| Ultra Sports Clinic Limited | London | A rating |
| ULTRA SPORTS MEDICAL LTD | London | A rating |
| ULTRA STORES PREMIER LTD T/A PREMIER | ISLE OF WIGHT | A rating |
| Ultra Tough Limited | Hertfordshire | A rating |
| Ultracardiac Ltd | Plymouth | A rating |
| Ultracell (UK) Ltd | LIVERPOOL | A rating |
| Ultraleap Ltd | Bristol | A rating |
| Ultralight Superstrong Ltd | Manchester | A rating |
| Ultralytics Ltd | London | A rating |
| Ultrapolymers Ltd | Thelwall | A rating |
| UltraPrecision Motion Limited | Cricklade | A rating |
| Ultrasound Care Ltd | Liverpool | A rating |
| Ultrasound Direct Limited T/A Ultrasound Direct | Birmingham | A rating |
| ULTRASOUND LINK LTD | London | A rating |
| Ultrasound London Limited | Hatfield | A rating |
| Ultrasound Northwest Limited | Manchester | A rating |
| Ultrasound Scotland Ltd T/A Ultrasound Direct | Livingston | A rating |
| Ultrasound Sutton Ltd | Wallington | A rating |
| ULTRATECH PRODUCTS LTD | Lincolnshire | A rating |
| Ultratown Limited | London | A rating |
| Ultraviolet Cyber (UK) Limited | London | A rating |
| UltraVision International Ltd | Leighton Buzzard | A rating |
| Ultromics Limited | Oxford | A rating |
| ULTRON TECHNOLOGIES LTD | BIRMINGHAM | A rating |
| Uludag Group Limited | Edmonton | A rating |
| ULVA Insulation Systems Ltd | Shropshire | A rating |
| Ulverston Community Enterprises Limited | Ulverston | A rating |
| UM Education Ltd | London | A rating |
| UMA Advisory Ltd | Chalfont St. Peter | A rating |
| UMA LABS LIMITED | London | A rating |
| Uma Services Ltd | Bexleyheath | A rating |
| Uma Traders Limited t/a Fresh | Dagenham | A rating |
| UMA WEALTH (UK) LIMITED | London | A rating |
| Umada Limited t/a Heavenly Desserts Hull | Hull | A rating |
| Umadevi Pvt Limited | Edinburgh | A rating |
| UMAI FOOD LTD | Shrewsbury | A rating |
| Umair Naeem T/A Loco Food & Wine | London | A rating |
| Umar And Usman Limited | London | A rating |
| Umar Autos Limited | London | A rating |
| Umar Enterprises | Rochdale | A rating |
| Umar Ltd | London | A rating |
| UMAR QUALITY FOODS LTD | BOLTON | A rating |
| Umar Veg Ltd | London | A rating |
| UMAR'S PIZZAS LTD | Barnsley | A rating |
| UMAS International Limited | Shrewsbury | A rating |
| Umbrella Medical | Walsall | A rating |
| Umbrella Risk Management Limited | Aylesbury | A rating |
| Umbrl Limited | London | A rating |
| UMC SCOTLAND | EDINBURGH | A rating |
| ume Luxembourg SA | London | A rating |
| UMED FACILITIES MANAGEMENT LTD | Liverpool, England | A rating |
| Umeda Arts Theater International | London | A rating |
| UMEDA ARTS THEATRE UK LIMITED | London | A rating |
| Umeed Limited | LONDON | A rating |
| UMER BUILDERS & CONTRACTORS LTD | Ilford | A rating |
| Umer Travels Ltd | Newcastle upon Tyne | A rating |
| Umers Wallyford Ltd t/a Day Today | Wallyford | A rating |
| UMESHAN KANDASAMY T/a UK SERVICE STATION BP | HAVANT | A rating |
| UMF TECHNOLOGY CONSULTING LTD | Staines-Upon Thames | A rating |
| UMFOODS LTD | Wokingham | A rating |
| Umi | Tenby | A rating |
| UMi Commercial Limited | Durham | A rating |
| Umi Digital Solutions Ltd | London | A rating |
| Umi Oriental Food Limited Trading as Umi Japanese Bar & Restaurants | Middlesbrough | A rating |
| Umicore Marketing Services UK Ltd | Hertford | A rating |
