| Spran Property Holdings Limited | Construction | 2022 |
| Spread Eagle Logistics Ltd | Transport & logistics | 2025 |
| Sqcdp.Co.Uk Ltd | Information & communication | 2022 |
| Squareface Engineering Ltd | Professional & scientific | 2025 |
| Squirrels UK Limited | Administrative & support | 2007 |
| SR Properties NE Ltd | Real estate | 2024 |
| SRR Stores Limited | Wholesale & retail | 2020 |
| SS Lifestyle Ltd | Wholesale & retail | 2016 |
| Stag Strength Limited | Arts & recreation | 2022 |
| Stage by Stage Interiors Ltd | Professional & scientific | 2025 |
| Stage Your Property Limited | Professional & scientific | 2024 |
| Stanhope(Newcastle Upon Tyne)Cinema Company Limited(The) | Real estate | 1926 |
| Stashbee Ltd | Information & communication | 2016 |
| Stateside Snacks Limited | Hospitality | 2025 |
| Steadfast Wealth Management Limited | Professional & scientific | 2019 |
| Steamer Street Food Limited | Arts & recreation | 2014 |
| Steel Tool Solutions Limited | Manufacturing | 2006 |
| Steerboard Holdings Limited | Financial services | 2019 |
| Stellatus Limited | Administrative & support | 2011 |
| Stem Building Services Ltd | Construction | 2024 |
| Step-On International Ltd | Wholesale & retail | 2016 |
| Steph Edusei Ltd | Administrative & support | 2025 |
| Stephenson Gaming Ltd | Information & communication | 2021 |
| Sterling and Oak Limited | Real estate | 2026 |
| Steve Hayles Consultancy Limited | Administrative & support | 2017 |
| Steve Roberts Ltd | Construction | 2006 |
| Steve Rutter Technical Services Limited | Construction | 2011 |
| Stirling Safety Limited | Health & social care | 2014 |
| Stratum Logic Ltd | Information & communication | 2025 |
| Street Cred Technology Ltd | Information & communication | 2026 |
| Strong ARM Cabling Solutions Ltd | Construction | 2022 |
| Stubbs Industrial Access Ltd | Manufacturing | 2025 |
| Studio 19 Beauty&Fitness Limited | Arts & recreation | 2023 |
| Studio Botez Ltd. | Information & communication | 2015 |
| Studio DAM Ltd | Professional & scientific | 2023 |
| Subsea Management Ltd | Information & communication | 2025 |
| Subsea Marine Engineering Limited | Professional & scientific | 2008 |
| Subsea Marine Technologies Limited | Professional & scientific | 2015 |
| Succorfish Limited | Professional & scientific | 2015 |
| Succorfish Yacht Safety Systems Limited | Information & communication | 2017 |
| Sudfeld Limited | Real estate | 2000 |
| Sue's Cafe Limited | Hospitality | 2021 |
| SUM Place Ltd | Education | 2023 |
| SUMM1966 Services Ltd | Construction | 2019 |
| Sunbridge Childcare Holdings Ltd | Health & social care | 2025 |
| Sunbridge Childcare Ltd | Health & social care | 2019 |
| Sunbridge Estates Ltd | Health & social care | 2025 |
| SUP4 Ltd | Arts & recreation | 2020 |
| Supermax Creative Studios Limited | Information & communication | 2022 |
| Supreme Tutors Limited | Energy | 2024 |
| Sureline Electrical Limited | Construction | 2024 |
| Surete North East Limited | Construction | 2014 |
| Sustainable Feeds Limited | Agriculture & fishing | 2014 |
| Sutcom Limited | Construction | 2014 |
| Suzanne Elderbrant Limited | Administrative & support | 2022 |
| Swan Hospitality Group Limited | Professional & scientific | 2023 |
| SWH Electrical Solutions Ltd | Administrative & support | 2015 |
| SWH Group Limited | Financial services | 2025 |
| Switch Group Limited | Construction | 2019 |
| Switched on HV Ltd | Construction | 2026 |
| Symphony Coatings (North East) Limited | Wholesale & retail | 1996 |
| Synthesis IT Limited | Information & communication | 2003 |
| System & Design Services Limited | Administrative & support | 2011 |
| T Brown Joiners Ltd | Construction | 2019 |
| T R Engineering & Fabrication Services Ltd. | Manufacturing | 2023 |
| T&C Wright Services Limited | Construction | 2018 |
| T.S.T. Process Systems Limited | Manufacturing | 1995 |
| TA Industrial Services Ltd | Construction | 2023 |
| TAA Insights Ltd | Professional & scientific | 2021 |
| Tactical Competitions Ltd | Wholesale & retail | 2026 |
| Taeks Global Ltd | Information & communication | 2024 |
| Taglab Limited | Information & communication | 2023 |
| Tailhail Limited | Transport & logistics | 2020 |
| Tait Podiatry Ltd | Health & social care | 2025 |
| Take 2 Systems Ltd | Information & communication | 2018 |
| Take Part (North East) Community Interest Company | Education | 2017 |
| Takeoff Tools Limited | Information & communication | 2024 |
| Takungoniano Ltd | Health & social care | 2014 |
| Tall OAT Studios Ltd | Information & communication | 2023 |
| Tanline (NE) Ltd | Other services | 2023 |
| Taycrest Chemicals Limited | Extraterritorial | 1970 |
| Taylor & Porter Limited | Professional & scientific | 2022 |
| Taylor Digital Limited | Professional & scientific | 2021 |
| TBF Online Limited | Information & communication | 2015 |
| TBH Rigging and Lifting Limited | Construction | 2017 |
| TC Bakery Limited | Manufacturing | 2026 |
| TDH Heaton Ltd | Hospitality | 2025 |
| Tea Break Training Ltd | Education | 2016 |
| Teah Property Ltd | Construction | 2025 |
| Team Ferguson Gym Ltd | Arts & recreation | 2020 |
| Team Fostering | Health & social care | 2001 |
| Team Fostering North East | Health & social care | 2001 |
| Teatime Tasties Limited | Wholesale & retail | 2000 |
| Tecaz House Limited | Extraterritorial | 2020 |
| Tecaz Limited | Wholesale & retail | 1985 |
| Tech Mole Ltd | Wholesale & retail | 2021 |
| Tech Projects Ltd | Manufacturing | 2024 |
| Technical Design Services Limited | Construction | 2004 |
| Teleship Limited | Transport & logistics | 2023 |
| Telford Consulting Ltd | Information & communication | 2009 |