| SYSPRO GLOBAL SOFTWARE LIMITED | London | A rating |
| Systal Technology Solutions | Glasgow | A rating |
| System 2 Capital LLP | London | A rating |
| System Building Services Ltd | Brentwood | A rating |
| System C Healthcare Ltd | Maidstone | A rating |
| SYSTEM ENGINEERING CONSULTING LIMITED | West Sussex | A rating |
| SYSTEM FORCE I.T. LIMITED | Gloucester | A rating |
| System Hydraulics Ltd | CARLISLE | A rating |
| System Laboratories UK Limited | Leighton Buzzard | A rating |
| System Loco Ltd | Lancaster | A rating |
| System ltd | Milton Keynes | A rating |
| System1 Group PLC | London | A rating |
| Systemair Ltd | Birmingham | A rating |
| SYSTEMATIC SECURITY LTD | London | A rating |
| Systematic Software Engineering Limited | Farnborough | A rating |
| Systematica Investments Services Limited | London | A rating |
| SYSTEMATION EURO LTD | NORTHAMPTON | A rating |
| SystemiQ Limited | London | A rating |
| Systemise Ltd | LONDON | A rating |
| SYSTEMRAPID LIMITED | London | A rating |
| SYSTEMS ENTERPRISES LTD | London | A rating |
| Systems iO Limited | Canterbury | A rating |
| Systems IT Support and Consultancy Limited | London | A rating |
| Systems Planning and Analysis UK Limited | Bristol | A rating |
| Systems Technology Consultants Limited | Stoke-on-Trent | A rating |
| SystemsAccountants Limited | Fotheringhay | A rating |
| SystemsDNA Limited | Warlingham | A rating |
| Syston Specsavers Limited | Syston | A rating |
| SYSTRA Ltd | London | A rating |
| SYSVEDA UK LIMITED | LONDON | A rating |
| Sytdaiyl Adult Services T/A Nevin Adult Day Centre | Birmingham | A rating |
| Sytel Limited | Aylesbury | A rating |
| Syzygy Consulting | London | A rating |
| syzygy creatives Ltd | Barking | A rating |
| SZ Catering Ltd t/a The Nawaabs Tandoori | Aberdeen | A rating |
| SZ INNOVATIONS LTD T/A TECH STOP | Alton | A rating |
| SZ Motor Group Ltd | Nottingham | A rating |
| SZ SUPER MARKET LTD | South Humberside | A rating |
| SZA Limited T/A Heavenly Desserts | Newcastle upon tyne | A rating |
| SZABINA SECURITY LTD | Birmingham | A rating |
| Szerelmey Ltd | London | A rating |
| SZS PROPERTIES LTD | London | A rating |