| Sktech Ltd | Information & communication | 2018 |
| Sky Meridian Real Estate Ltd. | Construction | 2014 |
| Sky Vision Trading Ltd | Wholesale & retail | 2016 |
| Skyblue Financial Services Ltd | Financial services | 2016 |
| Skyblue Security Consulting Ltd | Information & communication | 2025 |
| Skyeview Homes Ltd | Real estate | 2025 |
| Skylab Imaging Limited | Professional & scientific | 2017 |
| Skylander Estates Limited | Real estate | 2015 |
| Skyrise Consultancy Limited | Real estate | 2007 |
| Slater Management Limited | Professional & scientific | 2005 |
| Slava Construction Ltd | Construction | 2025 |
| SLC Security Services Ltd | Administrative & support | 2021 |
| Sleepworld Ltd | Other services | 2016 |
| SLF Builders Limited | Construction | 2019 |
| Slink Solutions Ltd | Information & communication | 2025 |
| Slipway Leisure Limited | Hospitality | 2021 |
| SLL Global Living Ltd | Wholesale & retail | 2025 |
| Slough County Property Limited | Real estate | 2025 |
| Slough Estates Limited | Real estate | 2013 |
| Slough Haveli Ltd | Construction | 2020 |
| Slough Skylight LLP | | 2016 |
| Slsr Ltd | Real estate | 2020 |
| SM Advice Limited | Professional & scientific | 2024 |
| SM Commerce Limited | Other services | 2012 |
| Smaaz Ltd | Wholesale & retail | 2020 |
| Small Pouches Limited | Wholesale & retail | 2023 |
| Smart & Sharp Salon Ltd | Other services | 2018 |
| Smart Cabz Ltd | Transport & logistics | 2019 |
| Smart Choice Motors Ltd | Wholesale & retail | 2026 |
| Smart Ethos Ltd | Administrative & support | 2023 |
| Smart Learners School of Motoring Limited | Education | 2013 |
| Smart Life AV Ltd | Other services | 2017 |
| Smart Living Solutions Ltd | Construction | 2005 |
| Smart Property Rental Ltd | Households | 2017 |
| Smart Yellow Bird Marketing Limited | Professional & scientific | 2016 |
| Smartbox Ltd | Wholesale & retail | 2021 |
| Smash Badminton Academy Limited | Arts & recreation | 2023 |
| SME Base Limited | Information & communication | 2013 |
| SME Crowd Ltd | Financial services | 2014 |
| Smgb Trading Ltd | Wholesale & retail | 2022 |
| Smile Arts Studio PVT Ltd | Health & social care | 2011 |
| Smile MH Limited | Health & social care | 2023 |
| Smile PR Limited | Professional & scientific | 2018 |
| Smile Smith Dental Care Limited | Health & social care | 2022 |
| Smiles by RIA Ltd | Health & social care | 2026 |
| Smjm Smiles Ltd | Health & social care | 2023 |
| SML Legal Services Limited | Professional & scientific | 2019 |
| Smmb Property Limited | Real estate | 2017 |
| Smmm Consultancy Limited | Information & communication | 2007 |
| SMV Civils Limited | Construction | 2024 |
| SMV Group Ltd | Professional & scientific | 2021 |
| SMV Real Estate Limited | Real estate | 2021 |
| Snacky Pals Ltd | Wholesale & retail | 2025 |
| Snaps&Racks Ltd | Manufacturing | 2013 |
| Snapsi Ltd | Information & communication | 2023 |
| Snaresbrook Developments Ltd | Real estate | 2022 |
| SNB Accountancy Services Ltd | Professional & scientific | 2018 |
| SNC Collective Ltd | Other services | 2025 |
| Sneakerheadz Limited | Wholesale & retail | 2015 |
| Snoobl Limited | Information & communication | 2023 |
| Snowdon Technology Limited | Information & communication | 2010 |
| SNR Commerce Ltd | Wholesale & retail | 2023 |
| SNS Properties & Investments (UK) Ltd | Real estate | 2021 |
| SNS Trading Limited | Wholesale & retail | 2002 |
| SNV Trade Ltd | Wholesale & retail | 2014 |
| SO True Beauty Ltd | Other services | 2020 |
| Social Forge Limited | Professional & scientific | 2026 |
| Sodaclick Ltd | Information & communication | 2017 |
| Soft Matters Ltd | Information & communication | 2026 |
| Softlink Consultants Limited | Professional & scientific | 2003 |
| Softomate Solutions Limited | Information & communication | 2022 |
| Softpride Systems (Europe) Limited | Information & communication | 2000 |
| Soirella Limited | Other services | 2015 |
| Sokam Properties Limited | Construction | 2015 |
| Sola Sound Limited | Wholesale & retail | 1964 |
| Solage Partners Ltd. | Professional & scientific | 2015 |
| Solar Cosmetics International Limited | Manufacturing | 1996 |
| Solara Concept Studio Ltd | Manufacturing | 2023 |
| Solei Swim Ltd | Wholesale & retail | 2024 |
| Solenso Ltd | Wholesale & retail | 2025 |
| Solid Investments Limited | Real estate | 1983 |
| Solidchange Property Management Limited | Households | 1990 |
| Solihull Horizons Limited | Financial services | 2026 |
| Solihull White House Limited | Health & social care | 2026 |
| Solocopy Limited | Wholesale & retail | 2009 |
| Solomon Bassist Limited | Professional & scientific | 2018 |
| Solomon Bassist Properties Ltd | Real estate | 2021 |
| Solomon Care Limited | Health & social care | 2021 |
| Solomon Tax Limited | Professional & scientific | 2012 |
| Solomon's Grooming Room Limited | Other services | 2022 |
| Solomon’S Building & Maintenance Limited | Construction | 2021 |
| Somak DMC Limited | Administrative & support | 2022 |
| Some Estates Ltd | Real estate | 2022 |
| SOMERSET9 Limited | Construction | 2020 |
| Sona IT Ltd | Information & communication | 2014 |
| Sonam Shah Limited | Real estate | 2016 |
| Sonar Sight Co Ltd | Information & communication | 2024 |
| Sonhen UK Ltd | Wholesale & retail | 2024 |
| Sonigra Medical Limited | Health & social care | 2008 |
| Sonisha Ltd | Real estate | 2025 |