| Split-Track Audio Limited | Information & communication | 2005 |
| Splittingup.Com Limited | Professional & scientific | 2019 |
| Sponsorpoint Ltd | Administrative & support | 2026 |
| Sport NE Limited | Arts & recreation | 2013 |
| Sportcomm Limited | Arts & recreation | 2022 |
| Sportfin Limited | Information & communication | 2021 |
| Sporting Chance NE Ltd | Professional & scientific | 2016 |
| Sporting Chance North East C.I.C. | Education | 2016 |
| Sportlink International Ltd | Wholesale & retail | 2025 |
| Sports Management Solutions Limited | Professional & scientific | 2016 |
| Sports Medicine North East Limited | Health & social care | 2013 |
| Sports Press Photo Ltd | Professional & scientific | 2021 |
| SPORTS2 Group Limited | Information & communication | 2021 |
| Sportsmemorabilia.Co.Uk Ltd | Wholesale & retail | 2024 |
| Spot White Ltd | Hospitality | 2016 |
| Spotless Cleaning Services Ltd | Administrative & support | 2026 |
| Spotsense Ltd | Wholesale & retail | 2023 |
| Spray Cork Insulation Limited | Manufacturing | 2025 |
| Spray Solutions N.E. Ltd | Public administration | 2023 |
| Spray Vision & Decorating Ltd | Construction | 2025 |
| Spreckley Limited | Manufacturing | 2001 |
| Sprig and Thistle Ltd | Other services | 2018 |
| Spring 55 Unlimited | Financial services | 2023 |
| Spring Clean Northern Commercial Limited | Administrative & support | 2016 |
| Spring Clean Northern Residential Limited | Administrative & support | 2016 |
| Spring Investment Properties Limited | Real estate | 2023 |
| Spring Leaf Garden Services NE Limited | Administrative & support | 2021 |
| Spring UK Buyer Limited | Financial services | 2024 |
| Springfield Cars Limited | Wholesale & retail | 1988 |
| Springfield Community Association (North Tyneside) Ltd | Other services | 2012 |
| Springfield House Stokesley Management Limited | Real estate | 2007 |
| Springvale EPS Southern Limited | Manufacturing | 2013 |
| Springvale Property Ltd | Real estate | 2017 |
| Springwasted Limited | Real estate | 2003 |
| Springwood Residential Ltd. | Real estate | 2025 |
| Sprinkle Studio Ltd | Hospitality | 2025 |
| Sprinkle's Recovery Project CIC | Health & social care | 2025 |
| Spruce CX Limited | Information & communication | 2012 |
| SPS Microgrids Limited | Professional & scientific | 2022 |
| Spud Gateshead Limited | Hospitality | 2025 |
| Spud Life Chillingham Ltd | Hospitality | 2025 |
| Spudata Ltd | Information & communication | 2026 |
| Spudlife Ltd | Hospitality | 2026 |
| Spuds ‘N’ Sarnies Limited | Hospitality | 2026 |
| Spur Education Ltd | Information & communication | 2025 |
| SPY Group Ltd | Hospitality | 2025 |
| SPY Interiors Ltd | Construction | 2010 |
| SQ Builders Limited | Administrative & support | 2016 |
| Square Box Architecture Ltd | Professional & scientific | 2019 |
| Square One Law LLP | | 2011 |
| Square One Residential Ltd | Real estate | 2018 |
| Squarms Ltd | Information & communication | 2022 |
| Squeezed OUT Early Productions Ltd | Information & communication | 2025 |
| Squidink TAT2 Ltd | Wholesale & retail | 2024 |
| Squires Barnett Architects LLP | | 2011 |
| Squires Capital Limited | Wholesale & retail | 1950 |
| Squires Court (Darlington) RTM Company Limited | Households | 2006 |
| SQUIRREL8 | Financial services | 2013 |
| SR Advice Limited | Administrative & support | 2020 |
| SR Hunton Limited | Extraterritorial | 2020 |
| SR Rail Ltd | Manufacturing | 2018 |
| SR Ways Builders Ltd | Construction | 2025 |
| SR-93 Ltd | Professional & scientific | 2025 |
| SR1892 Ltd | Professional & scientific | 2024 |
| SRA N.E Limited | Real estate | 2024 |
| Sran International Ltd | Wholesale & retail | 2025 |
| SRC BNT Coffee Ltd | Wholesale & retail | 2026 |
| SRC Consultants Ltd | Professional & scientific | 2025 |
| Sree Chem Ltd | Professional & scientific | 2021 |
| SRI Anya Properties Private Limited | Real estate | 2023 |
| SRI Vasavi Kitchen PVT Ltd | Hospitality | 2026 |
| SRI Venkateshwara NCL Limited | Hospitality | 2025 |
| Sridhar Consultancy Ltd | Information & communication | 2024 |
| Srishti IT Solutions Limited | Information & communication | 2018 |
| SRK Broadcast Solutions Ltd | Information & communication | 2024 |
| SRK Taxi Services Ltd | Transport & logistics | 2026 |
| SRM Newcastle Ltd | Hospitality | 2025 |
| SRM Thermoplastic Road Markings Ltd | Construction | 2005 |
| SRR Properties Private Ltd | Real estate | 2024 |
| Srrokebystreet Ltd | Wholesale & retail | 2025 |
| Sruti CIC | Education | 2026 |
| SS Finances NCL Ltd | Real estate | 2025 |
| SS Maan Properties Ltd | Real estate | 2019 |
| SS Retails Stores Ltd | Wholesale & retail | 2025 |
| SS Sunderland Ltd | Hospitality | 2023 |
| SSA Homes & Lettings Ltd | Real estate | 2025 |
| SSB Newcastle Ltd | Other services | 2025 |
| Sscd Property Limited | Real estate | 2022 |
| Ssda Investments Limited | Real estate | 2014 |
| Ssecure Labs Ltd | Information & communication | 2025 |
| SSG Property Limited | Real estate | 2014 |
| SSH Business Services Limited | Administrative & support | 2016 |
| SSH Referrals Ltd | Financial services | 2018 |
| SSM Consultants Limited | Professional & scientific | 2000 |
| SSM PROP2 Ltd | Real estate | 2024 |
| SSN Services Limited | Transport & logistics | 2026 |
| Ssps (NE) Ltd | Construction | 2013 |
| SSR Security Limited | Administrative & support | 2026 |
| Ssrtp Limited | Wholesale & retail | 2018 |
| Sstt Ltd | Wholesale & retail | 2020 |