| Shouri Property Limited | Real estate | 2024 |
| SHR International Group Ltd. | Administrative & support | 2015 |
| SHU PVT Ltd | Wholesale & retail | 2026 |
| Shutt Hardy Properties Ltd | Real estate | 2024 |
| Sicara Trading Company Limited | Wholesale & retail | 2025 |
| Sida Group Ltd | Real estate | 2020 |
| Side Quest Gaming Ltd | Wholesale & retail | 2026 |
| Sidhu Properties NE Ltd | Real estate | 2013 |
| Sidkyan Ltd | Wholesale & retail | 2026 |
| Sierra Delta Limited | Other services | 2001 |
| Sigma Art Ltd | Arts & recreation | 2024 |
| Sign Design (GB) Limited | Manufacturing | 2013 |
| Signature Botanics Wholesale Ltd | Wholesale & retail | 2025 |
| Signature Clean NE Ltd | Administrative & support | 2025 |
| Signature Holdings 7 Ltd | Financial services | 2025 |
| Signature Legal Services Ltd | Financial services | 2021 |
| Signature Sevens Ltd | Wholesale & retail | 2023 |
| Signature Windows & Doors Ltd | Construction | 2019 |
| Signs and Plastic Products, Limited | Manufacturing | 1981 |
| Silk and Blossom Ltd | Arts & recreation | 2021 |
| Silksy Limited | Wholesale & retail | 2021 |
| Silkwood Construction Ltd | Construction | 2025 |
| Silkwood Sourcing Ltd | Real estate | 2025 |
| Silver Cavalry Engineering Ltd | Professional & scientific | 2018 |
| Silver Cloud Limited | Information & communication | 2014 |
| Silver Spur Group Limited | Hospitality | 2026 |
| Silverhaven Limited | Hospitality | 2001 |
| Silvervale Enterprises Limited | Wholesale & retail | 2003 |
| Simchess Ltd | Manufacturing | 2014 |
| Simian Coaching Limited | Information & communication | 2024 |
| Simiden Logistics Ltd | Transport & logistics | 2025 |
| Simlise Developments Ltd | Construction | 2026 |
| Simlise Estates Ltd | Real estate | 2026 |
| Simlise Ltd | Financial services | 2026 |
| Simon Overend Logistics Ltd | Transport & logistics | 2025 |
| Simon Wilkinson Holdings Limited | Wholesale & retail | 2021 |
| Simply Furnishings & Flooring Ltd | Wholesale & retail | 2026 |
| Simpson Housing Ltd | Real estate | 2024 |
| Simpsonpropertyinvestments Limited | Real estate | 2020 |
| Simul Ltd | Real estate | 2025 |
| Singh Enterprises NE Limited | Other services | 2021 |
| Sino Beverages International Ltd | Wholesale & retail | 2025 |
| Sintec Instruments Limited | Professional & scientific | 2013 |
| Siraj Techup Ltd | Information & communication | 2023 |
| Sirona Subsea Limited | Manufacturing | 2022 |
| Site Game Changer Limited | Construction | 2019 |
| SIX Towns Security NE Limited | Administrative & support | 2024 |
| Sixth Star Media Ltd | Information & communication | 2020 |
| SJ Accounting Services (NE) Ltd | Professional & scientific | 2012 |
| SJ Amos Logistics Limited | Transport & logistics | 2025 |
| SJ Consultancy (NE) Ltd | Education | 2020 |
| SJ Investment Group Ltd | Real estate | 2020 |
| SJ Property Renovations Limited | Real estate | 2025 |
| SJB Driveways Limited | Administrative & support | 2025 |
| SJB Landscaping Limited | Administrative & support | 2024 |
| SJB Safety Solutions Limited | Public administration | 2019 |
| SJC Interiors North East Ltd | Construction | 2018 |
| SJD Architects Limited | Professional & scientific | 2003 |
| Sjej Properties Limited | Real estate | 2018 |
| Sjen Engineerng Limited | Wholesale & retail | 2022 |
| SJH Engineering Services Limited | Professional & scientific | 2008 |
| SJJ Electrical Solutions Limited | Construction | 2011 |
| SJM Executive Security Consultancy Ltd | Administrative & support | 2005 |
| Sjones Renovations Ltd | Professional & scientific | 2026 |
| SJT Design Ltd | Construction | 2022 |
| SJT Insight Ltd | Administrative & support | 2015 |
| SJT Northeast Ltd | Health & social care | 2025 |
| Sjtechmed Ltd | Professional & scientific | 2022 |
| SJW Scaff Ltd | Professional & scientific | 2025 |
| SK Motorcycles Limited | Wholesale & retail | 2018 |
| SK Rigging Lifting & Transport Ltd | Mining & quarrying | 2025 |
| Sk(Smart Kaizen) - Pro Auditing, Training and Quality Solutions Ltd | Other services | 2024 |
| Skay Edge Ltd | Information & communication | 2025 |
| Skeeby Engineering Ltd | Professional & scientific | 2026 |
| Skerningham Estates Limited | Real estate | 2017 |
| Skil Global UK Ltd | Information & communication | 2026 |
| Skillcare Academy Ltd | Information & communication | 2025 |
| Skinclin Aesthetics Teesside Limited | Health & social care | 2023 |
| Skinnergate Cycles Stockton Limited | Wholesale & retail | 2007 |
| Skinnovate Aesthetics & Training Academy Ltd | Health & social care | 2020 |
| Skinpharma Limited | Professional & scientific | 2016 |
| Skinrigging Ltd | Construction | 2022 |
| Skins and Needles Beauty Limited | Other services | 2018 |
| Skippy Waste Services Limited | Water & waste | 2015 |
| SKK Enterprises Ltd | Wholesale & retail | 2015 |
| SKT Electrical Ltd | Construction | 2020 |
| SKT Solutions Limited | Information & communication | 2011 |
| SKV Limited | Wholesale & retail | 2002 |
| Sky Higher Digital Limited | Professional & scientific | 2025 |
| Skyla Transport Limited | Transport & logistics | 2023 |
| Skylapse Media Ltd | Professional & scientific | 2018 |
| Skylar Beauty Limited | Other services | 2024 |
| Skyline Taxis Teeside Limited | Wholesale & retail | 2018 |
| SL Pullin Holdings Ltd | Financial services | 2025 |
| Slater Anderson Limited | Professional & scientific | 2003 |
| SLB Recruitment Limited | Administrative & support | 2019 |
| SLD Consulting & Advisory Ltd | Information & communication | 2025 |
| SLD Recycling Limited | Water & waste | 2025 |
| SLH- Construction NE Limited | Construction | 2026 |
| Slinkski Ltd | Manufacturing | 2019 |