| First Strategy Financial Services Ltd | St Albans | A rating |
| First Subsea Limited | Lancaster | A rating |
| First Technology Holdings Ltd | Reading | A rating |
| First Thought Care Services | Gloucester | A rating |
| FIRST TONE LTD | London | A rating |
| First TransPennine Express | Manchester | A rating |
| FIRST TRENITALIA WEST COAST RAIL LIMITED (T/A AVANTI WEST COAST) | London | A rating |
| FIRST TRUCK & VAN SERVICES LIMITED | GLASGOW | A rating |
| First Trust Global Portfolios Ltd. | London | A rating |
| First Tutors HM Limited | London | A rating |
| First Tutors UK | London | A rating |
| FIRST UK | London | A rating |
| First UK Security Services Limited | Oldham | A rating |
| First Underwriting Limited | London | A rating |
| First Up, S.L.U t/a Master Stonemasons (UK establishment) | Sutton Coldfield | A rating |
| First Water Ramsbury Limited | Malborough | A rating |
| FIRST WEALTH MANAGEMENT LIMITED | London | A rating |
| FIRST WITHIN LIMITED | Croydon | A rating |
| First Years Childcare Limited t/a Banana Moon | London | A rating |
| First-Step Group Limited | Manchester | A rating |
| First-String Homes Limited | London | A rating |
| FirstBank UK Limited | London | A rating |
| FIRSTCALL 247 LIMITED | Nottingham, | A rating |
| FirstCare (GB) Ltd | Bedford | A rating |
| Firstcare (Mansfield) Limited | Derby | A rating |
| Firstcare Practice | Birmingham | A rating |
| Firstcare Practice | Hounslow | A rating |
| Firstcare Solutions ltd | Falkirk | A rating |
| Firstchoice Consultancy Ltd | Dagenham | A rating |
| Firstclass Managerial Limited | Ashton-Under-Lyne | A rating |
| FirstClass Safety and Control Ltd | Colchester | A rating |
| Firstco Limited | London | A rating |
| FirstCol Services Ltd | Crawley | A rating |
| Firstline Pharma Ltd | Hemel Hempstead | A rating |
| FIRSTLINE SECURITY SERVICES LIMITED | Reading | A rating |
| FirstMind Ltd | London | A rating |
| firstminute capital LLP | LONDON | A rating |
| Firstpoint Homecare Ltd | Manchester | A rating |
| FirstRand Bank Ltd (London Branch) | London | A rating |
| Firstsmile Limited | Brent Street | A rating |
| Firstsource Solutions UK Limited | London | A rating |
| FIRSTSTEP CARE LIMITED | LONDON | A rating |
| Firstup UK Limited | London | A rating |
| FirstVet UK Ltd | London | A rating |
| Firstware Ltd | Northampton | A rating |
| Firsway Health Centre | Sale | A rating |
| Firth Firth and Smith Limited | WARRINGTON | A rating |
| Firvale Community Hub | Sheffield | A rating |
| Firwood Bootle Cricket Club | Bootle | A rating |
| FIS Capital Markets UK Limited | London | A rating |
| FIS SUPPLIERS LIMITED | Birmingham | A rating |
| Fiscal Knights Accountants Ltd | Birmingham | A rating |
| FISCAL WISE SOLUTIONS LIMITED | Ilford | A rating |
| Fiscalculate Ltd T/A BCM Accountants | Manchester | A rating |
| Fischer Farms Ltd | Barton under Needwood | A rating |
| fischer fixings UK Ltd | Wallingford | A rating |
| Fischer Future Heat UK Ltd | Leicester | A rating |
| FISCO (UK) Limited | Wokingham | A rating |
| Fiserv (Europe) Ltd. | Basildon | A rating |
| Fish & Chicken Bar Limited t/a Fist & Chicken Bar & Curry Club | Tain | A rating |
| Fish Boat Ltd t/a Bodrum | Glenrothes | A rating |
| FISH FACE LONDON LIMITED | London | A rating |
| Fish House Restaurant | London | A rating |
| fish in a bottle limited | Warwick | A rating |
| FISH TO HOME LIMITED | Swindon | A rating |
