| WEIR GROUP PLC | GLASGOW | A rating |
| Weisscomm Partners Ltd t/a Real Chemistry | London | A rating |
| WEKAIO UK Limited | Bicester | A rating |
| Welbond Armatures UK Ltd | London | A rating |
| WELL'COM RAIL UK LTD | London | A rating |
| Wella UK Limited | London | A rating |
| Wellcom London Limited | London | A rating |
| Wellington Management International Limited | London | A rating |
| Wells Fargo Bank N.A. | London | A rating |
| Wells Fargo Securities International Limited | London | A rating |
| Welltec (UK) Ltd | Dyce | A rating |
| Welwing Capital UK Limited | London | A rating |
| Wempe Limited UK | London | A rating |
| WENDY'S RESTAURANTS OF U.K. LIMITED | Smallfield | A rating |
| Wentworth Resources (UK) Limited | Richmond-upon-Thames | A rating |
| WEPA UK Ltd | Bridgend | A rating |
| WEPOINT UK LIMITED | London | A rating |
| WeSoar Limited | London | A rating |
| Wessex Water Services Ltd | Bath | A rating |
| Westbridge FoodsLtd | Malvern | A rating |
| Westbrook Europe (UK) LLP | London | A rating |
| Westcon Group European Operations Ltd | Cirencester | A rating |
| WESTEC Holding Company Ltd | Burgess Hill | A rating |
| Western Asset Management Company Limited | London | A rating |
| Western Digital (UK) Limited | Guilford | A rating |
| Western Union Payment Services Ireland Limited | London | A rating |
| Westernacher & Partner Consulting Limited | Esher | A rating |
| WesternGeco Limited | Crawley | A rating |
| Westfalia Fruit International Limited | West Malling | A rating |
| Westfield Europe Limited | London | A rating |
| Westfield Specialty Managing Agency Limited | London | A rating |
| WESTINGHOUSE ELECTRIC UK HOLDINGS LIMITED | Preston | A rating |
| Westmill Foods Limited | Enfield | A rating |
| Weston Importers Ltd | Huntingdon | A rating |
| Westpac Banking Corporation | London | A rating |
| Westwood Global Energy Limited | Aberdeen | A rating |
| WeWork International Limited | London | A rating |
| WEX Europe Limited | London | A rating |
| WFW Global LLP | London | A rating |
| WH TRADING UKCT LTD | London | A rating |
| Whaleco UK Limited | London | A rating |
| Whatfix Limited | London | A rating |
| Whatnot Global Limited | London | A rating |
| Wheelabrator Group Limited | Altrincham | A rating |
| Wheely Technologies Ltd | London | A rating |
| Whereby UK Operations Ltd | London | A rating |
| Whessoe Engineering Limited | Darlington | A rating |
| Whim Hospitality Limited | Swindon | A rating |
| Whitbread Group Plc | Dunstable | A rating |
| White & Case LLP | London | A rating |
| White Arkitekter | London | A rating |
| White Cube Limited | London | A rating |
| White Star Capital United Kingdom Limited | London | A rating |
| Whitecliff Management Corporation Limited | London | A rating |
| WHITECROFT LIGHTING LIMITED | ASHTON-UNDER-LYNE | A rating |
| Whitefox Technologies Limited | London | A rating |
| WHIZZ EDUCATION LIMITED | London | A rating |
| Wideplank (London) Ltd | London | A rating |
| Wieden & Kennedy UK Ltd | London | A rating |
| Wieland Metals Birmingham | Birmingham | A rating |
| Wika Instruments Limited | Sevenoaks | A rating |
| Wikborg Rein LLP | London | A rating |
| Wilben Trade (UK)Limited | London | A rating |
| Wild Brain Family International Limited | London | A rating |
| Wilfred T Fry Ltd | Worthing | A rating |
| Wilhelmina London Limited | London | A rating |
| Wilhelmsen Ships Service Limited | Dartford | A rating |
