| Ronansprey Properties Ltd | Real estate | 2026 |
| Rosamond Rebore Services Ltd | Professional & scientific | 2026 |
| Ross Crowe Golf Limited | Wholesale & retail | 2018 |
| Roxburgh Place Ltd | Construction | 2025 |
| Royal Northumberland Yacht Club | Arts & recreation | 2013 |
| RP Demolition Ltd | Construction | 2025 |
| RR Drylining Limited | Construction | 2021 |
| RRS Leisure Limited | Wholesale & retail | 2018 |
| RT Blyth Ltd | Hospitality | 2024 |
| RU Muse Limited | Wholesale & retail | 2025 |
| Rubina Tandoori Limited | Hospitality | 2025 |
| S Mayne Roofing and Property Repairs Ltd | Construction | 2025 |
| S R F H Builders Ltd | Construction | 2024 |
| S T Scaffolding Ltd | Construction | 2011 |
| Safe Stay Homes Ltd | Real estate | 2025 |
| Safeway Scaffold and Access Solutions Ltd | Construction | 2019 |
| Saleem Properties Ltd | Real estate | 2008 |
| Saleems (of) Blyth Ltd | Hospitality | 2021 |
| Salisbury Street Local Stores Ltd | Wholesale & retail | 2025 |
| SAM Castledine Limited | Construction | 2025 |
| Sandhaven Consulting Limited | Professional & scientific | 2026 |
| Sandra Russell Productions Limited | Professional & scientific | 2000 |
| SAR Property Holdings Ltd | Real estate | 2022 |
| Sarah Jane Leisure Ltd | Hospitality | 2025 |
| Saybell Ltd | Health & social care | 2018 |
| Sbcmcbrearty Ltd | Construction | 2026 |
| Scarab 4 Limited | Administrative & support | 2012 |
| Schakley Ltd | Wholesale & retail | 2015 |
| Schumann Investments Limited | Real estate | 2020 |
| Scott Robert Design Limited | Manufacturing | 2015 |
| Seaton Healthcare Limited | Wholesale & retail | 2008 |
| Sensory Pods Limited | Education | 2026 |
| Serenity Willow Ltd | Wholesale & retail | 2022 |
| SGM Plastering & Preservation Ltd | Construction | 2022 |
| Shaka Chakra Ltd | Manufacturing | 2024 |
| Shield Group U.K. Ltd | Professional & scientific | 2019 |
| Shinrai Group Ltd | Wholesale & retail | 2026 |
| Shiotani Automation Services Limited | Professional & scientific | 2025 |
| Shoddy Theatre Ltd | Administrative & support | 2018 |
| Shorelocks Ltd | Other services | 2018 |
| Short Circuit Electrical Solutions Ltd | Professional & scientific | 2010 |
| Sierra Mike Systems Limited | Administrative & support | 2020 |
| Sign (NE) Ltd | Professional & scientific | 2022 |
| Sikhi Juniors FC CIC | Arts & recreation | 2026 |
| Silver Dragonfly Ltd | Real estate | 2018 |
| Silver Lining TM Ltd | Construction | 2022 |
| Simply Fit Kitchens Ltd | Wholesale & retail | 2023 |
| Simply Iberya Ltd | Hospitality | 2025 |
| Simpson PPU Services Ltd | Manufacturing | 2018 |
| Sindhurr Limited | Extraterritorial | 2024 |
| Sing United Limited | Education | 2026 |
| Sizziling Snaggers Ltd | Hospitality | 2019 |
| SJ Heating & Plumbing Services Ltd | Construction | 2022 |
| SJK Leisure Ltd | Hospitality | 2024 |
| SJN Leisure Ltd | Hospitality | 2025 |
| SJT Roofing and Building Ltd | Construction | 2026 |
| Skin 1ST Ltd | Health & social care | 2019 |
| SKYLANE182N Ltd | Administrative & support | 2021 |
| SL Plates Ltd | Manufacturing | 2025 |
| SM Surface Solutions Ltd | Administrative & support | 2026 |
| Smart AS Suit Hire Limited | Other services | 2018 |
| Smash Burger Box Blyth Ltd | Hospitality | 2025 |
| Smash Your Exams Education Ltd | Education | 2024 |
| SML Flooring Ltd | Wholesale & retail | 2015 |
| SN Print and Design Ltd | Manufacturing | 2021 |
| Snaggled Ltd | Wholesale & retail | 2025 |
| Snow Legacy Ltd | Administrative & support | 2026 |
| Sonik Sports Holdings Limited | Financial services | 2026 |
| Sonik Sports Limited | Manufacturing | 2007 |
| SONO24 Ltd | Real estate | 2024 |
| South Beach Convenience Store Blyth Ltd | Wholesale & retail | 2026 |
| Spartan Powered Access Ltd | Manufacturing | 2025 |
| Spartan Spice Ltd | Hospitality | 2018 |
| Specialist Coatings North East Ltd | Manufacturing | 2025 |
| Spencer Court Management (Blyth) Limited | Real estate | 2021 |
| Sperare Limited | Health & social care | 2024 |
| Sprout Collective Limited | Information & communication | 2025 |
| SS Landscaping Ltd | Agriculture & fishing | 2026 |
| SS Testing Projects Ltd | Information & communication | 2016 |
| Ss&Mk Property Ltd | Real estate | 2025 |
| ST Clair Veterinary Care Ltd | Professional & scientific | 2012 |
| ST Edmunds Leisure Limited | Hospitality | 2023 |
| Stan Hunter Haulage Limited | Transport & logistics | 1999 |
| Standard Security Services Limited | Administrative & support | 2003 |
| Statley Trees Limited | Extraterritorial | 2007 |
| Steadihands Ltd | Education | 2025 |
| Stephen Brown Funeral Services Ltd | Other services | 2019 |
| Stevian Ltd | Hospitality | 2023 |
| Stillhue Limited | Professional & scientific | 2026 |
| Stonelea Business Development Limited | Professional & scientific | 2022 |
| Stoneycroftproperties Ltd | Real estate | 2025 |
| Storey and SON Roofing Ltd | Construction | 2026 |
| Stott Manufacturing Solutions Ltd | Manufacturing | 2017 |
| Style and Craft Barbers Ltd | Other services | 2025 |
| SUB Catering Limited | Hospitality | 2014 |
| Subrideo Solutions Group Ltd | Information & communication | 2016 |
| Success Intergrated Services Limited | Hospitality | 2025 |
| Sufra Properties Limited | Real estate | 2025 |
| Summers Abroad Events Ltd | Administrative & support | 2020 |
| Summers Accommodation Ltd | Administrative & support | 2020 |