| UMIT (NW) LTD | Liverpool | A rating |
| Umiya Limited T/a Eggfree Cake Box | London | A rating |
| Umka Limited | London | A rating |
| Umm ul Qura Foundation CIO | Bradford | A rating |
| Ummah Appeal | London | A rating |
| UMMAH APPEAL | WOOLWHICH | A rating |
| Ummah Care & Support Limited | Ilford | A rating |
| Ummanity LTD | London | A rating |
| UMN2P RETAILERS LTD | West Midlands | A rating |
| Umnai Limited | London | A rating |
| UMONY LIMITED | LONDON | A rating |
| uMotif Limited | London | A rating |
| UMRAH & HAJJ SPECIALIST LTD | Birmingham | A rating |
| Umrah Express Northampton Ltd | Northampton | A rating |
| Umrah Supermarket Hastings Ltd | Leicester | A rating |
| Umrah Supermarket Huddersfield Ltd | Huddersfield | A rating |
| Umrah Supermarket Northampton Limited T/A Umrah Supermarket | Northampton | A rating |
| UMS CONSTRUCTIONS LTD | CAMBRIDGESHIRE | A rating |
| UMSA COMMUNICATION LIMITED T/A World Phone | Chorley | A rating |
| Umud's Ventures Ltd | Barnsley | A rating |
| UMUM LTD | London | A rating |
| UMUT ADAR LTD | London | A rating |
| UMUTET LIMITED | London, | A rating |
| Umuzi Healthcare Agency Ltd | Thornton Heath | A rating |
| UMY Technic Ltd | Essex | A rating |
| UMY TRADING UK LTD | London | A rating |
| UN Global Trading Ltd | Hounslow | A rating |
| UNA PROPERTY CONSULTANCY LTD | HARROW | A rating |
| UNADKAT TRADING LTD T/A CROMWELL COMMUNITY STORE | HERTFORDSHIRE | A rating |
| Unanico Limited | London | A rating |
| UNATERRA CONSULTING LTD | Gateshead | A rating |
| Unatrac Limited | Slough | A rating |
| Unbiased Limited | London | A rating |
| Unboring Digital Ltd. | London | A rating |
| Unbound Advisors Limited | London | A rating |
| Unbound Creative Limited | London | A rating |
| Unbound Summits Ltd | London | A rating |
| Unbox Commerce Ltd | LONDON | A rating |
| Unboxed Consulting | London | A rating |
| Unboxed Consulting Limited | London | A rating |
| Unbridled Scotland Ltd | Aboyne | A rating |
| UNCAPPED LTD | London | A rating |
| Uncle Beef Ltd | Crayford, Dartford | A rating |
| Uncle Reg Ltd | London | A rating |
| UNCLE SAMS BROADWATER LTD T/A UNCLESAMS HAMBURGER EXPRESS | Worthing | A rating |
| UNCLES XENIAL LIMITED T/A BRAMLEY INN | TADLEY | A rating |
| Uncoded Limited | London | A rating |
| UNCOMMON BIO LIMITED | Cambridge | A rating |
| Uncommon Creative Studio Holding Limited | London | A rating |
| Uncommon Creative Studio Holding Ltd | London | A rating |
| Uncommonly Ltd | L:ondon | A rating |
| Unconventional Wisdom Ltd | Brentwood | A rating |
| Uncovered Group Ltd | London | A rating |
| Undaal LTD | West Midlands | A rating |
| UNDAR CONSULTANCY LIMITED | London | A rating |
| UNDER 1 TREE LIMITED | London | A rating |
| Under One Cloud Consultancy Ltd | Worthing | A rating |
| Under The Willow Limited | London | A rating |
| Underack Limited t/a Westbury Chemist | London | A rating |
| Underbelly Ltd | London | A rating |
| UNDERCLIFFE CRICKET CLUB | BRADFORD | A rating |
| Undercover Events Ltd | Sheerness | A rating |
| UNDERDOG BON LTD | London | A rating |
| Underdog Restaurants Ltd | London | A rating |
| Underfloor Heating Express Limited | London | A rating |
| Underground Ecom LTD | London | A rating |
| Underhill Residential Home | Plymouth | A rating |
