| Sangarm Property Limited | Real estate | 2019 |
| Sanjay Consulting Services Limited | Information & communication | 2014 |
| Sankhya Limited | Real estate | 2023 |
| Sankofa Corporation Limited | Financial services | 2016 |
| Sankofa Healthcare Ltd | Health & social care | 2025 |
| Sansiri Ltd | Wholesale & retail | 2019 |
| Santini Nights Limited | Administrative & support | 2026 |
| Santinos Club Ltd | Wholesale & retail | 2023 |
| Santrion Group Limited | Financial services | 2025 |
| Sanu Properties Ltd | Real estate | 2019 |
| Sanvi Infotech Limited | Information & communication | 2025 |
| SAO Paulo Import Export (U.K.) Limited | Information & communication | 1989 |
| SAP SCM Limited | Information & communication | 2015 |
| Sapnelis UK Ltd | Wholesale & retail | 2025 |
| Sapp Systems UK Ltd | Professional & scientific | 2025 |
| Sapphire Construction Limited | Construction | 2019 |
| Sapphire Sapphire Construction Ltd | Construction | 2019 |
| Sapphire Traders Ltd | Manufacturing | 2025 |
| Sapphire UK Group Ltd | Hospitality | 2018 |
| Sapphire Wedding Group Ltd | Hospitality | 2018 |
| Saqafat Limited | Wholesale & retail | 2020 |
| Sara KRD Ltd | Wholesale & retail | 2025 |
| Sara Lonsdale Ltd | Construction | 2020 |
| Sara M Limited | Hospitality | 2023 |
| Sarasi Lash & Brows Ltd | Other services | 2019 |
| Saraton Properties Limited | Real estate | 1995 |
| Sarco Consultancy Ltd | Health & social care | 2017 |
| Sargam Music Limited | Information & communication | 2019 |
| Sarika Ventures Ltd | Wholesale & retail | 2026 |
| Saroj Hospitality Ltd | Hospitality | 2019 |
| Sarp Technologies Limited | Information & communication | 2015 |
| Sarro&Korba Food Ltd | Hospitality | 2024 |
| SARS4 Construction Ltd | Construction | 2022 |
| Sartaj Deegan Ltd | Professional & scientific | 2018 |
| Saruls Ecom Ltd | Wholesale & retail | 2025 |
| Sarum Enterprises Ltd | Administrative & support | 2020 |
| Sarvott & Miah Ltd | Hospitality | 2025 |
| SAS CMC Ltd | Financial services | 2025 |
| SAS Consultancy Ltd | Professional & scientific | 2022 |
| SAS PCO Rentals Ltd | Administrative & support | 2025 |
| SAS V Construction Ltd | Construction | 2023 |
| Sasha Court Residents Management Company Limited | Households | 2012 |
| Sasirajpawanraj Ltd | Real estate | 2025 |
| Sasisoft Ltd | Information & communication | 2015 |
| Sasqo GEE Ltd | Health & social care | 2022 |
| Sathu R Ltd | Information & communication | 2026 |
| Sathyian Media Ltd | Information & communication | 2023 |
| Satpal Homes Limited | Real estate | 2024 |
| Satsang Sweets Ltd | Wholesale & retail | 2019 |
| Sattar Estates Ltd | Real estate | 2025 |
| Sattva Pure VEG Limited | Hospitality | 2025 |
| Sauce the Party Ltd | Administrative & support | 2025 |
| Sauk Investments Ltd | Real estate | 2021 |
| Saul D Harrison & Sons PLC | Manufacturing | 1947 |
| Saurum Limited | Professional & scientific | 2012 |
| SAV Construct Ltd | Construction | 2017 |
| SAV Plumbing Ltd | Construction | 2023 |
| Savage Music Inc Limited | Arts & recreation | 2018 |
| Savas Construction Ltd | Construction | 2024 |
| Save Wise Ltd | Wholesale & retail | 2022 |
| Savetrack Ltd | Information & communication | 2024 |
| Savings Hive Ltd | Wholesale & retail | 2025 |
| Savo Pierluigi Ltd | Wholesale & retail | 2025 |
| Savoir Faire (UK) Ltd. | Information & communication | 2011 |
| Savoir Noceur Limited | Hospitality | 2024 |
| Savory Eats Ltd | Hospitality | 2025 |
| Savory Sizzle Ltd | Hospitality | 2023 |
| Savour the Slow Ltd | Wholesale & retail | 2025 |
| Savoy Consultancy Limited | Administrative & support | 2019 |
| Saward Holdings Limited | Professional & scientific | 1962 |
| Sawr Ltd | Wholesale & retail | 2025 |
| Saynai Limited | Information & communication | 2016 |
| Sayra Hussain Ltd | Real estate | 2026 |
| SB Construction and Civil Engineering Ltd | Construction | 2019 |
| SB Consultants (London) Ltd | Professional & scientific | 2018 |
| SB Craftbuilt Ltd | Construction | 2025 |
| SB Drywall Limited | Construction | 2024 |
| SB Impex Limited | Transport & logistics | 2009 |
| SB Jewellers London Ltd | Manufacturing | 2025 |
| SB London Limited | Information & communication | 2025 |
| SB Practice Management Consultancy Ltd | Professional & scientific | 2013 |
| SB Removals Van Ltd | Transport & logistics | 2017 |
| SB Thoracic Consultancy Ltd | Health & social care | 2018 |
| SBD Group Associates Limited | Information & communication | 2016 |
| SBH Network Solutions Limited | Information & communication | 2010 |
| SBK Developments Ltd | Real estate | 2018 |
| Sbkaplan Limited | Professional & scientific | 2023 |
| SBM Properties London Limited | Real estate | 2020 |
| SBR Steris Limited | Administrative & support | 2010 |
| SC Realty Ltd | Real estate | 2025 |
| SC SQ Limited | Real estate | 2023 |
| Sc-Nexus Ltd | Wholesale & retail | 2024 |
| SCA Complete Construction Services Ltd | Construction | 2014 |
| Scaffold Singh Ltd | Construction | 2025 |
| Scah Limited | Real estate | 2021 |
| Scaleflo Creative Ltd | Information & communication | 2026 |
| Scalewithcfo Ltd | Professional & scientific | 2023 |
| Scandiwave Digital Limited | Information & communication | 2025 |
| Scanty Ltd | Real estate | 2022 |
| Scarlet Security Services Ltd | Administrative & support | 2024 |