| Siem Capital UK Limited | Sutton | A rating |
| SIEMAG TECBERG UK Limited | Rugby | A rating |
| Siemens eMobility Charging Ltd | Hampshire | A rating |
| Siemens Energy Limited | Newcastle Upon Tyne | A rating |
| Siemens Gamesa Renewable Energy Limited | Hull | A rating |
| Siemens Healthcare Limited | Camberley | A rating |
| Siemens Holdings plc (including Siemens plc) | Camberley | A rating |
| Siemens Industry Software Limited | Farnborough | A rating |
| Siemens Mobility Limited | London | A rating |
| Siennico ventures | Stone | A rating |
| SIENT MAYA DRYLINING LTD | Nuneaton | A rating |
| SIERA CONSULTANCY LIMITED | ILFORD | A rating |
| Sierra Highlands Limited | Edinburgh | A rating |
| SIERRA LEONE HIGH COMMISSION | LONDON | A rating |
| Sierra Nevada Corporation Mission Systems UK Ltd | St Athan | A rating |
| Sierra Technologies Ltd | London | A rating |
| SIEVEMK Gateway Ltd | Milton Keynes | A rating |
| Sifcon International PLC | Waltham Cross | A rating |
| SiFive UK Ltd | Cambridge | A rating |
| Sift Limited | Bristol | A rating |
| Sifted (EU) Ltd | London | A rating |
| Sifty ML LTD | London | A rating |
| Sify Technologies Limited | London | A rating |
| SIG 1820 Ltd | Bicester | A rating |
| SIG Combibloc Ltd | Gateshead | A rating |
| SIG plc | Sheffield | A rating |
| SIG1820 Limited | Bicester | A rating |
| Siga UK Limited | Farnborough | A rating |
| Siga1966 UK Limited | Saffron Walden | A rating |
| SIGCARE LIMITED | Watford | A rating |
| sight cymru cio | Pontypool | A rating |
| Sight For Life | Manchester | A rating |
| Sight System Limited | Brough | A rating |
| Sightcall Limited | London | A rating |
| SIGHTHILL SUPERMARKET LTD | Edinburgh | A rating |
| SIGIRIYA RESTAURANTS LTD | HALE | A rating |
| Sigla Ltd | Manchester | A rating |
| Sigma 786 Limited T/A Fone Booth | Barnsley | A rating |
| Sigma Autos Ltd | Edgware | A rating |
| Sigma Broking Limited | London | A rating |
| SIGMA BUSINESS ACCOUNTANTS LTD | Bury St. Edmunds | A rating |
| SIGMA BUSINESS INTELLIGENCE SERVICES (PVT) LTD | Kingston Upon Thames | A rating |
| Sigma Computing UK Limited | London | A rating |
| SIGMA CONNECTED GROUP LTD | Reddich | A rating |
| Sigma Corporation Ltd | Hounslow | A rating |
| Sigma dental limmited | Nottingham | A rating |
| SIGMA DESIGN & BUILD LTD | Uxbridge, | A rating |
| Sigma Engineering Product Design Ltd | Irvine | A rating |
| SIGMA INDUSTRIAL SYSTEMS LTD | LONDON | A rating |
| SIGMA LABS XYZ LTD | London | A rating |
| Sigma Lithium Limited | Abingdon | A rating |
| SIGMA OCCUPATIONAL HEALTH LTD | WOLVERHAMPTON | A rating |
| Sigma Pharmaceuticals Plc | Watford | A rating |
| SIGMA RECTRIX SYSTEMS (UK) LIMITED | saflord | A rating |
| SIGMA SOFTWARE HOLDING LTD | London | A rating |
| Sigma-HSE (UK) Ltd | Winchester | A rating |
| SIGMA.AI DATA LTD | London | A rating |
| Sigma+Star Limited | Pembroke Dock | A rating |
| SIGMA4UK LTD | LONDON | A rating |
| SIGMAFIELD LIMITED | London | A rating |
| Sigmaplace Ltd | Wallsend | A rating |
| SigmaRoc Plc | London | A rating |
| Sigmatax Limited | Huddersfield | A rating |
| SigmaTEK Europe | Tamworth | A rating |
| Sigmatex (UK) Ltd | Runcorn | A rating |
| SIGMUS LIMITED | London | A rating |
| SIGN GENIUS LIMITED | London | A rating |
