| Sofidel UK Limited | Neath | A rating |
| SOFINA LONDON LIMITED | London | A rating |
| SoftBank Group Capital Limited | London | A rating |
| Softech Rail Limited | Albourne | A rating |
| SoftInWay UK Ltd | Weston-super-Mare | A rating |
| Softserve Systems Limited | London | A rating |
| Software AG (UK) Limited | Derby | A rating |
| Sofyne Active Technology Ltd | London | A rating |
| Soho House Limited | London | A rating |
| Soil Machine Dynamics Limited | Wallsend | A rating |
| Sojern Limited | London | A rating |
| Sojitz Aerospace Corporation | London | A rating |
| Sojitz Global Finance plc | London | A rating |
| Solace Canada | London | A rating |
| Solar Options for Schools Ltd | Halstead | A rating |
| Solarig UK Limited | London | A rating |
| Solarpro Holding PLC | London | A rating |
| SOLARWINDS SOFTWARE UK LIMITED | London | A rating |
| Solax Power UK Limited | Atherstone | A rating |
| Sold Out Sales & Marketing Limited | London | A rating |
| Soldo Software Ltd | London | A rating |
| Solent International Limited | Christchurch | A rating |
| Solid Form Solutions Limited | Edinburgh | A rating |
| Solid State Logic UK Ltd t/a Solid State Logic | Oxford | A rating |
| Solid State Plc | Redditch | A rating |
| Solid Telecommunications Ltd | London | A rating |
| Solifi (UK) Limited | Milton Keynes | A rating |
| Solina Coatings UK Ltd | Biggleswade | A rating |
| Solink (UK) Limited | Birmingham | A rating |
| Sollatek (UK) Ltd | Slough | A rating |
| Solo Sprayers Ltd | Shoeburyness | A rating |
| Solomon Associates Ltd | Farnborough | A rating |
| Solutia UK Ltd | Newport | A rating |
| Solvay Interox Ltd | Warrington | A rating |
| Somewhere Restaurant Limited T/A Parker's | London | A rating |
| Sona Solutions Ltd | London | A rating |
| Sonali Bangladesh UK Ltd | London | A rating |
| Sonangol Offshore Services Ltd | London | A rating |
| Sonardyne International Limited | Yateley | A rating |
| Sonata Software Limited | Brentford | A rating |
| Sonatrach Gas Marketing UK Limited | London | A rating |
| Sonatrach Petroleum Corporation | London | A rating |
| Sonatype UK Limited | London | A rating |
| SONG TRADING U.K. LTD | Cardiff | A rating |
| Sonnedix UK Services Limited | London | A rating |
| Sonoco Metal Packaging UK Limited | Wantage | A rating |
| SONOMATIC LTD. | WARRINGTON | A rating |
| Sonos Experience Ltd | London | A rating |
| Sonovision Limited | Letchworth Garden City | A rating |
| Sonrise Services International Limited | Redhill | A rating |
| Sonrysa Ltd | London | A rating |
| Sony Corporate Services Europe Limited | London | A rating |
| Sony Europe B.V | Weybridge | A rating |
| Sony Europe Limited | Weybridge | A rating |
| Sony Interactive Entertainment Europe Limited | London | A rating |
| Sony Music Entertainment UK Limited | London | A rating |
| Sony/ATV Music Publishing | London | A rating |
| Sopex London Limited | London | A rating |
| SOPHOS LIMITED | Abingdon | A rating |
| Sopra Steria Limited | Newcastle Upon Tyne | A rating |
| SORACOM CORPORATION, LTD. | London | A rating |
| Sordo Madaleno Limited | London | A rating |
| Sotheby's | London | A rating |
| SOTI Ltd | Solihull | A rating |
| Soulbei UK ltd | Hampton | A rating |
| SoulCycle London, Ltd | London | A rating |
| Sound Point Capital Management UK LLP | London | A rating |
| Soundtrap Limited | Warwick | A rating |
