| SLM Skegness Ltd | Hospitality | 2018 |
| SLM Venture Ltd | Financial services | 2018 |
| Slough Autos Ltd | Wholesale & retail | 2026 |
| Slough Electric Model Car Spares Ltd | Wholesale & retail | 2021 |
| Slough Supermarket Ltd | Wholesale & retail | 2017 |
| SM Car Specialist Ltd | Manufacturing | 2020 |
| SM Logistics Transport Ltd | Transport & logistics | 2025 |
| SM Mobile Mechanic Ltd | Wholesale & retail | 2019 |
| SM Virk Ltd | Transport & logistics | 2022 |
| SM4 Ltd | Manufacturing | 2025 |
| Smallmart UK Limited | Wholesale & retail | 2022 |
| Smart Bedrooms & Closets Ltd | Construction | 2011 |
| Smart Campus Club Limited | Education | 2015 |
| Smart Commercial Finance Ltd | Financial services | 2021 |
| Smart Dhillon Constructions Limited | Construction | 2025 |
| Smart Everywhere Ltd | Wholesale & retail | 2024 |
| Smart Glazer Limited | Construction | 2019 |
| Smart Graphics Solutions Ltd | Information & communication | 2009 |
| Smart Guard Service Ltd | Financial services | 2021 |
| Smart HJ Property Ltd | Construction | 2024 |
| Smart Home PVT Ltd | Real estate | 2025 |
| Smart Home Solutionz Ltd | Construction | 2024 |
| Smart Hub Retail Ltd | Wholesale & retail | 2025 |
| Smart Kitchen and Bedroom Ltd | Construction | 2015 |
| Smart Mobiles Hub Ltd | Wholesale & retail | 2023 |
| Smart Mobiles Tech Ltd | Wholesale & retail | 2019 |
| Smart Mortgage Group Limited | Financial services | 2003 |
| Smart Stay Homes Ltd | Real estate | 2023 |
| Smart Toilets Supplier Limited | Wholesale & retail | 2025 |
| Smart Wooden Stairs Ltd | Manufacturing | 2018 |
| Smart Worker Ltd | Administrative & support | 2021 |
| Smartchannel Limited | Information & communication | 2013 |
| Smartcleanlucy Ltd | Administrative & support | 2026 |
| Smarteco Heating Ltd | Wholesale & retail | 2025 |
| Smartfone Accessories UK Ltd | Wholesale & retail | 2013 |
| Smartlife Health Ltd | Health & social care | 2023 |
| Smartsteer Ltd | Education | 2024 |
| Smash IT Services Ltd | Information & communication | 2022 |
| Smat Logistics Ltd | Transport & logistics | 2021 |
| Smile Construction Ltd | Construction | 2021 |
| Smith Brother Properties Limited | Real estate | 2025 |
| Smiths House UK Ltd | Real estate | 2015 |
| Smithy Media and Entertainments Limited | Information & communication | 2024 |
| SMK Law Limited | Extraterritorial | 2016 |
| SMK Property Maintenance Ltd | Real estate | 2026 |
| SMO77 Ltd | Construction | 2026 |
| SN Carpets Limited | Construction | 2022 |
| SN Stays Ltd | Real estate | 2025 |
| Snap Retailer Ltd | Wholesale & retail | 2025 |
| Snappy Snaps Hounslow Ltd | Wholesale & retail | 2025 |
| Snappy Snaps Staines Ltd | Wholesale & retail | 2025 |
| Snappy Snaps Woking Ltd | Wholesale & retail | 2025 |
| SNG93 Ltd | Construction | 2025 |
| SNM Venture Limited | Hospitality | 2019 |
| Snodas Consulting Ltd | Information & communication | 2012 |
| Snowdrop Assets Limited | Real estate | 2023 |
| Snowflake Care Ltd | Health & social care | 2017 |
| Snowra Ltd | Wholesale & retail | 2025 |
| SNS Driving Ltd | Administrative & support | 2017 |
| Sobims Limited | Construction | 2006 |
| Social Cues Ltd | Manufacturing | 2024 |
| Social Fibre Logistics UK Ltd | Wholesale & retail | 2020 |
| Society of Nepalese Engineers, UK | Other services | 2012 |
| Society of OUR Lady of Lourdes | Other services | 2001 |
| Sodhi Properties Ltd | Real estate | 2026 |
| Sofoako Ltd | Real estate | 2025 |
| Sohal Roofing & Build Ltd | Construction | 2025 |
| Sohal Services Ltd | Transport & logistics | 2017 |
| Sohlo Media Ltd | Professional & scientific | 2026 |
| Sohnipagh Ltd | Health & social care | 2020 |
| Soho Maison Limited | Wholesale & retail | 2026 |
| Solalights Limited | Information & communication | 2004 |
| Solar Power Group - Fzco Ltd | Construction | 2022 |
| Solasquared Ltd | Wholesale & retail | 2025 |
| Solid Base Construction Ltd | Construction | 2025 |
| Solitaire Weddings Limited | Hospitality | 2012 |
| Solo Automotive & Services Ltd | Wholesale & retail | 2017 |
| Solo AV Limited | Manufacturing | 2016 |
| Solo Spice Limited | Hospitality | 2024 |
| Solomon Properties Management Ltd | Transport & logistics | 2026 |
| Solutions AI Ltd | Information & communication | 2018 |
| Solutions Outfit Consultancy Limited | Administrative & support | 2013 |
| Somali Lessons Ltd | Education | 2021 |
| Somcare Agency Limited | Health & social care | 2015 |
| SOMKEN2026 Limited | Professional & scientific | 2026 |
| Sonaya Caterers Ltd | Hospitality | 2025 |
| Soneil International UK Limited | Manufacturing | 1997 |
| Sonha Properties Limited | Real estate | 2020 |
| Soni Construction Limited | Construction | 2016 |
| Soni Hardware Limited | Wholesale & retail | 2021 |
| Soni Media Ltd | Information & communication | 2020 |
| Soni Property INV Ltd | Real estate | 2022 |
| Soni Property Ltd | Real estate | 2023 |
| SONIK77.CONSTRUCTION Ltd | Construction | 2021 |
| Sons of Khalid Ltd | Wholesale & retail | 2024 |
| Sonu Roofing Limited | Construction | 2020 |
| Sonvic Services Ltd | Wholesale & retail | 2018 |
| Sood Tech Ltd | Information & communication | 2026 |
| Sooyaal Mosque Building Limited | Other services | 2025 |
| Sophia Atlantic Ltd | Transport & logistics | 2015 |