| Fire Service College Ltd | Moreton In Marsh | A rating |
| Fire Suppression Technology Ltd | WOKING | A rating |
| FIRE SYSTEMS LTD | KINGSTON UPON THAMES | A rating |
| Fire-serv UK (Midlands ) Ltd | Leicester | A rating |
| FireAngel Safety Technology Limited | Coventry | A rating |
| Fireant Networks Limited | Harlow | A rating |
| Fireantpay (UK) Limited | London | A rating |
| Fireaway (Loughton) Limited | Loughton | A rating |
| FIREAWAY ABERDEEN LIMITED | ABERDEEN | A rating |
| FIREAWAY ASCOT LTD | Ascot | A rating |
| Fireaway Canterbury Ltd | Canterbury | A rating |
| FIREAWAY CRAWLEY LIMITED | Crawley | A rating |
| FIREAWAY DARTFORD LTD | Dartford | A rating |
| Fireaway Leicester Limited | Leicester | A rating |
| FIREAWAY MANCHESTER LTD T/A FIREAWAY DESIGNER PIZZA | Fallowfields, Manchester | A rating |
| Fireaway north west London limited | Kilburn | A rating |
| Fireaway Pizza London Ltd. T/A Fireaway Pizza | London | A rating |
| Fireaway Pizza Ltd | Milton Keynes | A rating |
| FIREAWAY PIZZA PLYMOUTH LTD | London | A rating |
| Fireaway SE Ltd | London | A rating |
| fireaway se18 ltd | london | A rating |
| FIREAWAY SUNBURY-ON-THAMES LTD | Sunbury-on-Thames | A rating |
| Fireaway Tunbridge wells Ltd | Croydon | A rating |
| Fireaway Woking Ltd T/A Fireaway | Surrey | A rating |
| Fireaway Woodhouse Ltd | Mansfield | A rating |
| Fireaway Worcester Limited | Worcester Park | A rating |
| Fireblitz Extinguisher Ltd | Erith | A rating |
| FIREBLOCKS UK INT'L LIMITED | London | A rating |
| Firebrand Training Ltd | London | A rating |
| Firecracker Works Limited | London | A rating |
| Firefinch Software Ltd | Edinburgh | A rating |
| Firefish Limited | London | A rating |
| Firefish Software | Glasgow | A rating |
| Firefly Communications Group Limited | London | A rating |
| FIREFLY ELECTRICS & BUILDERS LTD | Bolton | A rating |
| Firefly London Group ltd | London | A rating |
| Firefly Orthoses NI Limited | Enniskillen | A rating |
| FIREFLYAPPS LIMITED | Staveley | A rating |
| Fireglass Direct Ireland Ltd | Magherafelt | A rating |
| Fireguard Global Ltd | WILLENHALL | A rating |
| FIRELOG LTD | Hayes | A rating |
| Firemate Ltd | Nottingham | A rating |
| Firemind Ltd | Maidstone | A rating |
| FireMon Limited | Warwick | A rating |
| Fireon Ltd | London | A rating |
| Fireproof Studios Limited | London | A rating |
| Firesouls Limited | London | A rating |
| Firespec Ltd | Perth | A rating |
| Firestarter Business Solutions Limited | Cheltenham | A rating |
| FireStone Belfast Ltd | Belfast | A rating |
| Firetail Limited | London | A rating |
| FireTap Ltd | London | A rating |
| Firetech (UK) Limited | Manchester | A rating |
| FiretechZone Ltd | Watford | A rating |
| Firetecnics Systems Limited | London | A rating |
| FIREWOOD INVESTMENT (UK) LTD t/a TOKIA SQUARE | London | A rating |
| Firewood Ltd | London | A rating |
| Firich UK Co., Ltd | London | A rating |
| Firm of Intercontinental Hospitality | Fort William | A rating |
| Firm of Robert Neill | Perth | A rating |
| Firmament Capital Advisors UK LLP | London | A rating |
| Firmdale Hotels PLC | London | A rating |
| Firmenich UK Ltd | Southall | A rating |
| Firmer Terrain Ltd. | Milton Keynes | A rating |
| Firmex International Limited | London | A rating |
| Firmly Medical Ltd | Dagenham | A rating |
| Firn Overseas Packaging Limited | Newbury | A rating |
| Firoka (Kings Cross) Ltd | London | A rating |
| FIRST 2 CARE SERVICE LTD | BEDFORD | A rating |
| First Abu Dhabi Bank P.J.S.C. | London | A rating |
