| UNIVERSAL SUPPORT SERVICES GROUP (USSG) LTD | Stockport | A rating |
| UNIVERSAL TAXIS LTD t/a Choice cars | Hemel Hempstead | A rating |
| Universal Trade Windows | Wolverhampton | A rating |
| Universal Trading Services Limited | Doncaster | A rating |
| Universal Transport Ltd | Telford | A rating |
| Universal Vibes Limited T/A Care Trainings | Harrow | A rating |
| Universally Speaking | Wyboston | A rating |
| Universe Solicitors Limited | LONDON | A rating |
| Universities and Colleges Christian Fellowship | Oxford | A rating |
| Universities and Colleges Information Systems Association Ltd | Oxford | A rating |
| Universities Superannuation Scheme Limited | Liverpool | A rating |
| University Campus of Football Business Limited | Wembley | A rating |
| University Centre Somerset College Group | Bridgwater | A rating |
| University College Birmingham | Birmingham | A rating |
| University College London | London | A rating |
| University College London Hospitals NHS Foundation Trust | London | A rating |
| University College School | London | A rating |
| University Dental Care Ltd | Swansea | A rating |
| University Dental Practice | Southampton | A rating |
| University for the Creative Arts | Surrey | A rating |
| University Health Service Southampton | Southampton | A rating |
| University Hospital Southampton NHS Foundation Trust | Southampton | A rating |
| University Hospitals Birmingham NHS Foundation Trust | Edgbaston | A rating |
| UNIVERSITY HOSPITALS COVENTRY AND WARWICKSHIRE NHS TRUST | COVENTRY | A rating |
| University Hospitals Dorset | Poole | A rating |
| University Hospitals North Midlands NHS Trust | Stoke-on-Trent | A rating |
| University Hospitals of Derby and Burton NHS Foundation Trust | Derby | A rating |
| University Hospitals of Leicester NHS Trust | Leicester | A rating |
| University Hospitals of Morecambe Bay NHS Foundation Trust | Barrow in Furness | A rating |
| University Hospitals Plymouth NHS Trust | Plymouth | A rating |
| University Hospitals Sussex NHS Foundation Trust | Chichester | A rating |
| University Jewish Chaplaincy | London | A rating |
| University of Aberdeen | Aberdeen | A rating |
| University of Bath | Bath | A rating |
| University of Bedfordshire | Luton | A rating |
| University of Birmingham | Birmingham | A rating |
| University of Bolton | Bolton | A rating |
| University of Bradford | Bradford | A rating |
| University of Brighton | Brighton | A rating |
| University of Brighton Academies Trust | Burgess Hill | A rating |
| University of Bristol | Bristol | A rating |
| University of Bristol Students' Union | Bristol | A rating |
| University of California Trust | London | A rating |
| University of Cambridge Investment Management Limited | Cambridge | A rating |
| University of Chester | Chester | A rating |
| University of Chicago Booth School of Business | London | A rating |
| University of Chichester | Chichester | A rating |
| University of Chichester (Multi) Academy Trust | Bognor Regis | A rating |
| University of Cumbria | Carlisle | A rating |
| University of Derby | Derby | A rating |
| University of Dundee | Dundee | A rating |
| University of Durham | Durham | A rating |
| University of East Anglia | Norwich | A rating |
| University of East London | London | A rating |
| University of Edinburgh | Edinburgh | A rating |
| University of Essex | Colchester | A rating |
| University of Exeter | Exeter | A rating |
| University of Glasgow | Glasgow | A rating |
| University of Gloucestershire | Cheltenham | A rating |
| University of Hertfordshire Higher Education Corporation | Hatfield | A rating |
| University of Hertfordshire Students' Union | Hatfield | A rating |
| University of Huddersfield | Huddersfield | A rating |
| University of Hull | Hull | A rating |
| University of Kent | Canterbury | A rating |
| University of Lancashire | Preston | A rating |
| University of Leeds (Human Resources) | Leeds | A rating |
| University of Leeds(Human Resources) | Leeds | A rating |
| University of Leicester | LEICESTER | A rating |
| University of Lincoln | Lincoln | A rating |
| University of Liverpool | Liverpool | A rating |
| University of London | London | A rating |
| University of Northampton Enterprises Limited | Northampton | A rating |
| University of Northampton Students' Union | Northampton | A rating |
| University of Notre Dame | London | A rating |
| University of Nottingham | Nottingham | A rating |
| University Of Nottingham Student Union | Nottingham | A rating |
| University of Oxford | Oxford | A rating |
| University of Plymouth | Plymouth | A rating |
| University of Portsmouth | Portsmouth | A rating |
| University of Reading | Reading | A rating |
| University of South Wales | Pontypridd | A rating |
| University of Southampton | Southampton | A rating |
| University of St Andrews | St Andrews | A rating |
| University of St Mark & St John | Plymouth | A rating |
| University of Staffordshire | Stoke on Trent | A rating |
| University of Stirling | Scotland | A rating |
| University of Stirling | Stirling | A rating |
| University of Strathclyde | Glasgow | A rating |
| University of Strathclyde Students' Association | Glasgow | A rating |
