| Smartlin Ltd | Financial services | 2021 |
| Smarttech Locksmiths Ltd | Wholesale & retail | 2022 |
| Smartwait Limited | Administrative & support | 1996 |
| Smarty Automobile Limited | Wholesale & retail | 2024 |
| Smarty Pantz Ltd | Wholesale & retail | 2017 |
| Smash LAB South Ltd | Hospitality | 2026 |
| Smash Projects UK Ltd | Real estate | 2024 |
| Smasher Burger Ltd | Hospitality | 2023 |
| SMB Holdings Limited | Construction | 2016 |
| Smbudd Ltd | Administrative & support | 2025 |
| SMC Furniture Limited | Wholesale & retail | 2024 |
| SMC Lines Limited | Transport & logistics | 2015 |
| SME Accountancy Ltd | Professional & scientific | 2018 |
| SMF Connect Ltd | Information & communication | 2022 |
| SMF Crouch & Co. Limited | Construction | 2003 |
| SMF Systems Ltd | Wholesale & retail | 2022 |
| SMF Trading Ltd | Wholesale & retail | 2022 |
| SMG Security Ltd | Administrative & support | 2024 |
| SMH Build Ltd | Construction | 2026 |
| SMH Estates Holdings Ltd | Real estate | 2025 |
| SMH Henley Limited | Hospitality | 2023 |
| SMH Plumbing and Gasworks Limited | Wholesale & retail | 2007 |
| SMH Plumbing and Heating Ltd | Construction | 2020 |
| SMH Surveyors Ltd | Professional & scientific | 2023 |
| SMI Yacht Coatings Ltd | Construction | 2024 |
| Smigo Ltd | Information & communication | 2010 |
| Smile Care by Victoria Ltd | Health & social care | 2025 |
| Smilen VIP Ltd | Transport & logistics | 2020 |
| Smilerequest Ltd | Health & social care | 2025 |
| Smiles Preschool Ltd | Education | 2026 |
| SMILES4MILESUK Limited | Health & social care | 2014 |
| Smith & Rawlins Ltd | Construction | 2020 |
| Smith & Webb Limited | Construction | 1998 |
| Smith and Franklin Services Limited | Wholesale & retail | 2018 |
| Smith Displays Limited | Manufacturing | 2024 |
| Smith Kids Investments Limited | Real estate | 2017 |
| Smith Serviced Accommodation Limited | Real estate | 2024 |
| Smith's S&T Ltd | Manufacturing | 2011 |
| Smithly Ltd | Transport & logistics | 2025 |
| SMM Sales Commerce Ltd | Wholesale & retail | 2026 |
| Smohs Ltd | Health & social care | 2022 |
| Smoke Convince Limited | Wholesale & retail | 2026 |
| Smoke Vent Systems Ltd | Construction | 2011 |
| Smokey Portswood Ltd | Hospitality | 2019 |
| Smoking Buddha Limited | Manufacturing | 2018 |
| Smoking Hot Ltd | Wholesale & retail | 2018 |
| Smolin Services Ltd | Construction | 2026 |
| SMP Finance Consultancy Ltd | Wholesale & retail | 2026 |
| SMT Pro Limited | Administrative & support | 2024 |
| SMZ Consulting Ltd | Professional & scientific | 2022 |
| SNA Eyecare Limited | Health & social care | 2020 |
| Snaggle Tooth Kirsty Gowman Limited | Other services | 2016 |
| Snap Attax Ltd | Real estate | 2015 |
| Snap Neurodiagnostics Ltd | Health & social care | 2026 |
| SNAP2BTL Ltd | Real estate | 2023 |
| SNAP2HIRE Ltd | Real estate | 2019 |
| Snapback Ltd | Professional & scientific | 2024 |
| Snappie Ltd | Manufacturing | 2023 |
| Snaxu Ltd | Wholesale & retail | 2025 |
| Sneaker Station Ltd | Wholesale & retail | 2025 |
| SNG Property Maintenance Limited | Construction | 2011 |
| SNL Property Limited | Real estate | 2021 |
| Snowdrop Consulting Limited | Administrative & support | 2026 |
| Snowfields Care Limited | Health & social care | 2017 |
| Snowflake Healthcare Ltd | Health & social care | 2022 |
| Snows Business Holdings Limited | Professional & scientific | 1980 |
| Snows Motor Group Limited | Wholesale & retail | 1977 |
| Snozzle TM Limited | Construction | 2017 |
| Snozzwanger Sound Limited | Arts & recreation | 2018 |
| SNR Sons Ltd | Health & social care | 2025 |
| SNS Sravs Kitchen Ltd | Hospitality | 2020 |
| SNT Cleaning Services Ltd | Administrative & support | 2014 |
| Snug Architects Limited | Professional & scientific | 2003 |
| Snug Projects Limited | Real estate | 2014 |
| SO Brew Ltd | Hospitality | 2024 |
| SO Catering (DP) Limited | Hospitality | 2021 |
| SO Ceroc Ltd | Arts & recreation | 2023 |
| SO Creative Marketing Limited | Professional & scientific | 2019 |
| SO Drive Limited | Transport & logistics | 2026 |
| SO Events Limited | Other services | 2022 |
| SO Frank Studio Limited | Professional & scientific | 2025 |
| SO Fresh Cleaning Group Ltd | Administrative & support | 2025 |
| SO FX Limited | Education | 2018 |
| SO Locksmiths Ltd | Administrative & support | 2020 |
| SO Make IT Ltd. | Other services | 2013 |
| SO Perfect Limited | Administrative & support | 2017 |
| SO Procurement Limited | Professional & scientific | 2023 |
| SO Roofing and Building Ltd | Construction | 2025 |
| SO Serviced Stays Ltd | Real estate | 2025 |
| SO Shine Limited | Hospitality | 2022 |
| SO14 Ltd | Other services | 2016 |
| SO18 Limited | Real estate | 2016 |
| SO31 Construction Ltd | Construction | 2018 |
| SO31 Ltd | Manufacturing | 2009 |
| SO40 Ltd | Hospitality | 2020 |
| SO40 Site Management Ltd | Construction | 2014 |
| SO51 Consultancy Limited | Administrative & support | 2017 |
| Soames Developments Ltd | Construction | 2019 |
| Soap & Pawry Ltd | Other services | 2023 |
| Soaring Success Ltd | Professional & scientific | 2022 |