| First Access Entertainment Limited | London | A rating |
| First Active 365 Homecare | Birmingham | A rating |
| First Advantage Europe Ltd | Nottingham | A rating |
| First Alba Healthcare Limited | Dundee | A rating |
| First Allied Facilities Ltd | East Ham | A rating |
| First AML | Shoreditch | A rating |
| First Avenue Partners LLP | London | A rating |
| First Beeline Buses Limited | Slough | A rating |
| First Bridge Group Ltd | London | A rating |
| First British Clinic Limited | London | A rating |
| First Bus Central Services Limited | London | A rating |
| First Business Ltd | Basingstoke | A rating |
| First Call Community Systems Limited | Chester | A rating |
| FIRST CALL MEDWAY LTD | Rainham | A rating |
| First Care Homes Ltd | Great Shelford | A rating |
| First Care Lodge Ltd | London | A rating |
| FIRST CARE PHYSIOTHERAPY AND SPORTS CLINIC LTD | LONDON | A rating |
| First Care Services Limited | Wolverhampton | A rating |
| FIRST CARS READING LTD | READING | A rating |
| FIRST CASTILLA LTD T/A LOBOS MEAT & TAPAS | LONDON | A rating |
| First Central Insurance Management Ltd | Haywards Heath | A rating |
| FIRST CHOICE ALUMINIUM H & P LIMITED | Manchester | A rating |
| FIRST CHOICE BUILDING SERVICES NOTTINGHAM LTD | Nottingham | A rating |
| First Choice Building Supplies Limited | Hayes | A rating |
| First Choice Care Agency Limited | Leicester | A rating |
| First Choice Care Limited | Middlesex | A rating |
| First Choice Care Ltd | Wembley | A rating |
| First Choice Care Services Ltd | London | A rating |
| FIRST CHOICE CONVENIENCE STORE | DERBY | A rating |
| First Choice Dental Clinic | Eastbourne | A rating |
| First Choice Fruit & Vegetable Market | London | A rating |
| FIRST CHOICE HEALTHCARE SERVICES LTD | Coventry | A rating |
| First Choice Home Care Ltd | Snetterton | A rating |
| First Choice Kitchen and Bedroom Limited | Hounslow | A rating |
| First Choice Medical Solutions Ltd | Hertfordshire | A rating |
| FIRST CHOICE OFF LICENSE LTD | Poole | A rating |
| FIRST CHOICE SAFETY TRAINING LTD | London | A rating |
| FIRST CHOICE STORE LTD | Rochdale, England | A rating |
| First Choice Transportation Ltd | London | A rating |
| FIRST CHOICE VEHICLE MANAGEMENT LTD | Barking | A rating |
| First Circle Packaging Limited | Milton Keynes | A rating |
| First Citi CONSULT Ltd | Barnoldswick | A rating |
| First City Nursing Services Limited | Swindon | A rating |
| FIRST CLASS CARS LTD | Surrey | A rating |
| First Class Healthcare Ltd | Chatham | A rating |
| First Class Learning Ltd | Reading | A rating |
| First Class Lighting Limited | Birmingham | A rating |
| First Class Services Group Ltd | Brentford | A rating |
| First Class Supplies UK Ltd | Milton Keynes | A rating |
| First Click Solutions Ltd | Burnley | A rating |
| First Commercial Bank Limited | London | A rating |
| First Community Health and Care | Redhill | A rating |
| FIRST CONNECT HEALTHCARE LTD | London | B rating |
| First Contact Property Services Ltd | London | A rating |
| First Corporate Finance Limited | Harrow | A rating |
| First Credit Advice Limited | Romford | A rating |
| First Day Nursery Ltd | Ilford | A rating |
| FIRST DENTAL | walsall | A rating |
| First Developments Limited T/A The Grapevine | London | A rating |
| First Dispute Management Ltd | Manchester | A rating |
| First Editions Ltd | Birmingham | A rating |
| First Equitable (UK) Ltd | Liverpool | A rating |
| First Fence Ltd | Swadlincote | A rating |
| First Fix Formwork Limited | Stoke-on-Trent | A rating |
