| Studio 287 (NE) Limited | Other services | 2025 |
| Studio Modus Ltd | Professional & scientific | 2026 |
| Studio Resolve Ltd | Professional & scientific | 2022 |
| Studiworks Ltd | Information & communication | 2021 |
| Studysphere Ltd | Education | 2023 |
| STUFF4LIFE Second Time Ltd | Other services | 2023 |
| Stumar Ltd | Hospitality | 2024 |
| Stupid Good Limited | Financial services | 2025 |
| Stych Asbestos Solutions Limited | Water & waste | 2026 |
| SUB Sea Cutting Limited | Manufacturing | 2008 |
| Subs-Direct Ltd | Wholesale & retail | 2022 |
| Subseaham Ltd | Hospitality | 2019 |
| Subzero (Middlehaven) Ltd | Construction | 2019 |
| Suds Cleaning Services Ltd | Administrative & support | 2017 |
| Sue-Saul and Co Ltd | Hospitality | 2025 |
| Summerfield Financial Services Ltd | Financial services | 2026 |
| Summerhill Consulting Services Limited | Professional & scientific | 2022 |
| Summit Wise Ltd | Wholesale & retail | 2025 |
| Sunburst Services Ltd. | Administrative & support | 2018 |
| Sunderland Auto Limited | Wholesale & retail | 2020 |
| Sundown Leisure Limited | Wholesale & retail | 2025 |
| Suneye Limited | Financial services | 2012 |
| Sunflower Cognitive Therapies Limited | Health & social care | 2016 |
| Sunflower Welfare Ltd | Education | 2011 |
| Sunshine Collective Ltd | Other services | 2025 |
| Super Pizza Star Limited | Hospitality | 2020 |
| Superlative Care Limited | Administrative & support | 2025 |
| Supply Teachers Direct Limited | Education | 2001 |
| Supply Vault North East Ltd | Wholesale & retail | 2024 |
| Sureka Limited | Health & social care | 2018 |
| Surely Digital Ltd | Information & communication | 2025 |
| Surface Cleaning Specialists Ltd | Administrative & support | 2025 |
| Surplus-Connect Ltd | Wholesale & retail | 2011 |
| Surprise Ltd | Manufacturing | 2019 |
| Surtec Ltd | Professional & scientific | 2023 |
| Surveyd Ltd | Professional & scientific | 2024 |
| Surya Narayana Innovations Limited | Hospitality | 2024 |
| Susel and Co Limited | Administrative & support | 1993 |
| Sutton Land Consultants Limited | Professional & scientific | 2014 |
| Suzanne Wilson Beauty Limited | Other services | 2024 |
| Svalinn Medical Technologies Ltd | Professional & scientific | 2025 |
| Svalinn Protection Technologies Ltd | Professional & scientific | 2023 |
| SW Group Ltd | Wholesale & retail | 2024 |
| SW Specialist Cars Limited | Wholesale & retail | 2018 |
| SW Vehicle Solutions Ltd | Other services | 2026 |
| Swain Technology Ltd | Information & communication | 2025 |
| Swainstons Limited | Manufacturing | 2001 |
| Swanbeck Seasonal Pitches Ltd | Hospitality | 2024 |
| Swanson Buck Ltd | Administrative & support | 2022 |
| Sweeper Solutions Ltd | Wholesale & retail | 2014 |
| Swift Products UK Ltd | Manufacturing | 2025 |
| Swifthq Tech Ltd | Information & communication | 2025 |
| Swig Group Ltd | Hospitality | 2018 |
| Swingledger Ltd | Arts & recreation | 2026 |
| Switch (Compliance) Limited | Other services | 2016 |
| Switched on Electrical Services Ltd | Construction | 2022 |
| SWK Driving School Ltd | Education | 2022 |
| Swkw Ltd | Construction | 2023 |
| SWR Engineering Ltd | Professional & scientific | 2025 |
| Sycamore Limited | Professional & scientific | 2003 |
| Synergy FTP Limited | Education | 2008 |
| Synrg Records Ltd | Arts & recreation | 2026 |
| Syntactixs Limited | Professional & scientific | 2014 |
| T C Developments North East Ltd | Professional & scientific | 2001 |
| T D Morton(Norton) Ltd | Wholesale & retail | 2021 |
| T D Serviced Properties Ltd | Real estate | 2024 |
| T E Watson & Co. Limited | Agriculture & fishing | 1982 |
| T M Urban Developments Limited | Construction | 2003 |
| T Nicholas EHS Ltd | Professional & scientific | 2024 |
| T S Carpentry Construction Limited | Construction | 2026 |
| T Stanford Consultancy Ltd | Professional & scientific | 2007 |
| T T Logistics Ltd | Transport & logistics | 2018 |
| T Ward Business Developments Limited | Professional & scientific | 2013 |
| T&C Brown Properties Ltd | Households | 2025 |
| T&D Engineering Ltd | Professional & scientific | 2022 |
| T&M Consultancy Limited | Information & communication | 2025 |
| T&R Group UK Limited | Wholesale & retail | 2017 |
| T&R Jiazu Group LLP | | 2022 |
| T&S Access Limited | Manufacturing | 2026 |
| T&S Home Improvements Ltd | Construction | 2026 |
| T-B-C Recruiting Ltd | Transport & logistics | 2026 |
| T-R Operations Ltd | Construction | 2023 |
| T. G. T. International Limited | Extraterritorial | 2002 |
| T. Lowes Electrical Ltd | Construction | 2022 |
| T.J. Hazell (Engineering Consultants) Limited | Construction | 1979 |
| T.K Holdings Limited | Health & social care | 2025 |
| T.M.G. Joinery (UK) Limited | Construction | 2000 |
| T.P.M. Mcdonagh (Civil Engineering) Limited | Construction | 1973 |
| T.Sharp Construction Ltd | Administrative & support | 2026 |
| T2 Creative Ltd | Professional & scientific | 2025 |
| TA KEE Stockton Ltd | Hospitality | 2025 |
| Taah Ltd | Wholesale & retail | 2015 |
| Tact Therapy Services Limited | Health & social care | 2018 |
| Tadas Building Services Ltd | Construction | 2016 |
| Tailored Inspection Limited | Professional & scientific | 2006 |
| Tailormade Shutters Ltd | Manufacturing | 2016 |
| Takeo Fightwear Limited | Wholesale & retail | 2019 |
| Takhar's Store Limited | Wholesale & retail | 2011 |
| Taking Ground | Other services | 2012 |
| Talbotpub Ltd | Hospitality | 2024 |