| SKS Residential Limited | Real estate | 2025 |
| Sky NE Limited | Agriculture & fishing | 2024 |
| Skyblade Access Ltd | Other services | 2022 |
| Sleep Dreams Limited | Wholesale & retail | 2016 |
| SMS Wind Ltd | Construction | 2024 |
| Snaith & Sons Ltd | Real estate | 2026 |
| SNH Homes Limited | Real estate | 2015 |
| Snooker FC Limited | Arts & recreation | 2002 |
| Snow Engineering Limited | Professional & scientific | 2016 |
| SO & SO Hairdressing Ltd | Other services | 2026 |
| SO SO Cushy Limited | Wholesale & retail | 2023 |
| Social Brew Co Ltd | Manufacturing | 2026 |
| Solana Consulting Limited | Professional & scientific | 2025 |
| Solid Form Ltd | Professional & scientific | 2023 |
| Solutions Accounting Ltd | Professional & scientific | 2021 |
| Solved Creative Ltd | Professional & scientific | 2022 |
| Sonel Electrical Ltd | Manufacturing | 2010 |
| Sopra Limited | Hospitality | 2026 |
| Sorento Limited | Other services | 2014 |
| Sourcedbyandrew Ltd | Wholesale & retail | 2025 |
| Southlands Leisure Ltd | Wholesale & retail | 2015 |
| Southlands Motor Company Ltd | Wholesale & retail | 2012 |
| Souvlaki Time Ltd | Hospitality | 2024 |
| Sp-Quest Ltd | Wholesale & retail | 2025 |
| Space @ Limited | Real estate | 2018 |
| Spark Developments Ltd | Construction | 2022 |
| Speaker Agency Limited | Administrative & support | 2018 |
| Specialist Aluminium Services Limited | Professional & scientific | 2015 |
| Spicy HUT Whitley Bay Ltd | Hospitality | 2025 |
| Spirit Sports Equipment Ltd | Wholesale & retail | 2026 |
| Spoors Holdings Ltd | Financial services | 2025 |
| Sport North East Limited | Education | 2022 |
| Sports Saints Ltd | Other services | 2013 |
| Spotlight School of Performing Arts Ltd | Arts & recreation | 2024 |
| Springtide Property Holdings Ltd | Real estate | 2021 |
| Springtide Property Ltd | Real estate | 2020 |
| Springwaite Film Ltd | Administrative & support | 2024 |
| Squall Capital Ltd | Professional & scientific | 2026 |
| Squarebody Ltd | Construction | 2024 |
| Squidgers Baby Swim School Ltd | Education | 2013 |
| SR Treatment Solutions Ltd | Health & social care | 2023 |
| SR5 Limited | Real estate | 2018 |
| SS Global Network Limited | Manufacturing | 2020 |
| SS Healthfoods Limited | Wholesale & retail | 2007 |
| SS Plating & Fabrication Ltd | Manufacturing | 2026 |
| Ssaib Ltd | Administrative & support | 2025 |
| ST John's Court (Forest Hall) Management Company Limited | Households | 2012 |
| Stable Lane Management Limited | Households | 2014 |
| Staiths (Phase 1) Management Company Limited | Households | 2002 |
| Star of the Sea O.S.C. Limited | Education | 2003 |
| Starfreight Services Limited | Extraterritorial | 1989 |
| Starkade Ltd | Information & communication | 2017 |
| Starks Kitchen Limited | Hospitality | 2019 |
| Stars and Stage Ltd | Arts & recreation | 2022 |
| Statler Mind Wellness Ltd | Health & social care | 2024 |
| Stellar Certification Services Limited | Administrative & support | 2026 |
| Stellar Recruitment Group Limited | Administrative & support | 2020 |
| Stellas Sandwich Bar Limited | Hospitality | 2013 |
| Stem Horizons Ltd | Education | 2025 |
| Sterling House Twenty Limited | Real estate | 2025 |
| Steve Bodtenberg Consultancy Limited | Information & communication | 2002 |
| Steve Bolam Financial Planning Limited | Financial services | 2024 |
| Steve Parker Inspections Ltd | Professional & scientific | 2014 |
| Sting Like a BEE Films Limited | Information & communication | 2016 |
| Stock Management LLP | | 2010 |
| Stonebound Solutions Ltd | Information & communication | 2025 |
| Store Fresh Limited | Extraterritorial | 2014 |
| Stothard Education Limited | Education | 2020 |
| Stove FAN Co Ltd | Wholesale & retail | 2024 |
| Stozone Limited | Water & waste | 2014 |
| Strange Angel Publications Ltd | Information & communication | 2023 |
| Strat(Eu)Gy Limited | Professional & scientific | 2023 |
| Stratus Venture Partners Limited | Administrative & support | 2024 |
| Stresstech Engineering Ltd | Professional & scientific | 2024 |
| Striking Image Ltd | Wholesale & retail | 2024 |
| Strongbox Systems Ltd | Information & communication | 2018 |
| Structures of Legacy Limited | Information & communication | 2024 |
| Stuart Bell (Tiling) Limited | Construction | 2003 |
| Stuart Ritchie Tait Limited | Professional & scientific | 2007 |
| Stuart Science Industries Ltd | Professional & scientific | 2024 |
| Studio Two Interiors Limited | Professional & scientific | 2020 |
| Studio Velo Limited | Arts & recreation | 2017 |
| STUDIO2 Multi-Media Limited | Information & communication | 2015 |
| Styled by Tasha Rayne Ltd | Other services | 2024 |
| Succession Ltd | Financial services | 2013 |
| Summit North East Limited | Construction | 2025 |
| Sun Shop UK (Bedlington) Limited | Other services | 2025 |
| Sunday Benjamin Ltd | Wholesale & retail | 2025 |
| Sunshine Psychological Services Ltd | Education | 2021 |
| Super Mahoosive Limited | Information & communication | 2021 |
| Supertouch Tattoo Ltd | Arts & recreation | 2025 |
| Susan Burton Ltd | Other services | 2003 |
| Susan Hunter Property Ltd | Real estate | 2025 |
| Sustainabilityhunter Limited | Professional & scientific | 2020 |
| Sustainable Global Gardens | Extraterritorial | 2006 |
| Suttie Engineering Services Limited | Professional & scientific | 2018 |
| Swaac Limited | Professional & scientific | 2026 |
| Sweet Inspirations (N.E) Ltd | Manufacturing | 2020 |
| Swood Consulting Ltd | Professional & scientific | 2024 |
| Sycamore Partnership Ltd | Wholesale & retail | 2025 |