| Wilkinson Sword Limited | London | A rating |
| William Blair International Limited | London | A rating |
| William Grant & Sons Ltd | Dufftown | A rating |
| William Hare Limited | Bury | A rating |
| William Hill | Leeds | A rating |
| William Morris Endeavor Entertainment (U.K.) Ltd | LONDON | A rating |
| Williams College Oxford Programme | Oxford | A rating |
| Williams Lea | London | A rating |
| Willis Limited | London | A rating |
| Willis Re (UK) Limited | London | A rating |
| Willkie Farr & Gallagher (UK) LLP | London | A rating |
| Wilmer Cutler Pickering Hale and Dorr LLP (trading as WilmerHale) | London | A rating |
| Wilmington Trust SP Services (London) Limited | London | A rating |
| Wilson Elser Limited | London | A rating |
| Wilson Sonsini Goodrich & Rosati (UK) LLP | London | A rating |
| Wilson Tool International (Europe) Ltd | Swindon | A rating |
| Wilton Group Limited | London | A rating |
| WIM Technologies | London | A rating |
| Wimberly Allison Tong & Goo (UK) Ltd | London | A rating |
| Winbro Group Technologies | Shepshed | A rating |
| Wincent Services (UK) Limited | London | A rating |
| Winchester Procurement Limited | Winchester | A rating |
| Wincraft Music Ltd | Cheltenham | A rating |
| WINDWARD MARINE RISK (UK) LTD | London | A rating |
| WINE-SEARCHER UK LIMITED | London | A rating |
| Winfo Solutions UK Limited | London | A rating |
| WING AVIATION UK LIMITED | LONDON | A rating |
| WINIT (UK) LIMITED | Tamworth | A rating |
| WINLIFE LTD | Ilford | A rating |
| WINNINGTEMP LIMITED | LONDON | A rating |
| WINSPIRE SOLUTIONS UK LIMITED | London | A rating |
| Winston & Strawn London | London | A rating |
| Winston Taylor International LLP | London | A rating |
| Winston Taylor UK LLP | London | A rating |
| WINT-WI UK LIMITED | LONDON | A rating |
| Winteg Limited | London | A rating |
| Winton Capital Management Ltd | London | A rating |
| WIOSS WITRON On Site Services GmbH | Keele | A rating |
| Wipac Technology Limited | Buckingham | A rating |
| Wipro Appirio UK Limited | London | A rating |
| WIPRO CONNECTED SERVICES UK LIMITED | Reading | A rating |
| Wipro Limited | London | A rating |
| WISDOMTREE IRELAND LIMITED | Soho, London | A rating |
| Wise Music Group Limited | London | A rating |
| WiseTech Global UK Limited | London | A rating |
| Wismettac Harro Foods Ltd | Chessington | A rating |
| WISON OFFSHORE & MARINE (HONG KONG) LIMITED - UK Establishment | London | A rating |
| WISS, JANNEY, ELSTNER LIMITED | London | A rating |
| Wissen Technology Limited | Harrow | A rating |
| Withers LLP | London | A rating |
| WITHIN LONDON LTD | London | A rating |
| Witt/Kieffer International Limited | London | A rating |
| WITTENSTEIN high integrity systems Ltd | Bristol | A rating |
| WIX.COM (UK) LIMITED | London | A rating |
| Wizz Air UK Limited | Luton | A rating |
| WJ Groundwater Limited | Kings Langley | A rating |
| WJR Developments UK Limited | London | A rating |
| WM Shipping Ltd (trading as Santova Logistics) | Tamworth | A rating |
| WMGS Europe Limited | London | A rating |
| WNC UK Limited | Slough | A rating |
| WNS Global Services (UK) | LONDON | A rating |
| WobbleWorks (UK) Limited | Milton Park | A rating |
| Wockhardt UK Limited | Wrexham | A rating |
| Wolfe Research (UK) Limited | London | A rating |
| Wolfram Research Europe Ltd | Long Hanborough | A rating |
| Wolfspeed Europe GmbH | Milton Keynes | A rating |