| Understanding Care (Warwickshire) Limited | Stratford Upon Avon | A rating |
| UnderTheDoormat Ltd | London | A rating |
| Underwater Construction Corporation UK Ltd | Cumbria | A rating |
| Underwaterpistol Ltd | Moira | A rating |
| Underwood Hall Ltd T/As Wentworth Grange | Riding Mill | A rating |
| Underwood Meat Co Ltd | Rotherham | A rating |
| Underwood Solicitors LLP | London | A rating |
| UNDERWOOD STORES & Post Office | LONDON | A rating |
| Undisclosed Majority Ltd | London | A rating |
| UNDO Carbon Ltd | London | A rating |
| Undo Limited | Cambridge | A rating |
| UNDON LTD | Portsmouth | A rating |
| Une Forte Ltd | London | A rating |
| Une Normande a Londres | shepards bush | A rating |
| UNEEK CLOTHING COMPANY LIMITED | LONDON | A rating |
| UNEEK EVENTS UK LTD | Coventry | A rating |
| UNEEK FORWARDING LTD | ESSEX | A rating |
| Uneko Ltd | Livingston | A rating |
| Uneque Convenients Limited | Datchet | A rating |
| Unfabled Ltd. | London | A rating |
| Unhindr Ltd | London | A rating |
| UNI APPLICATION PORTAL LTD | London | A rating |
| UNI BARGAIN LIMITED | HALIFAX | A rating |
| Uni Compare Ltd | London | A rating |
| UNI HEALTH DISTRIBUTION LTD | DARTFORD | A rating |
| UNI LADDER CONSULTANCY LIMITED | London | A rating |
| UNI SPACE HOLDINGS LTD | England | A rating |
| UNI-FLY HeliworX Limited | Warwick | A rating |
| UNI4M MEDIA LIMITED | Manchester | A rating |
| Unibal Energy Limited | London | A rating |
| UNIBAR RESTAURANT LIMITED | HARROW | A rating |
| Unibis Limited | Manchester | A rating |
| Unibos Limited | Swindon | A rating |
| Unibuddy Limited | LONDON | A rating |
| UNIBUILD CONSTRUCTION LTD | LEICESTER | A rating |
| UNIC Care Services Ltd | CHESTERFIELD | A rating |
| Unica Construction Ltd | Doncaster | A rating |
| Unicard Ltd | Wimborne | A rating |
| Unicare London Ltd | Mill Hill | A rating |
| unicare pharmacy limited | littleborough | A rating |
| Unicaredevon Limited | Newton Abbot | A rating |
| Unicepta UK Limited | London | A rating |
| Unicity Medical Centre | Portsmouth | A rating |
| Unico UK Ltd | Milton Keynes | A rating |
| Unicore Trading Limited | Newcastle-Upon-Tyne | A rating |
| UNICORN ADVISOR (UK) LIMITED | London | A rating |
| Unicorn Asset Management | London | A rating |
| UNICORN AUTOMOTIVE LIMITED | WALTHAM ABBEY | A rating |
| Unicorn Brands Ltd | Luton | A rating |
| UNICORN CONSTRUCTION LTD | Harrow | A rating |
| Unicorn Inc Limited | Balerno | A rating |
| UNICORN PHARMACEUTICALS LIMITED | STANMORE | A rating |
| UNICORN PROJECTS | SOUTH CROYDON | A rating |
| UNICORN RESOLUTIONS LTD T/A FONE WORLD | Chatham | A rating |
| Unicorn Services Limited | London | A rating |
| UNICORN SHIPPING LIMITED | Heathrow | A rating |
| UniCourse Ltd | LIVERPOOL | A rating |
| Unicredit Bank GMBH London Branch | London | A rating |
| Unicut Precision Ltd | Herts | A rating |
| Unielectronics Ltd | Solihull | A rating |
| UNIEO CONSULTANTS LIMITED | London | A rating |
| UNIEXPERTS LIMITED | LUTON | A rating |
| Uniexpress Ltd | Bradford | A rating |
| Unifi Aviation UK Ltd | Kidlington | A rating |
| Unifi Communications Ltd | Twickenham | A rating |
| Unifi.id Ltd | London | A rating |
| UNIFIED CARE LTD | London | A rating |
| Unified Europe Ltd | Barking | A rating |