| Source Group International Limited | Addlestone | A rating |
| South Hook Gas Company Ltd | London | A rating |
| SOUTH HOOK LNG TERMINAL COMPANY LTD. | Milford Haven | A rating |
| South Pole Group UK Ltd. | London | A rating |
| South Staffordshire Plc | Walsall | A rating |
| Southampton Container Terminals Limited trading as DP World Southampton | Southampton | A rating |
| SOUTHAMPTON FOOTBALL CLUB | SOUTHAMPTON | A rating |
| Southco Manufacturing Limited | Worcester | A rating |
| Southworks UK Ltd | London | A rating |
| Sovereign Pension Services (UK) Ltd | Wirral | A rating |
| Sovos Compliance Limited | Farnborough, Hants | A rating |
| Sovrn UK Limited | London | A rating |
| SPA Business Services Ltd | Uxbridge | A rating |
| Space Doctors Limited | Brighton | A rating |
| Space NK Limited | London | A rating |
| SPAFAX AIRLINE NETWORK LIMITED | London | A rating |
| SPANDEX LTD | BRISTOL | A rating |
| Spark Foundry Limited (Trading as Blue 449) | London | A rating |
| Sparrows Offshore International Group Ltd | Aberdeen | A rating |
| SPARTAN RACE UK OPERATIONS LIMITED | London | A rating |
| SpatialBuzz Limited | Guildford | A rating |
| Spaulding Ridge Advisory UK Limited | London | A rating |
| SPD Development Company Ltd | Bedford | A rating |
| SPEC Engineering Ltd | Leatherhead | A rating |
| Special Melted Products Limited | Sheffield | A rating |
| Specsavers Optical Superstores Limited | Fareham | A rating |
| Spectec Ltd | Old Trafford | A rating |
| Spectos U.K. Ltd. | Coleshill | A rating |
| Spectra Logic Europe Ltd | Bracknell | A rating |
| Spectrum Brands EMEA UK Limited | Nottingham | A rating |
| Spectrum Equity UK, LLP | London | A rating |
| Speed Engineering Solutions Limited | Derby | A rating |
| Speedinvest Ltd | Hastings | A rating |
| Speedloan Finance Ltd | Leicester | A rating |
| Spektr UK Division Limited | London | A rating |
| Spencer Stuart & Associates Limited | London | A rating |
| Spendesk Limited | London | A rating |
| Sperry Marine B.V. UK Branch | New Malden | A rating |
| Spex UK Limited | London | A rating |
| SPEYSIDE DISTILLERS COMPANY LIMITED | Glasgow | A rating |
| Sphera Solutions UK Limited | Stonehaven | A rating |
| Spherea Test & Services Ltd | Christchurch | A rating |
| Spiceworks U.K. Ltd. | London | A rating |
| SpiderRock Platform Services UK Limited | Belfast | A rating |
| Spiecapag SAS UK Branch | Farnborough | A rating |
| SPIG S.P.A. | Ipswich | A rating |
| SPINNAKER CAPITAL LIMITED | LONDON | A rating |
| SPIRAX SARCO LIMITED | CHELTENHAM | A rating |
| Spire Global UK Limited | Glasgow | A rating |
| Spirit Energy Production UK Limited | Windsor | A rating |
| Splash Business Intelligence UK Ltd | Brighton | A rating |
| Splend Ltd | London | A rating |
| Spliethoff - BigLift UK Ltd | Westerham | A rating |
| Splitit UK Ltd | London | A rating |
| Sportfive | Altrincham | A rating |
| Sporting Index Ltd | London | A rating |
| SPORTING INSIGHTS LTD | GUILDFORD | A rating |
| Sporting News Enterprises UK Limited | London | A rating |
| Sporting Solutions Services Limited | London | A rating |
| Sportority UK Limited | London | A rating |
| Sportradar UK Limited | London | A rating |
| Sports Entertainment Group (UK) Limited | London | A rating |
| Spotify Limited | London | A rating |
| SPP PUMPS LIMITED | READING | A rating |
| Spreetail UK Limited | Leighton Buzzard | A rating |