| University of Suffolk | Ipswich | A rating |
| University of Suffolk - Dental CIC | Ipswich | A rating |
| University of Sunderland | Sunderland | A rating |
| University of Surrey | Guildford | A rating |
| University of Sussex | Brighton | A rating |
| University of Sussex Students' Union | Falmer | A rating |
| University of Teesside | Middlesbrough | A rating |
| University of the Arts London | London | A rating |
| University of the Highlands and Islands | Inverness | A rating |
| University of the West of England | BRISTOL | A rating |
| University of the West of Scotland | Paisley | A rating |
| University of Ulster | Coleraine | A rating |
| University of Wales | Cardiff | A rating |
| University of Wales Trinity Saint David - Lampeter Campus | Lampeter | A rating |
| University of Wales Trinity St. David | Swansea | A rating |
| University of Warwick | Coventry | A rating |
| University of Westminster | London | A rating |
| University of Wolverhampton | Wolverhampton | A rating |
| University of York | York | A rating |
| University Schools Trust | London | A rating |
| Universum Wealth Ltd | London | A rating |
| Univerted Group Limited | London | A rating |
| UNIVERTED LIMITED | Elm Park | A rating |
| UNIVOYAGE LTD | LONDON | A rating |
| UNIWHEEL LIMITED | Haslemere | A rating |
| UNIWORLD FOODS LIMITED | DONCASTER | A rating |
| UNKNOWN COLLECTIONS 20 LTD | England | A rating |
| Unknown Works LTD | London | A rating |
| UNL Solutions Ltd | Loughborough | A rating |
| Unlatch UK Limited | London | A rating |
| Unleash Group Ltd | London | A rating |
| UNLEASHED DISCOVERY LTD | Sunderland | A rating |
| Unleashed.Company (London) Ltd | FOLKESTONE | A rating |
| Unlikely Artificial Intelligence Limited | Cambridge | A rating |
| UNLIMINT EU LTD | London | A rating |
| Unlimit Health | London | A rating |
| Unlimit UK Ltd | London | A rating |
| UNLIMITED TRENDS LTD | Twickenham | A rating |
| Unloc Learning Limited | Portsmouth | A rating |
| Unlocking Language Limited | London | A rating |
| Unloq Limited | Reading | A rating |
| Unlu Securities UK Limited | London | A rating |
| Unmade Limited | London | A rating |
| Unmind Limited | London | A rating |
| UNMP Limited | Worcestershire | A rating |
| UNO MOMENTO DARLINGTON LTD | Darlington | A rating |
| Unosquare Limited | Belfast | A rating |
| Unox UK Ltd | Camberley | A rating |
| UNQ SOLUTIONS LIMITED | Manchester | A rating |
| UNR Food Limited | Malvern | A rating |
| UNR LTD | Hereford | A rating |
| Unravel Technologies Limited | London | A rating |
| Unreliable Limited | London | A rating |
| Unruly Curls Ltd | London | A rating |
| UNRVLD LIMITED | LONDON | A rating |
| UNSA LIMITED | LEICESTER | A rating |
| Unseen (UK) | Bristol | A rating |
| UNSS LIMITED | Nelson | A rating |
| UNSTOPPABLES DIGITAL MEDIA LTD | London | A rating |
| Unsworth Cricket & Tennis Club Limited | Unsworth | A rating |
| Unsworth Group | Westhoughton | A rating |
| UNSY LIMITED | Brentwood | A rating |
| Untamd Ltd | London | A rating |
| Untamed Cat Food Limited | London | A rating |
| Untap Ltd | London | A rating |
| UnTappedshop Limited | London | A rating |
| Untha UK Ltd | Roecliffe | A rating |
| Untitled Advisors LLP | London | A rating |
| Untold Insights Ltd | London | A rating |
| UNTOLD STUDIOS LIMITED | LONDON | A rating |
| Unum Limited | Dorking | A rating |
| Unumplus Limited | London | A rating |
| Unusual Technologies Ltd | Brighton | A rating |
| UNV Accountants LTD | Watford | A rating |
| Unvar Hospitality Limited | Cardiff | A rating |
| UNW LLP | Newcastle upon Tyne | A rating |
| Unybrands Operations Ltd | Hemel Hempstead | A rating |
| Unyfi LTD | Bristol | A rating |
| Unyoked Ltd | London | A rating |
| UOL Development (UK) Limited | London | A rating |
| UOMA Beauty | London | A rating |
| UOMINI LTD | LONDON | A rating |
| Uomo Stius Limited | Luton | A rating |
| UP Enterprises Imports LTD | LEICESTER | A rating |
| UP Fitness Limited | Manchester | A rating |
| UP GRADE EDUCATIO N LTD | london | A rating |
| Up Health Limited | London | A rating |
| Up Hotel Agency Ltd | Rugby | A rating |
| Up Learn Limited | London | A rating |
| Up Market Estates Ltd T/A Edward Jones Estate Agents | Burton on Trent | A rating |
| UP Service Ltd T/a Parade Supermarket | Bradford | A rating |
| Up Your Elvis LLP | Lyme Regis | A rating |
| Up24 Seven Services Ltd | Derby | A rating |
| UP3 Services Ltd | London | A rating |
| Upakram Limited | Coventry | A rating |
| UPB AS Ltd | London | A rating |
| UPB Products Limited | London | A rating |
| UpClear, Ltd | London | A rating |
| UPCYCLED PLANT POWER (UPP) Ltd | Newport | A rating |
| Updates Media Limited T/A Nonsensical | Sutton Coldfield | A rating |
| Updraft WP Software Ltd | Newport | A rating |
| Upergy Limited | Solihull | A rating |
| UPG Developments Limited | London | A rating |
| UPGATE LTD | Leicester | A rating |
| UpGrad EdTech UK Limited | London | A rating |
| UPGRADE CONSTRUCTIONS LONDON LTD | Southall | A rating |
| UPGRO LIMITED | WOLVERHAMPTON | A rating |
| Uphall Tandoori Ltd | Broxburn | A rating |
| Upholland Pizzeria | Upholland | A rating |
| UPKEY LTD | Warrington | A rating |
| Upl Building Services Ltd | High Wycombe | A rating |