| SHL Group Limited | Surrey | A rating |
| SHOALTER AUTOMATION (UK) LIMITED | Metroplex | A rating |
| Shoda Sauces Europe Co Limited | Abertillery | A rating |
| Shoosmiths LLP | London | A rating |
| SHOP TJC LTD | Feltham | A rating |
| Shopify UK Limited | London | A rating |
| Shopware UK Limited | Manchester | A rating |
| Shotton Mill Limited | Deeside | A rating |
| Showpad Ltd | Brough | A rating |
| SHOWROOMPRIVE UK LTD | LONDON | A rating |
| SHUN XIN CENTURY LTD | London | A rating |
| Shure UK Limited | Waltham Abbey | A rating |
| Shurgard UK Limited | Weybridge | A rating |
| Shutterstock (UK) Ltd | London | A rating |
| SIAE MICROELETTRONICA Limited | Liverpool | A rating |
| Sice Previt UK Ltd | London | A rating |
| SICK (UK) Ltd | St Albans | A rating |
| Siderise Insulation Ltd | Maesteg | A rating |
| Siderpark LTD | Chippenham | A rating |
| Sidetrade UK Limited | London | A rating |
| Sidley Austin LLP | London | 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 |
| Sierra Nevada Corporation Mission Systems UK Ltd | St Athan | A rating |
| Sierra Technologies Ltd | London | A rating |
| SiFive UK Ltd | Cambridge | A rating |
| Sify Technologies Limited | London | A rating |
| SIG Combibloc Ltd | Gateshead | A rating |
| Sightcall Limited | London | A rating |
| Sigla Ltd | Manchester | A rating |
| SIGMA CONNECTED GROUP LTD | Reddich | A rating |
| Signal Media Limited | London | A rating |
| SIGNANT HEALTH LIMITED | Reading | A rating |
| Signature Flatbreads UK Ltd | Dunstable | A rating |
| Signature Flight Support London Luton Limited | Luton | A rating |
| Signature UK Business Solutions Limited | London | A rating |
| Signet Capital Management Limited t/a Signet | London | A rating |
| Signify Commercial UK Limited | Surrey | A rating |
| Signifyd UK Ltd | London | A rating |
| Signum Global Advisors (UK) Limited | Hove | A rating |
| Sigtech Solutions Limited | Maidenhead | A rating |
| SIGULER GUFF UK LLP | London | A rating |
| Sika Limited | Welwyn Garden City | A rating |
| Sikraft Infotech ( Nuclear Energy ) Limited | Harrow | A rating |
| Silbury Marketing Limited | Banbury | A rating |
| Silhouette Research & Technology Limited | Plymouth | A rating |
| Silian Partners UK Ltd | London | A rating |
| Silicon Gene Ltd | Bromley | A rating |
| SILPHIUM ASSET MANAGEMENT LIMITED | LONDON | A rating |
| SILVACO EUROPE LTD | ST IVES | A rating |
| Silver Lake Europe LLP | London | A rating |
| Silver Point Capital Europe, Ltd | London | A rating |
| Silver Touch Technologies (UK) Limited | Chelmsford | A rating |
| SILVERBACK SMART TECHNOLOGY LIMITED | London | A rating |
| Silverbrook Holdings Limited | London | A rating |
| Silverlink Technologies Ltd | London | A rating |
| Silversea Cruises UK Limited | London | A rating |
| Silverstream Technologies (UK) Limited | London | A rating |
| SimCorp Limited | London | A rating |
| Simmons & Simmons LLP | London | A rating |
| Simon Carves Engineering Ltd | Manchester | A rating |
| Simon-Kucher & Partners Strategy & Marketing Consultants | London | A rating |
| Simple Machines EMEA Limited | London | A rating |
| Simple.Life Apps UK Ltd | Walthamstow | A rating |
| simplehuman UK Ltd | London | A rating |
| Simpleshow UK Ltd | Greater London | A rating |