| Wolters Kluwer (UK) Ltd | Surrey | A rating |
| Wolverhampton Wanderers FC (1986) Ltd. | Wolverhampton | A rating |
| Wolverine Europe Limited | London | A rating |
| Women's Best UK Ltd | London | A rating |
| Wonderfield Group Limited | London | A rating |
| Wood Group UK Limited | Aberdeen | A rating |
| Woodhall Capital International | London | A rating |
| Woods Bagot Europe Ltd | London | A rating |
| Woodsford Tradebridge Limited | London | A rating |
| WOODSIDE ENERGY (UK) LIMITED | London | A rating |
| Woodside Energy Trading Singapore PTE Ltd (UK Branch) | London | A rating |
| Woolmark International Pty Ltd | Surrey | A rating |
| Woori Bank | London | A rating |
| Wordbank Marketing Limited | London | A rating |
| Workable Software Limited | London | A rating |
| Workato UK Ltd | London | A rating |
| Workday (UK) Limited | London | A rating |
| Workforce HCM Limited | London | A rating |
| Workfox UK Ltd | Ipswich | A rating |
| Workiva UK Ltd | London | A rating |
| Workshare Limited | Kingston Upon Thames | A rating |
| World Association of Nuclear Operators | London | A rating |
| World Brands Duty Free Ltd | London | A rating |
| World Federation of Advertisers-UK | London | A rating |
| World First UK Limited | London | A rating |
| World Fuel Services Europe Limited | London | A rating |
| World Nuclear Transport Ltd | London | A rating |
| World Vision International Global Centre | Uxbridge | A rating |
| World Vision UK | Milton Keynes | A rating |
| World Wrestling Entertainment (International) Limited | London | A rating |
| WorldCC UK Ltd | Petersfield | A rating |
| Worldline IT Services UK Limited | Beeston | A rating |
| WORLDONE RESEARCH LTD | London | A rating |
| WorldPay (UK) Ltd | London | A rating |
| WorldRemit Ltd | London | A rating |
| WORLDWIDE BUSINESS RESEARCH LIMITED | LONDON | A rating |
| WorldWide Clinical Trials | Nottingham | A rating |
| Worldwide Flight Services Limited | London | A rating |
| Worldwide Production Agency | London | A rating |
| Worley Europe Limited | London | A rating |
| Woven by Toyota UK Limited | London | A rating |
| Wozair Limited | Gillingham | A rating |
| WPP 2005 Limited | London | A rating |
| WPP Brands (UK) Limited | London | A rating |
| WPP Media UK Limited | London | A rating |
| WPP Production Limited | London | A rating |
| Wrafton Laboratories Limited (Perrigo UK) | Braunton | A rating |
| Wren House Infrastructure Management Limited | London | A rating |
| Wren Kitchens Limited | Barton-Upon-Humber | A rating |
| WSELP Manco Ltd | London | A rating |
| WSO2 (UK) Limited | London | A rating |
| WSP Group Limited | London | A rating |
| WTA Tour Inc | London | A rating |
| Wunderkind Technologies UK Ltd | London | A rating |
| Wunderman Thompson Commerce UK Limited | London | A rating |
| Wurth UK Ltd | Erith | A rating |
| WuXi AppTec UK Ltd | Cambridgeshire | A rating |
| WuXi Biologics UK Ltd | London | A rating |
| WW GBR Ltd | Slough | A rating |
| WW Norton & Company LTD | London | A rating |
| WWF-WORLD WIDE FUND FOR NATURE (FORMERLY WORLD WILDLIFE FUND) | Woking | A rating |
| WWT EMEA UK Limited | London | A rating |
| Wynden Stark Limited | London | A rating |
| Wyndham Hotel Group Europe Limited | London | A rating |
| X INTERNET UK LIMITED | LONDON | A rating |
| X-Edit Limited (trading as EditShare) | Basingstoke | A rating |
| X-Press Container Line (UK) Limited | Southampton | A rating |