| Spencer Property Management Ltd | Real estate | 2025 |
| Spensley Brothers Limited | Hospitality | 2016 |
| Spice House NE Ltd | Hospitality | 2024 |
| Spice UP Express Ltd | Hospitality | 2024 |
| Spinoff Limited | Health & social care | 2022 |
| Spinzer Logistics & Shipping Line Limited | Transport & logistics | 2024 |
| Spire N E Ltd | Transport & logistics | 2024 |
| Spirit of Captain Cook Limited | Manufacturing | 2017 |
| SPL Electrical (NE) Ltd | Construction | 2022 |
| SPL Properties NE Ltd | Real estate | 2026 |
| Splaine Mechanical Services Limited | Professional & scientific | 2018 |
| Splibre Ltd | Information & communication | 2022 |
| Sports Management International (UK) Limited | Other services | 2009 |
| Spotty Limited | Information & communication | 2025 |
| Spray Direct at Sealpump Limited | Wholesale & retail | 2012 |
| Spraylink UK Ltd | Wholesale & retail | 2023 |
| Spring Kleen Ltd | Administrative & support | 2023 |
| Spring Valley Residential Park Limited | Real estate | 2020 |
| Square Foot Events Limited | Administrative & support | 2018 |
| Square Pizza Salih Ltd | Hospitality | 2019 |
| Square Property Investments Limited | Real estate | 2024 |
| SR Boro Barbers Ltd | Other services | 2026 |
| SR Lifting Services Ltd | Construction | 2024 |
| SR Piping Engineering Ltd | Professional & scientific | 2019 |
| SRB Designing Limited | Professional & scientific | 2012 |
| SRB Vehicles UK Ltd | Wholesale & retail | 2020 |
| Sreekara Retail Limited | Wholesale & retail | 2025 |
| Sreight Estates Ltd | Real estate | 2015 |
| SRG Properties NE Ltd | Real estate | 2026 |
| SRG Services Ltd | Construction | 2026 |
| Srhpc Limited | Professional & scientific | 2025 |
| Sriman Limited | Health & social care | 2019 |
| Srinivasan Medics Ltd | Professional & scientific | 2025 |
| SRJ Retail Stores Limited | Wholesale & retail | 2023 |
| SRJ Rope Techs Ltd | Construction | 2024 |
| SRM Infra Ltd | Construction | 2024 |
| SRN Engineering Ltd | Professional & scientific | 2023 |
| SRP Electrical Engineering Limited | Professional & scientific | 2007 |
| SRP Electrical Services Ltd | Professional & scientific | 2017 |
| SS Contracts Ltd | Construction | 2025 |
| SS Rope Access Limited | Construction | 2023 |
| SSB Bloom Interiors Limited | Construction | 2025 |
| Ssbbmanagement Limited | Administrative & support | 2016 |
| SSC Empire Homes Limited | Real estate | 2016 |
| Ssce Consultancy Limited | Administrative & support | 2007 |
| Ssgt Engineering Limited | Professional & scientific | 2013 |
| SSI Vehicle Services Ltd | Wholesale & retail | 2023 |
| Ssjd Inspections Ltd | Professional & scientific | 2017 |
| Ssjp Engineering Ltd | Mining & quarrying | 2020 |
| SSS ROV Limited | Professional & scientific | 2022 |
| ST & RS Solutions Limited | Wholesale & retail | 2012 |
| ST Hardy Logistics Ltd | Transport & logistics | 2025 |
| ST Judes Residential Home Limited | Health & social care | 2011 |
| ST Judes Residential Home LK Limited | Financial services | 2020 |
| ST Teddy Ltd | Wholesale & retail | 2026 |
| Staccato Marketing Ltd | Professional & scientific | 2026 |
| Stace Distributions Ltd | Wholesale & retail | 2026 |
| Staceys Magic Maids Limited | Administrative & support | 2021 |
| Staconsult Limited | Professional & scientific | 2016 |
| Stadigo Limited | Information & communication | 2021 |
| Stadium Factors Limited | Wholesale & retail | 2018 |
| Stafford & Wilson Limited | Wholesale & retail | 2024 |
| Stag Divisions Ltd | Wholesale & retail | 2004 |
| Stagg Solutions Ltd | Construction | 2025 |
| Stainless Security Services Ltd | Information & communication | 2023 |
| Staithes Community Athletic Club 2021 Ltd | Arts & recreation | 2021 |
| Stallingborough Properties Limited | Energy | 2009 |
| Stallion Consulting and Property Ltd | Construction | 2021 |
| Stallion Solutions Limited | Information & communication | 2023 |
| Stan Services SP. Z O.O. Ltd | Construction | 2025 |
| Standard Property Company NE Ltd | Real estate | 2024 |
| Stanley Investment Properties Ltd | Real estate | 2021 |
| Star Carpets & Flooring Ltd | Wholesale & retail | 2019 |
| Star Gaze Tech Ltd | Wholesale & retail | 2024 |
| Star Plumbing Limited | Construction | 2016 |
| Star Properties Teesside Ltd | Real estate | 2020 |
| Starflex Systems Limited | Wholesale & retail | 2012 |
| Stark Hospitality Ltd | Other services | 2023 |
| Starlight N.E. Ltd | Hospitality | 2021 |
| Stars Orbit Ltd | Real estate | 2024 |
| Start Nest Limited | Wholesale & retail | 2025 |
| Start Safe Stay Safe Ltd | Professional & scientific | 2025 |
| Station Road Solutions Ltd | Wholesale & retail | 2023 |
| Staxton Vale Lodges Limited | Hospitality | 2019 |
| Stayman Property Ltd | Real estate | 2026 |
| Stayte Energy Limited | Energy | 2025 |
| STB Electrical Ltd | Professional & scientific | 2025 |
| STD Engineering Services Limited | Manufacturing | 2002 |
| Steel Benders (UK) Limited | Manufacturing | 2002 |
| Steel Framez Ltd | Extraterritorial | 2023 |
| Steel Property and Garden Services Limited | Other services | 2026 |
| Steel River Academy Trust | Education | 2019 |
| Steel River Business Insurance Ltd | Financial services | 2025 |
| Steel River Power Limited | Energy | 2023 |
| Steel River Quay Limited | Administrative & support | 2023 |
| Steel River Street Food Limited | Hospitality | 2021 |
| Stefan Building Works Ltd | Construction | 2023 |
| Stefan Delivery II Limited | Transport & logistics | 2026 |
| Stefania Services Ltd | Construction | 2021 |
| Stellar Cleaning Ltd | Administrative & support | 2023 |