| Simply Bearings Ltd | Leigh | A rating |
| Simply TV UK Limited | Altrincam | A rating |
| SIMPPLR Limited | Reading | A rating |
| Simpragma Solutions Ltd | Bromley | A rating |
| Simpson Spence Young | London | A rating |
| Simpson Strong-Tie International, Inc. | Tamworth | A rating |
| SIMPSON THACHER & BARTLETT LLP | LONDON | A rating |
| Sinch UK Ltd | Canterbury | A rating |
| Sinclair Pharmaceuticals Limited | Chester | A rating |
| SINEVIS TECHNOLOGIES UK LTD | Ruislip | A rating |
| Sing Tao (UK) Ltd | Cricklewood | A rating |
| Singapore Airlines Ltd | Chiswick | A rating |
| Singapore Economic Development Board | London | A rating |
| Singapore Exchange Limited | London | A rating |
| Singapore Tourism Board | London | A rating |
| Single Buoy Moorings (UK) Limited | Belfast | A rating |
| Singlestore UK Limited | London | A rating |
| Singtel (Europe) Limited | London | A rating |
| Singular Systems UK Limited t/a Singular Systems | London | A rating |
| Sinochem (United Kingdom) Ltd | London | A rating |
| Sinochem International Oil (London) Co Limited | London | A rating |
| Sinolingua London Limited | London | A rating |
| Sinomine Specialty Fluids Ltd | Aberdeen | A rating |
| Sinopec Century Bright Capital Investment (UK) Limited | London | A rating |
| Sinosure | London | A rating |
| SINTEC UK LIMITED | LONDON | A rating |
| Sintecmedia WEM Ltd | Herts | A rating |
| SIPRAL UK LIMITED | London | A rating |
| Sipral UK Ltd | London | A rating |
| Siri Lifestyle Limited | London | A rating |
| SirionLabs Limited | London | A rating |
| SIRIUS FIBER LTD | London | A rating |
| SiriusPoint International Insurance Corporation | London | A rating |
| SIS (UK) Limited | Maryport | A rating |
| SISL INFOTECH UK LTD | UXBRIDGE | A rating |
| SITA Advanced Travel Solutions Ltd | Reading | A rating |
| SITA Information Networking Computing UK Ltd | Hayes | A rating |
| Sitecore UK Ltd. | London | A rating |
| Sitemate Services UK Limited | London | A rating |
| SiteMinder Distribution Limited | Birmingham | A rating |
| Sitetracker UK Limited | London | A rating |
| SIX DEGREES HOLDINGS LIMITED | LONDON | A rating |
| SIX Financial Information UK Ltd | London | A rating |
| SIXT Rent a Car Ltd | Slough | A rating |
| Sixth Street Europe LLP | London | A rating |
| SJH Scientific Limited | Halse | A rating |
| SK ECOPLANT CO., LTD | LONDON | A rating |
| SK Energy Europe Ltd | London | A rating |
| Sk Hynix Nand Product Solutions UK Limited (t/a Solidigm) | Swindon | A rating |
| SK HYNIX UK LIMITED | Weybridge | A rating |
| Skadden,Arps,Slate,Meagher & Flom (UK) LLP | London | A rating |
| Skanska UK Plc | Watford | A rating |
| Skedulo UK LTD | Burnham | A rating |
| SKF (U.K.) Limited | Luton | A rating |
| Skidmore Owings & Merrill (Europe) LLP | London | A rating |
| Skillnet Solutions Private Limited | Richmond | A rating |
| SKIM London Ltd. | London | A rating |
| Skimbit Ltd | London | A rating |
| SkindocUK Ltd | London | A rating |
| Sky UK Limited | Middlesex | A rating |
| Sky UK New Co Limited | London | A rating |
| Skybound Capital UK Ltd | London | A rating |
| Skyrora Limited | Cumbernauld | A rating |
| Skyscanner Limited | Edinburgh | A rating |
| SkyShowtime Limited | Isleworth | A rating |
| Slalom Consulting Limited | London | A rating |
