| S M Properties (Teesside) Limited | Real estate | 2023 |
| S Purvis (Teesside) Ltd | Professional & scientific | 2012 |
| S R Drilling Limited | Construction | 2009 |
| S&A Corporation Ltd | Wholesale & retail | 2025 |
| S&C 360: Fit for Purpose Ltd | Arts & recreation | 2025 |
| S&D Housing Ltd | Real estate | 2019 |
| S&G Argyle Transport Ltd | Transport & logistics | 2026 |
| S&J Kent Construction Services Ltd | Construction | 2025 |
| S&K House of Aesthetics Ltd | Extraterritorial | 2021 |
| S&L Paving Ltd | Construction | 2026 |
| S&R Global Marketing Ltd | Wholesale & retail | 2026 |
| S&R North East Property Development Ltd | Real estate | 2013 |
| S&S Electrics Limited | Construction | 2015 |
| S&S W Consultants Ltd | Professional & scientific | 2026 |
| S&W Rail Cleaning Ltd | Administrative & support | 2024 |
| S. & M.C. Transport Limited | Transport & logistics | 1972 |
| S. and G. Accommodation and Property Limited | Real estate | 1996 |
| S.B Inspections Ltd | Professional & scientific | 2017 |
| S.C. Prodrive Ltd | Construction | 2018 |
| S.M. (Glassenbury) Limited | Arts & recreation | 2013 |
| S.M. (Wrekin) Ltd. | Agriculture & fishing | 2015 |
| S.M. LEM MG Ltd. | Arts & recreation | 2015 |
| S.W.Directional Drilling Ltd | Construction | 2005 |
| S2S Realisations 2026 Limited | Information & communication | 2013 |
| SA Simo Ltd | Hospitality | 2023 |
| Saans Estate Limited | Real estate | 2023 |
| Sabar Industries Limited | Health & social care | 2021 |
| Sackkall Engineering Project Services Ltd | Professional & scientific | 2018 |
| Sacoms Contract Services Ltd | Information & communication | 2018 |
| Sacred Sips Ltd | Manufacturing | 2025 |
| Saddle UP 'N' Dough Ltd | Hospitality | 2026 |
| Sadhu Limited | Transport & logistics | 2006 |
| Sadies Skips Limited | Water & waste | 2009 |
| Sadiq Thornaby Ltd | Health & social care | 2023 |
| Sadlers T/A the Mockingbird Deli & Bistro Ltd | Wholesale & retail | 2018 |
| Safe and Secure Cctv & Alarm Engineers Ltd | Construction | 2025 |
| Safe Phase Electrical Services Ltd | Construction | 2019 |
| Safecheck Ltd | Education | 2025 |
| Safer Communities Limited | Public administration | 1996 |
| Safety & Risk Advisory Ltd | Professional & scientific | 2026 |
| Sage Electrical Services Ltd | Construction | 2026 |
| Sahe Ltd | Real estate | 2024 |
| Saifety Ltd | Professional & scientific | 2023 |
| Saigo Limited | Information & communication | 2024 |
| Sair Property Group Ltd | Real estate | 2025 |
| Saleem Frame Work Limited | Construction | 2023 |
| Sally and Sarah Care Limited | Health & social care | 2013 |
| Sally’S Beauty Lounge Ltd | Other services | 2026 |
| Salmi Ltd | Health & social care | 2020 |
| Salon 54 Ltd | Other services | 2021 |
| Salt and Light Properties Ltd | Real estate | 2024 |
| Saltburn Proctor Ltd | Construction | 2025 |
| Saltburn View Glamping Pods Ltd | Hospitality | 2025 |
| Saltersgill Chippy Ltd | Hospitality | 2022 |
| Saluci Limited | Real estate | 2013 |
| Salus Compliance Ltd | Construction | 2025 |
| Salus Health Ltd | Health & social care | 2014 |
| Salvagehub Ltd | Wholesale & retail | 2025 |
| SAM Babu Limited | Wholesale & retail | 2025 |
| Samridhhifoods Ltd | Wholesale & retail | 2024 |
| Samson Food Group Ltd | Hospitality | 2022 |
| Sanctuary Upholstery Limited | Wholesale & retail | 1989 |
| Sanderson Cars and Parts Ltd | Wholesale & retail | 2025 |
| Sandusky Limited | Manufacturing | 1962 |
| Sandy Kitchen Ltd | Hospitality | 2019 |
| Sanna Solutions Ltd | Administrative & support | 2015 |
| Santos Training & Development Ltd | Professional & scientific | 2015 |
| Sapling Grounds Maintenance Ltd | Administrative & support | 2025 |
| SAR Leisure Limited | Arts & recreation | 2007 |
| Satori Wellness Club Ltd | Other services | 2021 |
| Savage Inspection Ltd | Professional & scientific | 2017 |
| Savage Silk Trustees Limited | Professional & scientific | 2025 |
| Savannah Sheltered Accommodation Ltd | Health & social care | 2021 |
| Savisto Limited | Wholesale & retail | 2014 |
| Sawa Electrical Services Limited | Construction | 2017 |
| Saxon Urban (Five) Limited | Real estate | 2001 |
| SAY YES Adventures Ltd | Administrative & support | 2024 |
| Sayu Limited | Information & communication | 2005 |
| SB Hartlepool Ltd | Professional & scientific | 2012 |
| SB Independent Consultant Ltd | Health & social care | 2026 |
| SBN Properties Ltd | Real estate | 2020 |
| Sbnt Limited | Water & waste | 2008 |
| SC Bricklaying Ltd | Construction | 2024 |
| SC Construction North East Ltd | Construction | 2021 |
| Scarlet Band BUS and Coach Limited | Transport & logistics | 2008 |
| SCB North East Limited | Real estate | 2024 |
| SCG Executive Resilience Limited | Professional & scientific | 2025 |
| Scholarly Limited | Education | 2015 |
| School Diaries Limited | Manufacturing | 2013 |
| Schools OUT Sports in Limited | Arts & recreation | 2017 |
| Scissors CUT Sedgefield Ltd | Other services | 2025 |
| SCL Homes Limited | Real estate | 2023 |
| Scopeblock Limited | Professional & scientific | 1987 |
| Scorgo Coffee & Roastery Co. Ltd | Manufacturing | 2026 |
| Scott Carney Photography Ltd | Professional & scientific | 2012 |
| Scott Leisure Developments Limited | Professional & scientific | 2003 |
| Scott Patterned Concrete Services Ltd | Construction | 2017 |
| Scott Renewables Offshore Services Ltd | Professional & scientific | 2025 |
| Scott Stewart - MAN in the Mirror Ltd | Other services | 2024 |
| Scott Walker Ltd | Construction | 2015 |