| Sign In App Ltd | Northampton | A rating |
| Sign Language Interactions | Glasgow | A rating |
| Sign of the Times | London | A rating |
| Sign Pro International Limited | Ilford | A rating |
| Sign Reload Ltd | Dungannon | A rating |
| Sign Salad Ltd | London | A rating |
| Sign Shop Ltd | Birmingham | A rating |
| Sign Stop Ltd | London | A rating |
| Signa Care Group Ltd | Sunderland | A rating |
| Signable Limited | Bristol | A rating |
| Signal Capital Partners Limited | London | A rating |
| Signal Media Limited | London | A rating |
| Signal Ocean Limited | London | A rating |
| SIGNANT HEALTH LIMITED | Reading | A rating |
| Signatory Vintage Scotch Whisky Co Ltd | Pitlochry | A rating |
| Signatur Biosciences | Thame | A rating |
| SIGNATURE 187 LIMITED | Dagenham | A rating |
| SIGNATURE BEDS LIMITED | Batley | A rating |
| Signature Brew Ltd | London | A rating |
| Signature Cookware Limited | Enfield | A rating |
| Signature Flatbreads UK Ltd | Dunstable | A rating |
| Signature Flight Support London Luton Limited | Luton | A rating |
| SIGNATURE GLOBAL SERVICE LIMITED | LONDON | A rating |
| Signature Healthcare Ltd | Birmingham | A rating |
| Signature Healthcare Services Limited | London | A rating |
| Signature Hotel Group Ltd | Rugby | A rating |
| SIGNATURE HOTEL LONDON LTD | Ilford | A rating |
| Signature Jobs Ltd | Hayes | A rating |
| SIGNATURE LEISURE LIMITED | Batley | A rating |
| Signature Litigation LLP | London | A rating |
| Signature Medical Limited | Glasgow | A rating |
| SIGNATURE OF THAI LTD | Edinburgh | A rating |
| Signature Pubs Limited | Aberdeen | A rating |
| Signature Realtors Ltd | CARDIFF | A rating |
| Signature Senior Lifestyle Ltd | Beaconsfield | A rating |
| Signature Smile TC Ltd | Chelmsford | A rating |
| Signature Sweets Ltd T/A Signature Sweets | Leeds | A rating |
| SIGNATURE THAI CLINIC LTD | Edinburgh | A rating |
| Signature UK Business Solutions Limited | London | A rating |
| Signature X Limited | London | A rating |
| Signatures Italian Restaurant | Sunderland | A rating |
| Signet Capital Management Limited t/a Signet | London | A rating |
| SIGNET CORPORATION LTD | Grays | A rating |
| SIGNET HEALTHCARE LIMITED | Eastcote | A rating |
| Signet Hotels (United Kingdom) Ltd | East Molesey | A rating |
| Signet Labs Limited | London | A rating |
| Signet Polo Team | Reading | A rating |
| Signet Polo Team Limited | Bagshot | A rating |
| Signet Trading Ltd | Watford | A rating |
| SIGNIFLY LTD | London | A rating |
| Signify Commercial UK Limited | Surrey | A rating |
| Signify Group Limited | London | A rating |
| Signify Research Limited | Bedford | A rating |
| SIGNIFYC Limited T/a Open Consulting | Pinner | A rating |
| Signifyd UK Ltd | London | A rating |
| Signode UK Ltd | Aldridge | A rating |
| Signol Limited | London | A rating |
| signorelli's deli ltd | cambridge | A rating |
| SIGNORINA HOMES LTD | Sunderland | A rating |
| Signs Base Limited | Witham | A rating |
| SIGNS TECH LTD | Wolverhampton | A rating |
| Signum Global Advisors (UK) Limited | Hove | A rating |
| SIGNUM INTELLIGENCE LTD | Chester | A rating |
| Sigtech Solutions Limited | Maidenhead | A rating |
| SIGULER GUFF UK LLP | London | A rating |
| Siguru AI | London | A rating |
| SIGWATCH Ltd | London | A rating |
