| Rumney Property Investments Limited | Real estate | 2021 |
| Russell's Reno Limited | Construction | 2021 |
| Rutland Developments Chislehurst Limited | Construction | 2011 |
| Ruxton Court Management Limited | Households | 1992 |
| Ryder Commercial Ltd | Real estate | 2015 |
| RYE Hill Park Developments Limited | Construction | 2014 |
| RZ Estates Limited | Real estate | 2022 |
| S & D Design and Build Ltd | Construction | 2022 |
| S & G Park Holdings Limited | Financial services | 2022 |
| S & G Parks Limited | Hospitality | 2022 |
| S & G Recruitment Limited | Administrative & support | 1988 |
| S and a Jollof Bowl Limited | Hospitality | 2025 |
| S G Plastering Contractors Limited | Construction | 2004 |
| S W Drywall Limited | Construction | 2011 |
| S Watson Optics Limited | Wholesale & retail | 2025 |
| S.Barnard (London) Limited | Wholesale & retail | 2020 |
| S10 Search Limited | Administrative & support | 2024 |
| SAB Electrical Services Limited | Professional & scientific | 2015 |
| Sades Healthcare Limited | Health & social care | 2022 |
| SAI Associates Limited | Information & communication | 2015 |
| Saint Capital Group Ltd | Information & communication | 2026 |
| Saintcommerce Limited | Wholesale & retail | 2025 |
| Sainthedon Limited | Wholesale & retail | 2026 |
| Saje Pharmaceuticals Ltd | Wholesale & retail | 2023 |
| Salco Trading Ltd | Professional & scientific | 2025 |
| Saltwood Care Properties Ltd | Construction | 2014 |
| SAM Brown Carpentry and Joinery Ltd | Construction | 2023 |
| SAM Peel Limited | Professional & scientific | 2022 |
| Santa Services Ltd | Transport & logistics | 2019 |
| Santilli Limited | Hospitality | 2010 |
| Sarah Bader Design Limited | Arts & recreation | 2014 |
| Sarah Millar Limited | Professional & scientific | 2026 |
| Sargent Mitchell Ltd | Information & communication | 2025 |
| Satellite Telecommunications Limited | Wholesale & retail | 2023 |
| Saunders Bookkeeping Solutions Limited | Professional & scientific | 2025 |
| Savi Trades Ltd | Wholesale & retail | 2024 |
| Savoy House Limited | Health & social care | 2023 |
| Sbca Limited | Professional & scientific | 2026 |
| SBL Cleaning Ltd | Administrative & support | 2023 |
| SBL Sparkle Ltd | Administrative & support | 2023 |
| Scent Susan Ltd | Wholesale & retail | 2023 |
| School Lane Mews (Management) Limited | Construction | 2017 |
| Schot Ltd | Information & communication | 2015 |
| Scobet Limited | Construction | 2025 |
| Scottish Fine Soaps Limited | Manufacturing | 1960 |
| Scrap Bays Limited | Information & communication | 2021 |
| Sd&J Limited | Real estate | 2020 |
| Sddk Limited | Wholesale & retail | 2005 |
| Seamless Travel With Claire Ltd | Administrative & support | 2025 |
| Secose Canine Services Limited | Administrative & support | 2012 |
| Secose Training Limited | Administrative & support | 2010 |
| Security Consultancy Services International Limited | Administrative & support | 2009 |
| Security Consultancy Services Limited | Administrative & support | 2008 |
| Security Consultancy Services Residential Limited | Administrative & support | 2009 |
| Selah Holdings Ltd | Financial services | 2020 |
| Senator Cleaning Limited | Administrative & support | 1986 |
| Senderz Sports Ltd | Manufacturing | 2024 |
| Sentry Protection Ltd | Construction | 2024 |
| Sequoia House Ltd | Households | 1997 |
| Services Support (Cleveland) Holdings Limited | Professional & scientific | 2000 |
| Services Support (Cleveland) Limited | Administrative & support | 2000 |
| Services Support (Gravesend) Holdings Limited | Professional & scientific | 2000 |
| Services Support (Gravesend) Limited | Administrative & support | 2000 |
| Services Support (Manchester) Holdings Limited | Professional & scientific | 2001 |
| Services Support (Manchester) Limited | Administrative & support | 2001 |
| Severus Tech Ltd | Information & communication | 2023 |
| SFN Electrical Services Ltd | Construction | 2019 |
| Shameaud Development Limited | Real estate | 2023 |
| Sharp Tecino Ltd | Professional & scientific | 2025 |
| Shavee Enterprise Ltd | Wholesale & retail | 2020 |
| SHE Performs Limited | Arts & recreation | 2020 |
| Shed Factory Limited | Construction | 2018 |
| Sheffield Schools Services Holdings Limited | Administrative & support | 2000 |
| Shining Glory Ltd | Health & social care | 2020 |
| SHO4FUN Ltd | Financial services | 2020 |
| Shurlock Trading Ltd | Wholesale & retail | 2010 |
| Siamco Ltd. | Financial services | 2003 |
| Sidcup Conservative Club Limited | Hospitality | 2021 |
| Siddons Investments Ltd | Wholesale & retail | 2016 |
| Signs 4 School Limited | Manufacturing | 2025 |
| Sihunni Healthcare Limited | Health & social care | 2015 |
| Silentdiscolondon Ltd | Arts & recreation | 2008 |
| Silverxchange Ltd | Wholesale & retail | 2021 |
| Simonit Solutions Limited | Information & communication | 2004 |
| Sister Loves Limited | Wholesale & retail | 2015 |
| Sisteris Limited | Professional & scientific | 2001 |
| Sitic Services Ltd | Administrative & support | 2026 |
| SIV Retail Ltd | Hospitality | 2025 |
| SJT Contractors South East Limited | Construction | 2021 |
| SK8 Grip Limited | Wholesale & retail | 2021 |
| Skandar Consulting Limited | Information & communication | 2011 |
| Skilton Property Services Limited | Construction | 2011 |
| Skinologist Advanced Treatments Limited | Health & social care | 2023 |
| SL Carpets Limited | Construction | 2016 |
| SLC Solutions UK Limited | Education | 2023 |
| SLH Property Partners Limited | Real estate | 2025 |
| Slhs Van Sales Limited | Transport & logistics | 2005 |
| Slice Street Ltd | Hospitality | 2026 |
| SM Building Limited | Construction | 2025 |
| Smallfish Designs Limited | Wholesale & retail | 1991 |