| Springer Nature Limited | London | A rating |
| Springer Verlag London Limited | London | A rating |
| Sprinklr UK Ltd | London | A rating |
| Spryker Systems Ltd | Ferndown | A rating |
| SPS UK&I Limited | London | A rating |
| SPS-Providea Limited | HIGH WYCOMBE | A rating |
| Spur Value Partners Ltd | London | A rating |
| SPX Flow Europe Ltd | Cheadle Hulme | A rating |
| SPX International Asset Management Ltd. | London | A rating |
| Square Enix Ltd | London | A rating |
| Squarepoint Capital LLP | London | A rating |
| Squarespace UK Limited | London | A rating |
| SquareTrade Limited | London | A rating |
| Squareup (UK) Ltd | London | A rating |
| SquareUp International Services Ltd | London | A rating |
| Squire Patton Boggs (UK) LLP | London | A rating |
| Squire Technologies Ltd | Dorchester | A rating |
| Squiz (UK) Ltd | London | A rating |
| SriLankan Airlines Limited | Isleworth | A rating |
| SRK Consulting (Kazakhstan) Limited | Cardiff | A rating |
| SRK Consulting (UK) Ltd | Cardiff | A rating |
| SRM Tech Solutions Limited | Watford | A rating |
| SRO Motorsports Europe Ltd | London | A rating |
| SRS Acquiom Holdings UK Ltd | London | A rating |
| SRS Investment Management UK Limited | London | A rating |
| SS and C Financial Services Limited | London | A rating |
| SS&C Financial Services International Limited | Basildon | A rating |
| SS&C Solutions Limited | London | A rating |
| SSA & Company Consulting UK Limited | London | A rating |
| SSANGYONG ENGINEERING & CONSTRUCTION UK LTD. | Middlesbrough | A rating |
| SSP Ltd | Halifax | A rating |
| ST Engineering iDirect (UK) Limited | Milton Keynes | A rating |
| ST Engineering RHQ Limited | Oxon | A rating |
| St James Court Hotel Ltd | London | A rating |
| St Martins Management Corporation Limited | London | A rating |
| St. Cloud State University | Alnwick | A rating |
| St. James's Place plc | Cirencester | A rating |
| Stability AI Ltd | London | A rating |
| Stabilo UK Limited | Dunstable | A rating |
| STACK Infrastructure EMEA Limited | London | A rating |
| Stack Overflow Ltd | London | A rating |
| STACK SPORTS UK LIMITED | Manchester | A rating |
| StackAdapt UK Limited | London | A rating |
| Stacks AI Limited | London | A rating |
| Stadco Limited | Telford | A rating |
| Stadler Rail Service UK Ltd | Liverpool | A rating |
| Staffgroup International Limited | London | A rating |
| Stagecoach Holdings Limited | Perth | A rating |
| Stagwell Media (NRG) UK Limited | London | A rating |
| Standard Advisory London Limited | London | A rating |
| Standard Chartered Bank | London | A rating |
| Standardair Limited | Marlow | A rating |
| Standish Management UK Limited | London | A rating |
| Stanley Consultants, Inc | Suton | A rating |
| Stanley Electric (U.K.) Company Limited | Bracknell | A rating |
| Stanleybet Holdings Limited and Subsidiary Companies | LIVERPOOL | A rating |
| Stantec UK Ltd | Warrington | A rating |
| Stanton House Limited | London | A rating |
| STAR ENERGY GROUP LTD | SUDBROOKE | A rating |
| Star Micronics Europe Ltd | Aylesbury | A rating |
| Star Micronics GB Limited | Derby | A rating |
| STAR TOURS LTD | WEMBLEY | A rating |
| Starbucks Coffee Company (UK) Limited | London | A rating |
| Starbucks EMEA Ltd | London | A rating |
| Starburst Data UK Limited | Bicester | A rating |
| Starcom Worldwide Ltd | London | A rating |
| STARION UK LIMITED | Bath | A rating |