| Filo PUB Co Limited | Hospitality | 2011 |
| Filtration Control Ltd. | Manufacturing | 1990 |
| Final Driving School Ltd | Education | 2024 |
| Final Five Global Limited | Professional & scientific | 2022 |
| Finance & Accounting for Business Ltd | Administrative & support | 2013 |
| Finance Investments Limited | Financial services | 1995 |
| Finance OPS Solutions Ltd | Professional & scientific | 2026 |
| Finance Recruitment Solutions Ltd | Administrative & support | 2004 |
| Financial Risk Consultants Limited | Financial services | 1988 |
| Fincaro Compliance Services Ltd | Information & communication | 2025 |
| Fincaro OS Ltd | Information & communication | 2026 |
| Finch Electrical Limited | Manufacturing | 2011 |
| Finch Surgical Ltd | Health & social care | 2022 |
| Find the Light Becky Barron Limited | Other services | 2021 |
| Findata Ltd | Information & communication | 2018 |
| Finding Positive Pathways Limited | Health & social care | 2024 |
| Findlays Hairdressing Ltd | Other services | 2007 |
| Findley House Limited | Manufacturing | 1998 |
| Fine & Insight Ltd | Professional & scientific | 2019 |
| Fine CUT Bespoke Limited | Construction | 2023 |
| Fine D.Tail Tattoo Ltd | Other services | 2017 |
| Fine Lady Bakeries Limited | Manufacturing | 1948 |
| Fine Living Homes Limited | Construction | 2021 |
| Fine Resources Limited | Construction | 2015 |
| Fine White Line Limited | Professional & scientific | 2000 |
| Finedon Bulk Haulage Limited | Transport & logistics | 1996 |
| Finedon Hall (Management) Limited | Households | 1993 |
| Fineline Decorating Limited | Construction | 2023 |
| Finesse Protection Ltd | Financial services | 2019 |
| Finest Cuisine Ltd | Hospitality | 2026 |
| Finest Floors Limited | Construction | 2019 |
| Fineworks Ltd | Construction | 2026 |
| Finta Building Services Limited | Construction | 2006 |
| Fiona Marshall Swimtime Limited | Arts & recreation | 2019 |
| FIR Tree Cottage Ltd | Households | 2017 |
| Fire and Safety Assessments Limited | Professional & scientific | 2016 |
| Fire Control Systems Limited | Professional & scientific | 2009 |
| Fire in the Booth Records Limited | Information & communication | 2026 |
| Fire Save Limited | Extraterritorial | 2000 |
| Fire Stopping Surveyors Ltd | Professional & scientific | 2023 |
| Firebrand Consulting Limited | Professional & scientific | 2025 |
| Firestacklabs Ltd | Information & communication | 2026 |
| Firetribe Holdings Limited | Financial services | 2017 |
| Firetribe Productions Limited | Information & communication | 2018 |
| Firetribe Ventures Limited | Administrative & support | 2018 |
| Firgarth Flats (Windermere) Limited | Hospitality | 1994 |
| Firm Anchored Limited | Health & social care | 2025 |
| Firma Fitness Limited | Wholesale & retail | 2020 |
| Firmed Property Investments Ltd | Real estate | 2019 |
| First Choice Mediation Ltd | Professional & scientific | 2013 |
| First Choice Mortgage & Protection Limited | Financial services | 2013 |
| First Choice Textiles Limited | Other services | 2019 |
| First Class Chauffeuring Limited | Transport & logistics | 2026 |
| First Class Timber Ltd | Agriculture & fishing | 2019 |
| First CUT Music Limited | Arts & recreation | 2011 |
| First Eleven Consultancy Ltd | Professional & scientific | 2025 |
| First Five Limited | Manufacturing | 1997 |
| First for Childcare 2 Limited | Financial services | 2014 |
| First for Childcare 3 Limited | Education | 2016 |
| First for Childcare Limited | Education | 2010 |
| First for Engagement Limited | Professional & scientific | 2024 |
| First Freight Ltd | Transport & logistics | 2025 |
| First Glimpse Limited | Other services | 2020 |
| First Impression Training Ltd | Administrative & support | 2001 |
| First Impressions Aqua Clean Ltd | Construction | 2026 |
| First in Events Limited | Arts & recreation | 2020 |
| First Line Medical Ltd | Public administration | 2021 |
| First Rate Recruit Limited | Administrative & support | 2014 |
| First Step Ride Limited | Transport & logistics | 2025 |
| First Steps Property Limited | Real estate | 2006 |
| First Support Services Ltd | Transport & logistics | 2025 |
| FIRST4LEARNING Ltd | Education | 2013 |
| Firsthome Estates Limited | Real estate | 2006 |
| Firstline Communications Limited | Information & communication | 2016 |
| Firtitudo Limited | Financial services | 2016 |
| Fiscal Value Limited | Professional & scientific | 2021 |
| Fish 88 Limited | Hospitality | 2023 |
| Fish and Pond Centre Limited | Agriculture & fishing | 2001 |
| Fish ST Phones Ltd | Wholesale & retail | 2024 |
| Fisher & Paykel Appliances Limited | Wholesale & retail | 2000 |
| Fishing 4 Chips Ltd | Arts & recreation | 2023 |
| Fishon Gear Ltd | Wholesale & retail | 2025 |
| Fisstop Consults Ltd | Information & communication | 2025 |
| Fisstop Investments Ltd | Financial services | 2022 |
| Fit BIZ Marketing Limited | Administrative & support | 2016 |
| Fit Kitchen Eastcheap Limited | Hospitality | 2022 |
| Fit LAB Nutrition Limited | Arts & recreation | 2025 |
| FIT2FUNCTION Clinic Northampton Ltd | Other services | 2025 |
| FIT4TALENT Limited | Administrative & support | 2011 |
| FIT7 Ltd | Wholesale & retail | 2025 |
| Fitness Inc (Weston Favell) Limited | Wholesale & retail | 2018 |
| Fitskincare Limited | Wholesale & retail | 2011 |
| Fitter Body Franchising Limited | Administrative & support | 2017 |
| Fitter Body Ladies Holcot Ltd | Arts & recreation | 2026 |
| Fitter Body Merchandising Ltd | Wholesale & retail | 2018 |
| Fitzroywellington Ltd | Professional & scientific | 2014 |
| Fitzwilliam Place (Lincoln) RTM Company Limited | Households | 2023 |
| Fitzysrus Ltd | Wholesale & retail | 2010 |
| Five 11 Marketing Limited | Administrative & support | 2017 |
| Five Bells Bugbrooke Ltd | Hospitality | 2025 |