| FISH UNION LTD | Chislehurst | A rating |
| Fish White Ltd T/A White Fish | London | A rating |
| Fishbourne Nursing Home | Ballynahinch | A rating |
| FISHBURN CONVENIENCE STORE LTD | Ferryhill | A rating |
| Fisher & Donaldson (St Andrews) Ltd | Cupar | A rating |
| Fisher & Paykel Appliances Limited | Northampton | A rating |
| Fisher and Paykel Healthcare Limited | Maidenhead | A rating |
| FISHER CARE GROUP | Newcastle upon Tyne | B rating |
| Fisher Financial Advisors Ltd | Wallington | A rating |
| Fisher Investments Europe Limited | London | A rating |
| Fisherbell Ltd | Sheffield | A rating |
| FISHERDAY SOLICITORS | CHESHIRE | A rating |
| Fishergate Primary School | York | A rating |
| Fisherman Catch Limited | SHEERNESS | A rating |
| Fisherrow Stores Limited | Musselburgh | A rating |
| Fishers Green Convenience Store | Stevenage | A rating |
| Fisherton Dental Care | Salisbury | A rating |
| Fishes Royale Limited t/a Lilibets | London | A rating |
| Fishfinger Media Ltd | London | A rating |
| Fishgate Consulting Limited | Kent | A rating |
| Fishguard Veterinary Services Ltd | Fishguard | A rating |
| FISHNET (LONDON) LTD | London | A rating |
| Fishouse (Oban) Ltd | Oban | A rating |
| Fishpool News Limited | Bury | A rating |
| Fishpools Ltd | Waltham Cross | A rating |
| Fishveg Ltd | Taplow | A rating |
| Fisk & Osbourne Building Limited | Stanford le Hope | A rating |
| Fisk Fire Protection Ltd | Chelmsford | A rating |
| Fiskars UK Limited | Stoke on Trent | A rating |
| Fiskens | London | A rating |
| Fission Care Ltd | London | A rating |
| Fit Out (UK) | London | A rating |
| FIT SHIRTS LTD | London | A rating |
| Fitch Ratings Limited | London | A rating |
| FitFactory Innovations Ltd | Warrington | A rating |
| FITFILE Group Limited | London | A rating |
| FITFITSHOP LTD | Caerphilly | A rating |
| Fitflop Ltd | London | A rating |
| FITMINDS STRATEGY CONSULTING LTD | London | A rating |
| Fitness Business Profits | Worthing | A rating |
| Fitness HQ Limited | London | A rating |
| Fitness Online Direct Ltd | Huddersfield | A rating |
| Fitness Regime Ltd T/A Sparta Warrior | Oldham | A rating |
| FitnessGenes Ltd | Bicester | A rating |
| FITnFIX Ltd | Beckenham | A rating |
| Fitou Limited | London | A rating |
| FITPRO-X LIMITED | Newcastle Upon Tyne | A rating |
| FITRADE PARTNERS LTD (GB) (12493307) | London | A rating |
| Fitted Home Alarms Ltd | High Wycombe | A rating |
| Fitted Wardrobes Ltd | Hayes | A rating |
| Fitter feet for Life | London | A rating |
| FITTING NAILS LIMITED Trading as Creative Nails Cambridge | Cambridge | A rating |
| Fitton Hill Post Office | Oldham | A rating |
| FITTRA LTD | London | A rating |
| FitXR Limited | London | A rating |
| Fitz Partners Limited | London | A rating |
| Fitzalan Medical Centre | Littlehampton | A rating |
| FITZARTHUR AUTOMOTIVE LTD | London | A rating |
| Fitzgerald Plant Services Ltd | Cwmbran | A rating |
| Fitzpatrick Construction UK Limited | London | A rating |
| Fitzpatrick Referrals Ltd | Godalming | A rating |
| Fitzrovia Trading Limited | London | A rating |
| FITZROY LODGE | WORTHING | A rating |
| Fitzroy Motor Co Ltd | Ringwood | A rating |
| FitzRoy Support | Petersfield | A rating |
| FitzWalter Capital Limited | London | A rating |
| Fitzwilliam College in the University of Cambridge | Cambridge | A rating |
| FIVE 9S SOLUTIONS LTD | Milton Keynes | A rating |
| FIVE AI Limited | Cambridge | A rating |