| siHealth Ltd | Didcot | A rating |
| SIHRA REFRIGERATION | MAIDENHEAD | A rating |
| SII Services Limited | London | A rating |
| SII TECHNOLOGIES LTD | Birmingham | A rating |
| Sika Limited | Welwyn Garden City | A rating |
| SIKANDER CONSTRUCTION LTD | Bexleyheath | A rating |
| Sikara Media Ltd T/A CAD League | Edenbridge | A rating |
| Sikdar Consulting Ltd | Tadley | A rating |
| Sikdar Medical Ltd Trading as Brightlife Chemist | Tadley | A rating |
| SIKDER ENTERPRISE LTD | Dartford | A rating |
| Sikh Academies Trust | Slough | A rating |
| Sikh Association Manchester | Manchester | A rating |
| Sikh Channel | Birmingham | A rating |
| Sikh Gurdwara Cardiff | Cardiff | A rating |
| sikh temples kabaddi club birmingham ltd | west bromwich | A rating |
| SIKKA PHARMA LTD T/A WINNERSH PHARMACY AND CLINIC | WINNERSH | A rating |
| SIKLA UK LTD | MILTON KEYNES | A rating |
| SIKMA SPORTS LIMITED | CROYDON | A rating |
| Sikor London Limited | London | A rating |
| Sikraft Infotech ( Nuclear Energy ) Limited | Harrow | A rating |
| SIKY LIMITED | Huddersfield | A rating |
| SIL Holdings Ltd | Bradford | A rating |
| Silbury Marketing Limited | Banbury | A rating |
| Silchester Control systems | Four Marks | A rating |
| Silcs Solutions Limited | London | A rating |
| Sildon Limited | Basildon | A rating |
| Sileby Fish Bar Limited | Loughborough | A rating |
| Sileby Town Cricket Club | LOUGHBOROUGH | A rating |
| Silent Bob Ltd T/A D H Roberts Chemist | London | A rating |
| Silent Creek Limited | London | A rating |
| Silent E Pictures Limited | London | A rating |
| Silent Games Ltd | Newcastle Upon Tyne | A rating |
| SILENT NIGHT MANAGEMENT LTD t/a The Gresham Hotel | London | A rating |
| SILENT VALLEY FERTILIZERS LTD | NEWRY | A rating |
| Silestia Ltd | Orpington | A rating |
| Silex Partners Limited | London | A rating |
| Silhani Beauty Limited | London | A rating |
| Silhouette Research & Technology Limited | Plymouth | A rating |
| Silhouette UK Ltd | London | A rating |
| Silian Partners UK Ltd | London | A rating |
| Silica Infotech Limited | Leicester | A rating |
| Silicon Biztech Limited | Croydon | A rating |
| Silicon Frontline Technology (UK) Limited | Reading | A rating |
| Silicon Gene Ltd | Bromley | A rating |
| Silicon Grid Ltd | Manchester | A rating |
| SILICON LABORATORIES UK LIMITED | Camberley | A rating |
| SILICON LOGIC UK LIMITED | London | A rating |
| Silicon Microgravity Limited | Cambridge | A rating |
| Silicon Shops Limited | Alloa | A rating |
| SILICON TECHNIX LIMITED | London | A rating |
| Silimed UK Limited | West Drayton | A rating |
| Silixa Ltd | Elstree | A rating |
| SILIXON Limited | London | A rating |
| Silk & Cotton LTD | Bromley | A rating |
| Silk Agency Ltd | London | A rating |
| Silk Factory Ltd | London | A rating |
| Silk House Hotel Ltd | Barking | A rating |
| SILK ROAD OASIS LIMITED | Maidenhead | A rating |
| SILK TOUCH FABRICS | Birmingham | A rating |
| SILK Ventures | London | A rating |
| SILKSS DRY CLEANERS LTD | London | A rating |
| SILKWAYZ LTD | London | A rating |
| SILKY CONSULTANCY LTD | Farnham | A rating |
| Silloth Group Medical Practice | Wigton | A rating |
| Sillywater Ltd T/A Caremark (Arun) | Arundel | A rating |
| SILO LIMITED | HARROW | A rating |