| First for Justice Ltd | Professional & scientific | 2023 |
| First Language Ltd | Professional & scientific | 2012 |
| First MED Care Limited | Health & social care | 2021 |
| First Penthouse Limited | Construction | 2006 |
| First Principles Strategy Ltd | Professional & scientific | 2026 |
| First Stop Cleaning Limited | Administrative & support | 2021 |
| First-Rate Maintenance Limited | Construction | 2018 |
| Firstline Security Solutions Limited | Administrative & support | 2025 |
| Firstlinetech Ltd | Information & communication | 2012 |
| Firsttouchfootballcoaching Ltd | Arts & recreation | 2025 |
| Fischer Wolff International Ltd | Administrative & support | 2014 |
| Fish Key North Shields Limited | Real estate | 2026 |
| Fish Quay Leisure Limited | Hospitality | 2019 |
| Fishbone Commercial Properties Ltd | Real estate | 2021 |
| Fishbone Waste Ltd | Water & waste | 2021 |
| Fisher 9 Ltd | Construction | 2020 |
| Fisher Care Bridlington Limited | Health & social care | 2025 |
| Fisher Care Group Limited | Health & social care | 2012 |
| Fisher Care Heywood Limited | Health & social care | 2025 |
| Fisher Care Leeds Limited | Health & social care | 2024 |
| Fisher Hawkes Recruitment Limited | Administrative & support | 2019 |
| Fisher Property and Investments Ltd | Real estate | 2025 |
| Fisher Street Garage Ltd | Wholesale & retail | 2008 |
| Fisherring Holdings Limited | Financial services | 2025 |
| Fishguard CEC Ltd | Health & social care | 2023 |
| Fisica Limited | Financial services | 2000 |
| Fission Properties Limited | Real estate | 2024 |
| Fit Cloud Technology Ltd | Arts & recreation | 2010 |
| Fit Family Sport and Entertainment Ltd | Information & communication | 2020 |
| Fit Training International Limited | Education | 2015 |
| Fit&Co Limited | Real estate | 2017 |
| Fitch Taylor Limited | Real estate | 2009 |
| Fitness Family Global Sports and Entertainment Ltd | Information & communication | 2021 |
| Fitness Fraternity Gym Ltd | Arts & recreation | 2021 |
| Fitness Fraternity Properties Limited | Real estate | 2023 |
| Fitness Skills North East LP | | 2012 |
| Fitness Works NE Ltd | Arts & recreation | 2013 |
| Fitpro-X Limited | Education | 2020 |
| Fitt NE Ltd | Arts & recreation | 2025 |
| Fitz-A-Trick Limited | Health & social care | 2016 |
| Fitzgeralds Motoring Services Ltd | Wholesale & retail | 2019 |
| Fitzpatrick Urology Ltd | Health & social care | 2026 |
| Fitzpatrickroyle (NE) Limited | Financial services | 2016 |
| Fitzpatrickroyle Limited | Professional & scientific | 2012 |
| Fitzwilliam Place Residents Management Company Limited | Real estate | 2026 |
| Fivaj Properties Ltd | Real estate | 2026 |
| Five Bells Pubco Ltd | Hospitality | 2018 |
| Five Mile Park Management Company Limited | Households | 2013 |
| Five Nine Wind Ltd | Construction | 2024 |
| Five Real Estate Ltd | Real estate | 2024 |
| Five Times Five Ltd | Wholesale & retail | 2023 |
| FIVETHREE7 (Northumberland) Limited | Administrative & support | 2018 |
| FIX IT Fit Ltd | Construction | 2023 |
| FIX Mode Auto Services Limited | Wholesale & retail | 2022 |
| FIX Mode Newcastle Limited | Wholesale & retail | 2026 |
| FIX My Boiler Ltd | Construction | 2026 |
| FIX24 Ltd | Information & communication | 2026 |
| Fixalmet Ltd. | Wholesale & retail | 2016 |
| Fixed FEE Accountancy Limited | Professional & scientific | 2010 |
| Fixitcafe CIC | Other services | 2024 |
| Fixtura Limited | Information & communication | 2026 |
| FJ Business Management Limited | Professional & scientific | 2015 |
| FJ Property Maintenance Limited | Extraterritorial | 2009 |
| FJA CAP Limited | Professional & scientific | 2024 |
| Fjord Health Ltd | Wholesale & retail | 2023 |
| Flag C Limited | Professional & scientific | 2011 |
| Flag Hotels Limited | Financial services | 1990 |
| Flaire Consultants Ltd | Education | 2016 |
| Flame N Grill (NE) Ltd | Hospitality | 2019 |
| Flamingo 6 Ltd | Extraterritorial | 2023 |
| Flange Torque Ltd | Professional & scientific | 2025 |
| Flash Electrical U.K. Limited | Construction | 2016 |
| Flash Pods Ltd | Professional & scientific | 2025 |
| Flash Services North East Limited | Administrative & support | 2010 |
| Flat Caps Coffee Ltd | Hospitality | 2016 |
| Flat Services Limited | Households | 1990 |
| Flats.Co.Uk Limited | Real estate | 2006 |
| Flatsnout Boxing Training Limited | Administrative & support | 2020 |
| Flaura Rose Ltd | Wholesale & retail | 2023 |
| Flavoured House Foods Limited | Hospitality | 2019 |
| Flawless Finish Cleaning Services Ltd | Administrative & support | 2025 |
| Flbg LLP | | 2011 |
| Flea Circus Ltd | Wholesale & retail | 2018 |
| Fleet House Management Ltd | Administrative & support | 2011 |
| Fleet Management Ltd | Hospitality | 2023 |
| Fleming Properties (N E) Limited | Real estate | 2024 |
| Flemings Hair and Grooming Ltd | Other services | 2024 |
| Fleur DE K Ltd | Wholesale & retail | 2025 |
| Fleur Maria Properties Ltd | Real estate | 2022 |
| Flexgoo Limited | Wholesale & retail | 2025 |
| Flexha Ltd | Wholesale & retail | 2019 |
| Flexible Support Options (UK North East) Limited | Extraterritorial | 1998 |
| Flexible Support Options Holdings Limited | Professional & scientific | 2012 |
| Flexible Support Options Limited | Health & social care | 2012 |
| Flexigraze CIC | Agriculture & fishing | 2011 |
| Flexistayuk.Com Ltd | Real estate | 2026 |
| Flight Mode Competitions Ltd | Arts & recreation | 2025 |
| Flightblade Limited | Real estate | 2006 |
| Flint Pizza Ltd | Hospitality | 2018 |
| Flint Television Ltd | Information & communication | 2016 |