| Five Akhis Luton | Luton | A rating |
| Five Alarm Bio Ltd | Hauxton | A rating |
| Five Alls Management Ltd | Cheltenham | A rating |
| Five Bells Bugbrooke Ltd TAs Five Bells | Bugbrooke | A rating |
| Five Bros & Co Limited | Romford | A rating |
| Five Fifty Five Productions Limited | London | A rating |
| Five Fingers Aroma Ltd T/A Five Fingers Finest Indian Cuisine | London | A rating |
| Five Guys JV LTD | London | A rating |
| Five Health Group Limited | Pinner, | A rating |
| Five Lads Goodmayes | London | A rating |
| Five Mile Films Limited | Bristol | A rating |
| Five Oak Green Pet Surgery Limited | Five Oak Green (Tonbridge) | A rating |
| Five Oceans Spaces Ltd | Doncaster | A rating |
| FIVE ONE TWO (E.M.A.) LIMITED | Derby | A rating |
| Five Rings Capital LLP | London | A rating |
| Five Rise Nursing Home Ltd | Bingley | A rating |
| FIVE RIVER FOODS | Bradford, | A rating |
| Five Rivers Catering Division Limited | Walsall | A rating |
| Five Rivers Dental Ltd | Bognor Regis | A rating |
| Five Rivers Distribution Ltd | Slough | A rating |
| Five Rivers Grill & Restaurant T/A Bhupinder Tamana | London | A rating |
| FIVE RIVERS LEATHERHEAD LTD T/A FIVE RIVERS | Surrey | A rating |
| Five Star Asian Foods Limited T/A Younis Cash and Carry | Manchester | A rating |
| Five Star Auto Salvage Ltd | Elmsett | A rating |
| Five Star Autocentre | Huddersfield | A rating |
| Five Star Convenience Limited | Poole | A rating |
| Five Star Deals UK Limited | Croydon | A rating |
| FIVE STAR ENTERPRISE LIMITED t/a Meriden Post Office | Watford | A rating |
| FIVE STAR FISHERIES LTD | Ilford | A rating |
| Five Star Fresh Ltd | Bradford | A rating |
| FIVE STAR HAIR LIMITED | BRADFORD | A rating |
| FIVE STAR SUPPORT SERVICES LIMITED | Essex | A rating |
| Five StarHunts LTD | Huntingdon | A rating |
| Five Talents UK LTD | London | A rating |
| Five Tech Limited | London | A rating |
| Five Ways Convenience Store | Rotherham | A rating |
| FIVE WAYS DRY CLEANER | BIRMINGHAM | A rating |
| Five9, Inc UK Limited | London | A rating |
| Fivefold Studios Limited | Pencoed | A rating |
| Fiver London Limited | Basildon | A rating |
| FiveRivers Environmental Contracting Ltd | Andover | A rating |
| Fives and Heronians Cricket Club | Chigwell | A rating |
| Fives Bronx Limited | West Midlands | A rating |
| Fives Landis Limited | Keighley | A rating |
| Fives Stein Limited | Didcot | A rating |
| Fivesky Limited | London | A rating |
| Fivestar Catering Limited | London | A rating |
| Fivetran UK Limited | Bristol | A rating |
| Fiveways Convenience Store | Worksop | A rating |
| FIVEWAYS CONVENIENCE STORE | CHESTERFIELD | A rating |
| Fiveways Convenience Store Skellow | Doncaster | A rating |
| FIVEWAYS MOT STATION LTD | MANCHESTER | A rating |
| Fivium Limited | London | A rating |
| FIX FELLA LIMITED | Carrickfergus | A rating |
| FIX PHONE MCR LTD | Bangor | A rating |
| Fix Tech Experts Limited | Hove | A rating |
| FIX&BUILD HOMES LTD | London | A rating |
| FIXA PHONE LIMITED | Bristol | A rating |
| Fixby Healthcare Ltd | Huddersfield | A rating |
| Fixed Ops Ltd t/a Baloci | Birmingham | A rating |
| Fixed Phage Ltd | Glasgow | A rating |
| FIXING POINT LTD | Gloucester | A rating |
| FIXMYBROKENSCREEN.CO.UK LTD | London | A rating |
| FIXTECH LIMITED | London | A rating |
| Fixura Interiors London Ltd. | Uxbridge | A rating |
| Fixxo London Ltd | London | A rating |