| Smiths Butchers Limited | Wholesale & retail | 2017 |
| Smiths Motor Parts Ltd | Wholesale & retail | 2025 |
| Smiths Systems Ltd | Manufacturing | 2025 |
| Smith’S Joinery Ltd | Construction | 2023 |
| Smoggie Bloom Agency Ltd | Administrative & support | 2024 |
| Smoggie Doggie Daycare Ltd | Other services | 2018 |
| Smoggie Productions Ltd | Information & communication | 2022 |
| Smoggies Limited | Hospitality | 2017 |
| Smoggy Vapes Direct Limited | Wholesale & retail | 2024 |
| SMS (North East ) Ltd | Information & communication | 2015 |
| SMS Inspection Ltd | Professional & scientific | 2022 |
| SMS Tech Ltd | Information & communication | 2023 |
| SMS Technical Ltd | Professional & scientific | 2021 |
| Smss Safety Ltd | Professional & scientific | 2024 |
| SMT Plant Hire Ltd | Administrative & support | 2024 |
| SMT Services (North) Limited | Wholesale & retail | 2016 |
| SN3W Limited | Administrative & support | 2015 |
| SNAX65 Ltd | Hospitality | 2022 |
| Sndremovals Ltd | Transport & logistics | 2024 |
| SNE Care Services Ltd | Health & social care | 2015 |
| Snood Inspection Ltd | Professional & scientific | 2011 |
| Snoozelab Limited | Wholesale & retail | 2025 |
| Snow Beauty Ltd | Other services | 2021 |
| SNP Works Ltd | Manufacturing | 2008 |
| Snrstysa Ltd | Information & communication | 2024 |
| SO IT Consultancy Services Ltd | Information & communication | 2014 |
| So-Mini (Liverpool) Ltd | Wholesale & retail | 2024 |
| So-Mini Ltd | Wholesale & retail | 2022 |
| Social Nesters Ltd | Transport & logistics | 2022 |
| Social Properties Ltd | Real estate | 2022 |
| Social Summit Marketing Ltd | Professional & scientific | 2025 |
| SOCIALREL8 Ltd | Information & communication | 2011 |
| Socialsphere Ltd | Information & communication | 2025 |
| Soemex Ltd | Information & communication | 2026 |
| Sofya Cleaning Ltd | Administrative & support | 2025 |
| Sohal Roadwayz Limited | Transport & logistics | 2026 |
| Solangi Traders Ltd | Wholesale & retail | 2026 |
| Solarmbrouk Ltd | Other services | 2023 |
| Solec Electrical Services Ltd | Construction | 2022 |
| Solees Travel Ltd | Transport & logistics | 2026 |
| Solid Bond Property Limited | Real estate | 2024 |
| Solm Services Ltd | Construction | 2022 |
| Solmek Holdings Limited | Professional & scientific | 2020 |
| Solomon Construction Limited | Construction | 2017 |
| SOLUTIONS4LOGISITICS Limited | Professional & scientific | 2017 |
| Solve Consultancy Ltd | Extraterritorial | 2023 |
| Solve Process Ltd | Professional & scientific | 2023 |
| Soma Project Controls Ltd | Professional & scientific | 2024 |
| Somane Limited | Public administration | 2022 |
| Somona Barber M Ltd | Other services | 2025 |
| Sonderklasse Limited | Wholesale & retail | 2017 |
| Soneri Ltd | Hospitality | 2026 |
| Sonic Sounds Ltd | Other services | 2026 |
| Sonnee Group Ltd | Transport & logistics | 2023 |
| Sonnys Decoration Services Limited | Construction | 2025 |
| Sopranos Pizza NE Ltd | Hospitality | 2023 |
| Sorcerer Coffee Ltd | Hospitality | 2020 |
| Sorin Ivancea Logistics Limited | Transport & logistics | 2025 |
| SOS Psychological Services Ltd | Professional & scientific | 2025 |
| Soul Clarity for Founders Ltd | Information & communication | 2025 |
| Soul Shine Therapies Limited | Health & social care | 2023 |
| Soundchart Ltd | Information & communication | 2025 |
| Soundz Limited | Information & communication | 2007 |
| Soup Dogg Ltd | Hospitality | 2025 |
| South Bank Insulation Company Limited | Professional & scientific | 1957 |
| South Bank United Football Club Limited | Arts & recreation | 2026 |
| South Manchester Energy Limited | Administrative & support | 2016 |
| South Tees Healthcare Management Limited | Professional & scientific | 2016 |
| South Tees Institute of Learning, Research and Innovation LLP | | 2016 |
| South Tees MX Limited | Other services | 2010 |
| South Thornaby Community Centre CIC | Education | 2019 |
| Southfield Motor Company Limited | Wholesale & retail | 2021 |
| Southfield Retail Ltd | Wholesale & retail | 2024 |
| Southhall Travellers Ltd | Administrative & support | 2025 |
| Southside Broadcasting Limited | Information & communication | 2003 |
| Sowden Properties Limited | Hospitality | 2012 |
| Sowden Property Group Limited | Real estate | 2021 |
| SP Motors NE Limited | Wholesale & retail | 2012 |
| SP NE Ltd | Wholesale & retail | 2012 |
| SP Properties ( North East) Ltd | Real estate | 2025 |
| SP Services and Solutions Ltd | Professional & scientific | 2025 |
| Sp.Hq Rituals Ltd | Wholesale & retail | 2026 |
| SP2 Properties Limited | Real estate | 2015 |
| Spa Well House Limited | Hospitality | 2020 |
| Space Meetings and Events Ltd | Administrative & support | 2019 |
| Space Works Industrial Ltd | Real estate | 2018 |
| Sparkin Engineering Ltd | Mining & quarrying | 2024 |
| Sparkle Tech Ltd | Wholesale & retail | 2024 |
| Sparkle-Wellbeing CIC | Health & social care | 2023 |
| Sparkling With Latifa Ltd | Administrative & support | 2024 |
| SPD Renewable Solutions Ltd | Construction | 2025 |
| Specialist Flooring Supplies Ltd | Wholesale & retail | 2024 |
| Specialist Flooring Tools UK Ltd | Wholesale & retail | 2023 |
| Specialist Hand Car Wash M Ltd | Administrative & support | 2024 |
| Spectrum Consulting (Strategic Business Development) Limited | Professional & scientific | 2010 |
| Spectrum Health & Well-Being Limited | Health & social care | 2019 |
| Spectrum Trade Cars Ltd | Wholesale & retail | 2025 |
| Speedy Plumbing Sales Limited | Wholesale & retail | 2024 |
| Speedza Pizza Ltd | Hospitality | 2023 |
| Spenceley Lettings Ltd | Construction | 2026 |