| SLR Motor Company Limited | Wholesale & retail | 2011 |
| SLS Buildings Ltd | Real estate | 2019 |
| SLS Consultancy Limited | Construction | 2000 |
| SLT Project Management Services Limited | Other services | 2019 |
| SLV Investments Ltd | Real estate | 2025 |
| Slvrbk Group Limited | Administrative & support | 2024 |
| SLX Financial Limited | Professional & scientific | 2014 |
| SM Consultancy Solutions Ltd | Information & communication | 2019 |
| SM Design & Build Limited | Administrative & support | 2013 |
| SM Engineering Consulting Limited | Professional & scientific | 2016 |
| Sm-Arter Computing Solutions Limited | Professional & scientific | 2017 |
| Small and Mighty Limited | Information & communication | 2018 |
| Small Business Advisory Service (UK) Ltd | Professional & scientific | 2017 |
| Small Screen Heroes Ltd | Administrative & support | 2025 |
| Smart Administrative Solutions Limited | Administrative & support | 2018 |
| Smart Airspray UK Limited | Construction | 2023 |
| Smart Automation Limited | Professional & scientific | 2018 |
| Smart Bathrooms Limited | Wholesale & retail | 1997 |
| Smart Carpets Limited | Wholesale & retail | 1979 |
| Smart City Lighting Ltd | Wholesale & retail | 2023 |
| Smart Electrical Cheshire Ltd | Construction | 2020 |
| Smart Human Resources Ltd | Administrative & support | 2025 |
| Smart North-West Ltd | Real estate | 2016 |
| Smart Process Solutions Limited | Administrative & support | 2007 |
| Smart Repair 2 U Ltd | Wholesale & retail | 2020 |
| Smart Solutions (Warrington) Limited | Wholesale & retail | 2016 |
| Smart Tronix Limited | Administrative & support | 2018 |
| Smartech Engineering Services Limited | Administrative & support | 2014 |
| Smarter and Safer Products Ltd | Other services | 2019 |
| Smarter Driveway Solutions (NW) Limited | Administrative & support | 2013 |
| Smartflow Solutions Limited | Administrative & support | 2016 |
| Smartpress Limited | Information & communication | 2025 |
| Smartsemicontech Ltd | Administrative & support | 2025 |
| Smartway DRY Cleaners Limited | Administrative & support | 2010 |
| Smartwyre Development Services Ltd | Information & communication | 2019 |
| Smash and Ribs Limited | Hospitality | 2025 |
| Smash Burgers Ltd | Hospitality | 2025 |
| Smashed 4 U Limited | Hospitality | 2024 |
| SMB Auto Repairs Ltd | Wholesale & retail | 2022 |
| SMB Automotive Ltd | Wholesale & retail | 2022 |
| SMB Holdings Warrington Ltd | Financial services | 2022 |
| Smbell Ltd | Administrative & support | 2023 |
| SMC (Health & Safety) Consultancy Services Ltd | Administrative & support | 2008 |
| SMC Consulting Group Ltd | Administrative & support | 2025 |
| SMC Estates Limited | Real estate | 2022 |
| SMC Facilities Group Ltd | Administrative & support | 2006 |
| SMC Mortgages Ltd | Financial services | 2025 |
| SMC Serenity Ltd | Administrative & support | 2026 |
| Smethurst Holdings Limited | Real estate | 2018 |
| Smethurst Property Limited | Real estate | 2025 |
| Smethwick Power Limited | Energy | 2014 |
| SMF Training Limited | Administrative & support | 2022 |
| SMH Group Limited | Health & social care | 2016 |
| SMH Support Services Ltd | Professional & scientific | 2020 |
| SMH Thermal Ltd | Construction | 2022 |
| SMI Engineering Limited | Professional & scientific | 2015 |
| Smile Cleaning.Com Limited | Administrative & support | 2013 |
| Smile GP Ltd | Health & social care | 2024 |
| Smile Pharma Ltd | Wholesale & retail | 2020 |
| Smiles and More Limited | Health & social care | 2013 |
| Smilik Projects Limited | Administrative & support | 2013 |
| Smith & Brant Theatricals Limited | Arts & recreation | 2008 |
| Smith and Company (Bedford) Limited | Extraterritorial | 1979 |
| Smithfields Bathroom Company Limited | Construction | 2011 |
| Smithfields Cabinets Limited | Manufacturing | 2019 |
| Smithfields Kitchen Company Ltd | Wholesale & retail | 2007 |
| Smithfields Surfaces Limited | Construction | 2023 |
| Smiths Service Centre Ltd | Wholesale & retail | 2014 |
| Smithy Engineering Ltd | Professional & scientific | 2019 |
| Smithy Property Investments LLP | | 2018 |
| SML Construction Services Limited | Construction | 2007 |
| SML Process Limited | Professional & scientific | 2010 |
| SMM Ninety 8 Ltd | Other services | 2024 |
| Smoke & RYE Limited | Hospitality | 2015 |
| Smokie MOS Warrington Limited | Hospitality | 2026 |
| SMP Renewable Energies Ltd | Administrative & support | 2023 |
| SMRLC2 Limited | Construction | 2024 |
| SMS Design Technologies Ltd | Construction | 2026 |
| SMU Consulting Limited | Administrative & support | 2021 |
| SMW Architects Limited | Professional & scientific | 2010 |
| SMW Financial Services Limited | Professional & scientific | 2024 |
| SN Consultants Limited | Information & communication | 2016 |
| SN1 Interiors Limited | Administrative & support | 2015 |
| Snap UK Limited | Wholesale & retail | 1995 |
| Snapcastercardstrading Limited | Wholesale & retail | 2024 |
| Snazzie Clothing Ltd | Manufacturing | 2018 |
| Snelson Technical Consultants Limited | Professional & scientific | 2025 |
| Snelsonserver Ltd | Information & communication | 2025 |
| Snippit Media Ltd | Manufacturing | 2025 |
| Snippit Mirrors Limited | Manufacturing | 2020 |
| SNM Barbers Ltd | Other services | 2025 |
| Snoove Properties Limited | Real estate | 2026 |
| Snoutwood Trotters Limited | Agriculture & fishing | 2016 |
| Snow (North West) Limited | Real estate | 2013 |
| Snow Graffiti Limited | Professional & scientific | 2022 |
| Snow Group Limited | Construction | 2024 |
| Snow Property (North West) Limited | Real estate | 2025 |
| Snowdrop Equestrian Limited | Wholesale & retail | 2021 |
| Snowdrop Group NW Ltd | Health & social care | 2021 |
| Snowdrop Personalised Products Ltd | Manufacturing | 2022 |