| Singh Bless Limited | Transport & logistics | 2025 |
| Siol Investment Company | Financial services | 2022 |
| Sipping Container Ltd | Manufacturing | 2025 |
| Sirius Star Training and Research Ltd | Professional & scientific | 2026 |
| Siroma Ltd | Manufacturing | 2008 |
| Sirona Properties Limited | Real estate | 2026 |
| SIS Fit Ltd | Arts & recreation | 2024 |
| Sisterforce C.I.C. | Education | 2026 |
| SJG Developments (NW) Ltd | Real estate | 2017 |
| SK Autoelectrics Limited | Wholesale & retail | 2022 |
| Skeleton Records Ltd | Extraterritorial | 2022 |
| Skin Kind Organic Wellness Ltd | Wholesale & retail | 2025 |
| Skin ROW Ltd | Hospitality | 2023 |
| SKM Welding Services Limited | Construction | 2026 |
| SKR Services Limited | Manufacturing | 2008 |
| Sky Cirque Movement Therapy CIC | Health & social care | 2024 |
| Skyline Comms Limited | Professional & scientific | 2017 |
| Skylink Export Import PVT Ltd | Wholesale & retail | 2025 |
| Slates and Ladders NW Ltd | Construction | 2025 |
| Sleepy Tooth Limited | Health & social care | 2025 |
| Slinfold Investments Limited | Real estate | 2004 |
| SLL Consulting Limited | Administrative & support | 2014 |
| SM Estates (NW) Limited | Real estate | 2022 |
| Smart Creative Technologies Ltd | Manufacturing | 2018 |
| Smartzap AI Ltd | Information & communication | 2025 |
| Smash & Shake (SM) Limited | Hospitality | 2023 |
| Smashies Smash Burgers Ltd | Hospitality | 2024 |
| SMC Aesthetics Wirral Ltd | Other services | 2025 |
| Smgf Ventures Ltd | Financial services | 2021 |
| Smith Brothers Transport Ltd | Transport & logistics | 2025 |
| Smithdown Delights Limited | Manufacturing | 2025 |
| Smiths Online Ltd | Wholesale & retail | 2023 |
| Smonds Care Ltd | Health & social care | 2014 |
| Snapfix Limited | Extraterritorial | 2008 |
| Snippitz Ltd | Other services | 2011 |
| SNJ Food Limited | Hospitality | 2026 |
| SO Cakes Limited | Wholesale & retail | 2023 |
| SO Much More Operations Ltd | Transport & logistics | 2025 |
| Social Weekender Limited | Administrative & support | 2019 |
| Sodm Ltd | Other services | 2014 |
| Software City Limited | Information & communication | 2008 |
| Solaluna Ltd | Wholesale & retail | 2024 |
| SOLARIS17 Ltd | Professional & scientific | 2022 |
| Sole Survivor Ptsd Support C.I.C. | Health & social care | 2019 |
| Solo the Bakery Ltd | Wholesale & retail | 2026 |
| Sommerset House Limited | Real estate | 2017 |
| Sonas Investment | Financial services | 2022 |
| Songololo Music Limited | Information & communication | 2014 |
| Sonox Technology Ltd | Manufacturing | 2025 |
| Soundfall Industrial Silencers Ltd | Professional & scientific | 2026 |
| Sounds Project - II Ltd | Administrative & support | 2016 |
| Soupi Hand Car Wash Birkenhead Ltd | Administrative & support | 2022 |
| South Dock Terminals Limited | Transport & logistics | 1997 |
| Southport Shore Limited | Real estate | 2016 |
| Southwood Electrical Ltd | Energy | 2014 |
| Spa Design and Build Limited | Manufacturing | 2021 |
| Space to Help | Information & communication | 2020 |
| Space to Help (Birmingham) | Other services | 2020 |
| Space to Help (Central) | Real estate | 2020 |
| Space to Help (Dorchester) | Other services | 2021 |
| Space to Help (East Central) | Other services | 2021 |
| Space to Help (Ipswich) | Real estate | 2020 |
| Space to Help (Lancashire) | Other services | 2021 |
| Space to Help (London) | Other services | 2020 |
| Space to Help (Luton) | Real estate | 2020 |
| Space to Help (Manchester) | Other services | 2020 |
| Space to Help (NE) | Other services | 2020 |
| Space to Help (North) | Real estate | 2020 |
| Space to Help (Rotherham) | Real estate | 2020 |
| Space to Help (S East) | Other services | 2020 |
| Space to Help (Scots) | Information & communication | 2020 |
| Space to Help (South Central) | Other services | 2021 |
| Space to Help (South) | Real estate | 2020 |
| Space to Help (Stockton) | Other services | 2021 |
| Space to Help (SW) | Other services | 2020 |
| Space to Help (Wrexham) | Other services | 2020 |
| Space to Help (Yorkshire) | Real estate | 2020 |
| SPACE4DANCE Limited | Arts & recreation | 2026 |
| Spar Dyffryn Ltd | Wholesale & retail | 2022 |
| Spare RIB Burlesque Festival Liverpool CIC | Arts & recreation | 2026 |
| Spark Youth Ltd | Other services | 2016 |
| Sparkle & Shine Car Wash Limited | Other services | 2026 |
| Spawinmyway Ltd | Arts & recreation | 2025 |
| Special Badge Services Limited | Wholesale & retail | 2025 |
| Specialist Medical Servicing Ltd | Manufacturing | 2025 |
| Spectral Marine Ltd | Information & communication | 2016 |
| Spectrum Fit-Out Ltd | Construction | 2015 |
| Spectrum Property Group Ltd | Real estate | 2017 |
| Speed MAN Manufacturing Limited | Manufacturing | 2020 |
| Speedwear Ltd | Wholesale & retail | 2013 |
| Speedwell Roofing and Construction Ltd | Construction | 2010 |
| Spellbyte Limited | Real estate | 1998 |
| Spider Project Wirral CIC | Other services | 2014 |
| Spillstar Limited | Manufacturing | 2016 |
| Spindrift Court Management Company Limited | Real estate | 1977 |
| Spink Living Limited | Real estate | 2018 |
| SPJ Ecom Ltd | Wholesale & retail | 2019 |
| SPJ Wholesale Ltd | Manufacturing | 2022 |
| SPL Group UK Ltd | Construction | 2022 |
| Sprint Technologies Ltd | Information & communication | 2023 |