| First Force Security Services LTD | Romford | A rating |
| First Friendly Finance Ltd | Manchester | A rating |
| FIRST GEAR CONVENIENCE STORE | LONDON | A rating |
| First Glass London Limited | Southall | A rating |
| First Grade International Ltd | Bromsgrove | A rating |
| First Graphene UK Ltd. | Sedgefield | A rating |
| First Greater Western Ltd | Swindon | A rating |
| First Halal Meat Ltd | Glasgow | A rating |
| First Haul Ltd | Milton Keynes | A rating |
| First Haven Providers Ltd | Salford | A rating |
| First Healthcare Limited | Bradford | A rating |
| FIRST HORIZON SCOTLAND LTD | Fife | A rating |
| First Hydrogen Limited | London | A rating |
| First Import And Export Services Limited | Beckenham | A rating |
| First In Care Services Ltd | Portsmouth | A rating |
| First Integrated Solutions Limited | Aberdeen | A rating |
| First Intuition East and North Limited | Cambridge | A rating |
| First IPC Presbytery of England | Hounslow | A rating |
| FIRST KALMS LIMITED | MIDDLESEX | A rating |
| FIRST KLASS SHIPPING SPECIALIST LTD | Birmingham | A rating |
| FIRST LANDLORD CERTIFICATES LONDON LTD | London | A rating |
| First Lane Education UK Consultancy Ltd | London | A rating |
| First Law Solicitors Limited | Manchester | A rating |
| First Light Fusion Limited | Kidlington | A rating |
| First Light Games Ltd | Canterbury | A rating |
| First Line Cars Ltd. | Reading | A rating |
| First Line Physio | Cheltenham | A rating |
| First London Property Management Limited | Middlesex | A rating |
| First Marine Solutions Limited | Aberdeen | A rating |
| First Marketing Ltd | London | A rating |
| FIRST MEDICAL CONSULTANTS LTD | STOKE ON TRENT | A rating |
| FIRST MERX PARTS LIMITED | SOUTH OCKEND | A rating |
| First Mile LTD | London | A rating |
| First Milk Ltd | Glasgow | A rating |
| First Model Management London LTD | LONDON | A rating |
| First Network Limited | Northolt | A rating |
| First Option Care Services Ltd | Wellingborough | A rating |
| FIRST OPTION HEALTHCARE LIMITED | Croydon | A rating |
| First Place Consulting Limited | London | A rating |
| First Point 24 Ltd | Southend on Sea | A rating |
| First Point Physio Limited | Colchester | A rating |
| First Potteries Limited | Stoke on Trent | A rating |
| FIRST PRACTICE HEALTHCARE LTD | West Midlands | A rating |
| First Presbyterian Church ( Non-Subscribing ) Dromore | Dromore | A rating |
| First Prime Care Ltd | Diss | A rating |
| First Protocol Event Management Limited | London | A rating |
| First Psychology Ltd | Edinburgh | A rating |
| First Quality Care Limited | Leicester | A rating |
| First Quantum Minerals (UK) Limited | London | A rating |
| First Rail Holdings Limited | London | A rating |
| First Rate Recruit Limited | Northampton | A rating |
| FIRST RECRUITMENT LIMITED | Berkshire | A rating |
| First Rehab | Bolton | A rating |
| First Reliant Services Ltd | London | A rating |
| First Renderers Ltd | London | A rating |
| FIRST REPAIRS LTD | Canvey Island | A rating |
| First Response Finance Ltd | Nottingham | A rating |
| First Response Group Limited | Leeds | A rating |
| First Rung Ltd | London | A rating |
| First Sentier Investors (UK) Services Limited | London | A rating |
| First Sentinel Corporate Finance Limited | London | A rating |
| First South Yorkshire Limited | South Yorkshire | A rating |
| First Step Daycare & Nursery LTD | London | A rating |
| First Step Foods Limited T/a Heavenly Desserts | Brighton, | A rating |
| First Step Property Services Ltd | London | A rating |
| First Steps Care Ltd | London | A rating |