| S & K Properties Northern Limited | Real estate | 2020 |
| S a Groundworks and Resin Ltd | Construction | 2025 |
| S Macdonald Offshore Services Ltd | Other services | 2018 |
| S.W Retail & Distribution Ltd | Wholesale & retail | 2025 |
| S2 Projects (NE) Limited | Real estate | 2023 |
| S4M Solutions Ltd | Information & communication | 2019 |
| Sahtein Limited | Hospitality | 2018 |
| Sajjan Properties Ltd | Real estate | 2020 |
| Saleem & Bros Ltd | Hospitality | 2017 |
| Salem Tube and Finning Ltd | Manufacturing | 2024 |
| Sallyghairstudio Limited | Other services | 2025 |
| Saltair Consultancy Limited | Information & communication | 2025 |
| Salto Arts Productions Limited | Arts & recreation | 2017 |
| Salvage NE Ltd | Wholesale & retail | 2025 |
| SAM Guthrie Goalkeeping Ltd | Education | 2025 |
| Sambuca Whitley Bay Ltd | Hospitality | 2017 |
| Sandys Blue Advisory Ltd | Professional & scientific | 2024 |
| Sangha Properties (NE) Limited | Real estate | 2023 |
| Sapphire Decorating Ltd | Construction | 2026 |
| Sapphire T&T Ltd | Manufacturing | 2022 |
| Sara Hall Consulting Limited | Information & communication | 2024 |
| Saramik Ltd | Hospitality | 2026 |
| SAS Transport (Northern) Ltd | Wholesale & retail | 2000 |
| Satellite Insight Ltd | Professional & scientific | 2019 |
| Saturn Stove Installations Ltd | Construction | 2023 |
| Sauma Ltd | Hospitality | 2023 |
| SB Consultancy (NE) Ltd | Administrative & support | 2019 |
| SC Logistics (N.E.) Ltd | Transport & logistics | 2019 |
| SC Maddren Consulting Limited | Professional & scientific | 2020 |
| School Improvement Solutions North East Limited | Education | 2009 |
| Science Centres International Ltd | Professional & scientific | 2017 |
| Scope Building Services Ltd | Construction | 2024 |
| Scott Briggs Limited | Administrative & support | 2023 |
| Scott Holland Consulting Limited | Professional & scientific | 2023 |
| Scott Thomson Projects Limited | Construction | 2004 |
| Scroll Media Limited | Information & communication | 2019 |
| Sea Retreats Ltd | Hospitality | 2021 |
| Seaside Drive Ltd | Professional & scientific | 2019 |
| Seaton Delaval Arts Centre | Arts & recreation | 2007 |
| Seaton Delaval Fast Food Ltd | Hospitality | 2018 |
| Seaton Sluice Community Association | Other services | 2009 |
| Seaweed & Ginger Limited | Hospitality | 2019 |
| Secc Limited | Administrative & support | 2023 |
| Secret Garden Tattoo Ltd | Other services | 2026 |
| Security Systems and Alarms Inspection Board | Administrative & support | 1990 |
| Security Systems Inspectorate Ltd | Extraterritorial | 2022 |
| Seller Turnaround Ltd | Professional & scientific | 2023 |
| Seneca Financial Management Ltd | Professional & scientific | 2025 |
| Sensible Default Ltd | Information & communication | 2025 |
| SEO21 Ltd | Information & communication | 2014 |
| Serenity Occupational Health and Wellbeing Services Ltd | Health & social care | 2021 |
| Seton North Ltd | Information & communication | 2009 |
| Sewing Machine Sales Limited | Extraterritorial | 2016 |
| Seymours Motor Body Repairs Limited | Wholesale & retail | 2002 |
| SG Nuclear Consultancy Ltd | Information & communication | 2023 |
| SG Paintwork Ltd | Wholesale & retail | 2022 |
| SGC Hospitality Ltd | Hospitality | 2024 |
| Shahenshah Whitley Road Ltd | Hospitality | 2022 |
| Shampan Whitley Bay Ltd | Hospitality | 2025 |
| Shanguo Films Ltd. | Information & communication | 2017 |
| Share Hospitality Ltd | Hospitality | 2025 |
| Shawdon Close (Management) Limited | Administrative & support | 1999 |
| Sheen Computers & Mobile Ltd | Other services | 2019 |
| SHF Gym Ltd | Arts & recreation | 2018 |
| Shields Farming Co Ltd | Agriculture & fishing | 2018 |
| Shikara Indian Restaurant Limited | Hospitality | 2023 |
| Shildon Development Centre Community Interest Company | Arts & recreation | 2016 |
| Shilling Properties Limited | Real estate | 2021 |
| Shipley Plastering & Interiors Limited | Construction | 2010 |
| Shoreco Services Limited | Professional & scientific | 2023 |
| Shoreline Beauty Ltd | Wholesale & retail | 2021 |
| Shugar Reay & Associates Limited | Administrative & support | 2015 |
| Shutterstyle Ltd | Wholesale & retail | 2014 |
| SHY Bairn Films Ltd | Information & communication | 2023 |
| SIA Barber Ltd | Other services | 2019 |
| SIA Sign Ltd | Manufacturing | 2026 |
| Signalpath Consulting Ltd | Professional & scientific | 2026 |
| Signature FS Limited | Financial services | 2015 |
| Signature North East Limited | Real estate | 2012 |
| Signature Orangeries Limited | Construction | 2013 |
| SIGNPOST37 Ltd | Professional & scientific | 2023 |
| Silent Waves Retreat Ltd | Hospitality | 2020 |
| Silverkeys Properties Limited | Real estate | 2024 |
| Silversun Property Ltd | Real estate | 2025 |
| SIMO8490 Ltd | Other services | 2022 |
| Simon Gordon and Associates Ltd | Professional & scientific | 2021 |
| Simply WED Bridal Limited | Wholesale & retail | 2019 |
| Simpsons of North Shields Limited | Hospitality | 2018 |
| Sinclair Investment Properties Ltd | Real estate | 2001 |
| Sing and Play With Piccolo Ltd | Information & communication | 2022 |
| Singer Machines Limited | Other services | 2003 |
| Singleton Developments Ltd | Construction | 2019 |
| Sister Siete Limited | Wholesale & retail | 2014 |
| SIT Play Stay Ltd | Other services | 2022 |
| Sitrus London Limited | Financial services | 2019 |
| SJA Services (N.E) Ltd | Construction | 2024 |
| SJH Vending Ltd | Wholesale & retail | 2026 |
| SJS Building and Joinery Limited | Construction | 2020 |
| SJT Wealth Management Ltd | Financial services | 2014 |
| Skibums LLP | | 2006 |