| Firgate Limited | Wholesale & retail | 1977 |
| First Breakthrough C.I.C. | Administrative & support | 2018 |
| First Call Healthcare Limited | Health & social care | 2004 |
| First Choice Co. Limited | Real estate | 2019 |
| First Choice Co. Property Ltd | Real estate | 2022 |
| First Class Barber (NE) Limited | Other services | 2025 |
| First Class Distribution NE Ltd | Professional & scientific | 2024 |
| First Concept Communications Partners Limited | Information & communication | 2009 |
| First Face to Face Ltd | Education | 2014 |
| First Finance Commercial Ltd | Financial services | 2024 |
| First FIX Management Limited | Professional & scientific | 2009 |
| First FIX Plastics Ltd | Wholesale & retail | 2009 |
| First Quote Pallets Ltd | Manufacturing | 2009 |
| Firstlite (UK) Limited | Wholesale & retail | 2011 |
| Firtown Ltd | Construction | 2008 |
| Firwood Training Services Ltd | Education | 2019 |
| Fish (LOW Fell) Ltd | Wholesale & retail | 2022 |
| Fish Bar (Gateshead) Ltd | Hospitality | 2024 |
| Fish Bar North East Ltd | Hospitality | 2026 |
| Fish FRY (Sheriff Hill) Ltd | Hospitality | 2017 |
| Fisherwell K9 Security Ltd | Administrative & support | 2026 |
| Fitbook Ltd | Other services | 2019 |
| Fitch Finance Ltd | Financial services | 2015 |
| Fitness Project North East Ltd | Arts & recreation | 2019 |
| Fittreatsuk Ltd | Wholesale & retail | 2026 |
| Five C'S Holdings Ltd | Financial services | 2026 |
| Five Consulting (NE) Limited | Real estate | 2022 |
| Five Star Auto Shine Ltd | Transport & logistics | 2021 |
| Five Wells Limited | Real estate | 2017 |
| Fizza Medics Ltd | Health & social care | 2015 |
| Fizzah ZIA Ltd | Wholesale & retail | 2025 |
| Flame Block Ltd | Administrative & support | 2021 |
| Flash Photography NE Ltd | Professional & scientific | 2024 |
| Flavours (NE) Limited | Hospitality | 2022 |
| Flavourz NE Limited | Hospitality | 2025 |
| Fletcher + Co Consultancy Limited | Professional & scientific | 2025 |
| Fletcher Technical Ltd | Professional & scientific | 2021 |
| Flexinest Properties Ltd | Real estate | 2025 |
| Flight Electrics Ltd | Construction | 2021 |
| Flight Inn Travel Ltd | Administrative & support | 2019 |
| Flip Locations Ltd | Real estate | 2026 |
| Floor.Co (NE) Limited | Wholesale & retail | 2016 |
| Flooring & Cladding Centre Ltd | Construction | 2022 |
| Floorsandology Ltd | Construction | 2022 |
| Floorstyles Bensham Limited | Construction | 2019 |
| Flora North Limited | Wholesale & retail | 2022 |
| Flourishing Language Solution Ltd | Professional & scientific | 2019 |
| Flow Free Power Ltd | Manufacturing | 2020 |
| Flower Nails Ltd | Other services | 2016 |
| Flowers in Fulwell Limited | Wholesale & retail | 2011 |
| Flowing Asbestos Services Limited | Construction | 2024 |
| Flowing Construction Services Limited | Construction | 2018 |
| Flowing Energy Solutions Limited | Construction | 2022 |
| Fluencers Group Ltd | Other services | 2020 |
| Fluffy Frenchie Limited | Other services | 2023 |
| Fluid Automation Limited | Manufacturing | 1994 |
| Fluid Detailing and Valeting Ltd | Wholesale & retail | 2018 |
| Fluid Print Limited | Manufacturing | 2011 |
| FM City Group Ltd | Real estate | 2021 |
| FM West END Ltd | Real estate | 2021 |
| Focus Electrical Installations Limited | Construction | 2019 |
| Fogg of WAR Miniatures Limited | Manufacturing | 2016 |
| Foley Services Ltd | Professional & scientific | 2015 |
| Fontmerry Ltd | Real estate | 2003 |
| Food Frost Ltd | Wholesale & retail | 2018 |
| Food Solution Experts Ltd | Hospitality | 2026 |
| Food Truck Ltd | Hospitality | 2021 |
| Foot Medic LOW Fell Ltd | Health & social care | 2025 |
| FOR the Love of Catering Limited | Hospitality | 2026 |
| FOR the Love of Entertainment Limited | Arts & recreation | 2024 |
| Fora Nature Ltd | Arts & recreation | 2017 |
| Forben Limited | Administrative & support | 2017 |
| Forbes Finance Ltd | | 2010 |
| Fordinghall Ltd | Real estate | 2003 |
| Forense Ltd | Extraterritorial | 2003 |
| Forever Alive Limited | Wholesale & retail | 2023 |
| Forever Yang Ltd | Arts & recreation | 2019 |
| Forgotten North Gaming Limited | Arts & recreation | 2026 |
| Forklift Solutions Limited | Administrative & support | 2003 |
| Formax Medical Services Limited | Health & social care | 2016 |
| Forst Commercial Limited | Professional & scientific | 2024 |
| Forster Pipe Fitting Ltd | Construction | 2013 |
| Forsyth Property Ltd | Hospitality | 2023 |
| Forth Street Fish and Chips Ltd | Hospitality | 2021 |
| Fortitude Promotions Ltd | Arts & recreation | 2023 |
| Fortune Apartments Ltd | Real estate | 2023 |
| Forvena Ltd | Information & communication | 2025 |
| Forward Design Innovation Ltd | Professional & scientific | 2013 |
| FOS Technology UK Ltd | Energy | 2024 |
| Fosh Limited | Wholesale & retail | 2017 |
| Foundations Furniture and Gardening Project Limited | Other services | 1999 |
| Four East Ltd | Households | 2019 |
| Four Oaks Cottage Ltd | Real estate | 2021 |
| Four Oaks Family House Ltd | Real estate | 2020 |
| Fourfolds Grace Ltd | Health & social care | 2025 |
| Foxhound Welfare UK Ltd | Agriculture & fishing | 2025 |
| Foxvar Ltd | Wholesale & retail | 2020 |
| Foxy Hair Extensions (NE) Ltd | Wholesale & retail | 2012 |
| FR Lumley Ltd | Hospitality | 2024 |
| FRA Surveys Limited | Professional & scientific | 2026 |