| Robinsons Bread and Cake Deliveries Limited | | 1985 |
| Rock Edge Solutions Limited | Information & communication | 2025 |
| Ronda Capital Ltd | Professional & scientific | 2022 |
| Rose N Sharon Limited | Other services | 2010 |
| Roskell Corporation Limited | Extraterritorial | 2000 |
| Rossiter Smith & Co. | Professional & scientific | 2024 |
| ROW Build Limited | Construction | 2006 |
| Rowe One Limited | Information & communication | 2020 |
| Rozee Ltd | Administrative & support | 2021 |
| RTA Instruments Limited | Wholesale & retail | 2006 |
| RTJ Trailers Limited | Transport & logistics | 2005 |
| Rushmere Garden Estate (Ipswich) Limited | Construction | 1956 |
| Rushmere Golf Shop Limited | Wholesale & retail | 2003 |
| Ruth Clarke Qualitative Research Ltd | Professional & scientific | 2013 |
| Rydalbury Limited | Professional & scientific | 1988 |
| Rylands Farm Limited | Agriculture & fishing | 1964 |
| S & C (Car & Commercial) Repairs Limited | Wholesale & retail | 2003 |
| S & V Consultants Limited | Professional & scientific | 2000 |
| S R Renvoize Limited | Professional & scientific | 2002 |
| S&J Star Estates Ltd | Real estate | 2024 |
| S&L Precast Concrete Ltd | Manufacturing | 2026 |
| S. Risby Plumbing & Heating Limited | Construction | 2003 |
| S.E.H. Jackson Limited | Extraterritorial | 2003 |
| S.J.G. Decorators Limited | Administrative & support | 1997 |
| S.W.Loaders Limited | Manufacturing | 2005 |
| S2I Services Ltd | Professional & scientific | 2025 |
| S2SA Ltd | Hospitality | 2023 |
| Sacred Studios Yoga Ltd | Arts & recreation | 2023 |
| Safeguard Investment Corporation Limited | Extraterritorial | 2000 |
| Safeharbor Living Limited | Health & social care | 2024 |
| Safepac Trustees Limited | Professional & scientific | 2003 |
| Safety Champions Limited | Professional & scientific | 2005 |
| Saffron Central Square Tenants' Association | Other services | 2023 |
| Sail and Cover Limited | Manufacturing | 2006 |
| Samuel Property Developments Limited | Real estate | 2026 |
| Sanderson & Sanderson Ltd | Professional & scientific | 2003 |
| Sandpit Systems Limited | Information & communication | 2002 |
| Sandy Paws Suffolk Ltd | Other services | 2024 |
| SANDYS24HEALTHCARE Ltd | Health & social care | 2023 |
| Sangat Sikh Community Association | Education | 2000 |
| Sanya Estates Ltd | Real estate | 2018 |
| Sargasso N1 Limited | Information & communication | 2022 |
| Satin Skinz Ltd | Wholesale & retail | 2023 |
| Saurio Ltd | Wholesale & retail | 2021 |
| Savoury Flavours (Holdings) Limited | Financial services | 2005 |
| Savoury Flavours Limited | Manufacturing | 1999 |
| SB Sales Ltd | Wholesale & retail | 2025 |
| Sbpm Developments Limited | Construction | 2005 |
| Scalelabs Studio Ltd | Information & communication | 2026 |
| Scaleup Tech Ltd | Information & communication | 2023 |
| Schmitt Hausing Limited | Financial services | 2022 |
| Schock Limited | Manufacturing | 2005 |
| School of Heaven Limited | Information & communication | 2024 |
| Scicam Limited | Professional & scientific | 1992 |
| Scish Ltd | Information & communication | 2023 |
| Scotmalt Limited | Manufacturing | 2003 |
| Seafield Property Limited | Financial services | 2021 |
| Seafield SA Management Ltd | Hospitality | 2022 |
| Seago & Stopps Limited | Professional & scientific | 2002 |
| Seamark Nunn Limited | Wholesale & retail | 2003 |
| Sean Hegarty Limited | Construction | 1982 |
| Security Alarm Systems Limited | Arts & recreation | 1991 |
| Seletar Signs Limited | Manufacturing | 2002 |
| Sellout Ltd | Information & communication | 2021 |
| SEN Mamas CIC | Health & social care | 2024 |
| Seraphinbeauty Ltd | Wholesale & retail | 2025 |
| Serenity for Girls CIC | Health & social care | 2023 |
| Serenity Shelfco (NO 4) Limited | Real estate | 2019 |
| SET in Hand Specialist Services Limited | Other services | 1984 |
| SGT. Peppers Restaurants Ltd | Hospitality | 1997 |
| Shades Hairdressing Limited | Other services | 2002 |
| Shakespeare Transport Limited | Transport & logistics | 2002 |
| Sharpley and Regent Insurance Services Limited | Financial services | 1964 |
| SHE Fights Ltd | Arts & recreation | 2026 |
| Sheldrake & Wells Limited | Manufacturing | 1975 |
| Shenqullar Ltd | Wholesale & retail | 2026 |
| Shenry Property Services Ltd | Construction | 2023 |
| Shiena Ltd | Other services | 2024 |
| Shinfield Investments Limited | Extraterritorial | 2002 |
| Shotter & Byers Equine Limited | Professional & scientific | 2025 |
| Siddeeqoon Success Limited | Information & communication | 2024 |
| Sign 24 Limited | Manufacturing | 2007 |
| Silvertree Solutions Limited | Information & communication | 1998 |
| Silverwings Aviation Limited | Administrative & support | 1997 |
| Simba Seal Ltd | Wholesale & retail | 2025 |
| Simon Hilton Limited | Wholesale & retail | 1998 |
| Simon Kimber Cars Limited | Wholesale & retail | 2007 |
| Simply Cricket Limited | Wholesale & retail | 2012 |
| Simply Shutters Limited | Manufacturing | 2000 |
| SIR Thomas Beecham Trust Limited | Health & social care | 1946 |
| Sixth Domain Ltd | Information & communication | 2012 |
| SJP Construct Ltd | Construction | 2024 |
| SKN Convenience Ltd | Wholesale & retail | 2019 |
| Skye Innovations Limited | Other services | 2020 |
| Skyloom Management Ltd | Professional & scientific | 2023 |
| SLA Property Company Limited | Real estate | 1975 |
| Slavell Corporation Limited | Extraterritorial | 2006 |
| SLW Physiotherapy Limited | Health & social care | 2024 |
| Smart House Decoration Ltd | Other services | 2012 |
| Sminc Limited | Information & communication | 2007 |