| Slate Asset Management (Europe) Limited | London | A rating |
| Slater & Gordon (UK) 1 Limited | Manchester | A rating |
| Slaughter and May | London | A rating |
| SLC Turnberry Ltd - Trump Turnberry | Turnberry | A rating |
| SLFC Services Company (UK) limited | Basingstoke | A rating |
| SlideGenius Limited | London | A rating |
| SLK UK Private Limited | LONDON | A rating |
| SLR Consulting Limited | London | A rating |
| Smarsh Software UK Ltd | London | A rating |
| SMART TRADE TECHNOLOGIES UK LIMITED | London | A rating |
| Smartech Retail Group Limited | London | A rating |
| SMARTER GRID SOLUTIONS LTD | Glasgow | A rating |
| Smartly.io Solutions Ltd | Slough | A rating |
| SMARTRENTAL REINO UNIDO LTD | London | A rating |
| SMARTSHEET UK LIMITED | London | A rating |
| SmartStream Technologies Ltd | Bristol | A rating |
| Smartsway Limited | Eastbourne | A rating |
| SMBC Bank International plc | London | A rating |
| SMBC Nikko Capital Markets Limited | London | A rating |
| SMC Corporation (UK) Ltd | Milton Keynes | A rating |
| SMG Europe | Manchester | A rating |
| Smiggle UK Ltd | London | A rating |
| Smile Identity UK, Limited | London | A rating |
| Smiley Monroe Limited | Lisburn | A rating |
| Smith & Nephew Plc | Watford | A rating |
| Smith Global Services UK Ltd | Maidenhead | A rating |
| Smith Stone Walters Limited | London | A rating |
| Smith,Gambrell & Russell International LLP | London | A rating |
| Smithers ERS Limited | Harrogate | A rating |
| Smiths Detection Group Limited | London | A rating |
| Smithy Mushrooms Ltd | Ormskirk | A rating |
| SMK Electronics Europe UK Branch | Newton Aycliffe | A rating |
| SML EUROPE LTD | CORBY | A rating |
| SMOKEBALL UK LTD | London | A rating |
| SMOORE UK CO., LTD | London | A rating |
| SMR Automotive Mirrors UK Ltd | Portchester | A rating |
| SMS Group Technical Services UK Limited | Chesterfield | A rating |
| Smulders Projects UK Ltd | Wallsend | A rating |
| Smurfit Kappa UK Limited | Liverpool | A rating |
| Snap Finance Ltd | Milton Keynes | A rating |
| Snap Group Limited | London | A rating |
| SNAP-ON UK HOLDINGS LIMITED | KETTERING | A rating |
| SnapLogic UK Limited | London | A rating |
| Snappy App UK Limited | London | A rating |
| SNG GROUP LIMITED | Bridgnorth | A rating |
| Snovasys Software Solutions Limited | Middlesex | A rating |
| Snow Peak London Limited | Godalming | A rating |
| Snowflake Computing U.K. Limited | London | A rating |
| Soap and Co UK Ltd t/a SAKARE | London | A rating |
| Social Plus Europe Ltd | Uxbridge | A rating |
| Sociedad Iberica de Construcciones Electricas S.A. | Reading | A rating |
| Sociedade Nacional de Combustiveis de Angola | Knightsbridge | A rating |
| Societe Generale Equipment Finance Ltd | London | A rating |
| Societe Generale International Limited | London | A rating |
| Societe Generale London Branch | London | A rating |
| Society of Petroleum Engineers Europe Limited | London | A rating |
| Socomec U.K Limited | Cirencester | A rating |
| Socotec UK Limited | Burton Upon Trent | A rating |
| Soderberg & Partners Technology And Services Ltd | Bristol | A rating |
| Sodexo UK Limited | Salford | A rating |
| Sodick Europe Ltd. | Warwick | A rating |
| SOFAR SOUNDS LIMITED | London | A rating |