 2024 |
| Four Seasons Scaffolding Ltd | Construction | 2018 |
| Four Sided Circle Limited | Financial services | 2017 |
| Fourdeez Ltd | Professional & scientific | 2025 |
| Fourtaps Ltd | Information & communication | 2012 |
| FOX & Bear Property Ltd | Real estate | 2019 |
| FOX Realty Limited | Real estate | 2020 |
| FOX Tail Enterprises Limited | Hospitality | 2022 |
| FOX Utilities Ltd | Construction | 2017 |
| Foxbury Properties Ltd | Real estate | 2025 |
| Foxtrot Developments Ltd | Real estate | 2021 |
| Foxtrot Freehold Ltd | Households | 2024 |
| Foxy Tech Limited | Information & communication | 2014 |
| Foxy's Emporium Ltd | Wholesale & retail | 2025 |
| Foxy's Investments Ltd | Real estate | 2026 |
| FPM Services Ltd | Professional & scientific | 2022 |
| FR Property Group Ltd | Real estate | 2026 |
| Fragrance Exclusive Ltd | Wholesale & retail | 2025 |
| Frame Coat Limited | Extraterritorial | 2019 |
| Franchise Marketing Limited | Arts & recreation | 1988 |
| Francis (Southern) Limited | Construction | 1993 |
| Francis Properties Limited | Construction | 2004 |
| Frank James Court Management Ltd | Real estate | 2025 |
| Franklin Louise Limited | Real estate | 2019 |
| Fratton Autocentre Ltd | Wholesale & retail | 2023 |
| Fratton Car Centre Ltd | Wholesale & retail | 2014 |
| Fratton Cars Ltd | Administrative & support | 2018 |
| Fratton Fade Ltd | Other services | 2025 |
| Fratton Food Store Ltd | Wholesale & retail | 2021 |
| Fratton Hand Car Wash Ltd | Other services | 2022 |
| Fratton Kebab Limited | Hospitality | 2023 |
| Fratton Mobile Shop Ltd | Other services | 2025 |
| Fratton Place Limited | Real estate | 2015 |
| Fratton Services Ltd | Transport & logistics | 2021 |
| Fratton Together CIC | Wholesale & retail | 2024 |
| Fratton Travel Limited | Administrative & support | 2019 |
| Free Flow Portsmouth CIC | Health & social care | 2024 |
| Free Your Voice With Love Ltd | Arts & recreation | 2024 |
| Freedom Friday Limited | Administrative & support | 2016 |
| Freelance SC Limited | Construction | 2019 |
| Freelance Site Services Limited | Construction | 2002 |
| Freeman's Amusements Ltd | Arts & recreation | 2024 |
| Freemantle Services Limited | Wholesale & retail | 2006 |
| Freight Transport Limited | Transport & logistics | 1988 |
| Freightgo Limited | Transport & logistics | 2021 |
| Fremontfm Ltd | Households | 2019 |
| Fresh Digital Agency Ltd | Wholesale & retail | 2019 |
| Fresh Front Exterior Solutions Limited | Administrative & support | 2025 |
| Fresh Halal Meat Portsmouth Ltd | Wholesale & retail | 2025 |
| Fresh Start Clothing Ltd | Wholesale & retail | 2016 |
| Fresh Start Psychological Services Ltd | Health & social care | 2019 |