| Sanju IT Services Ltd | Information & communication | 2015 |
| Sankby Investments Ltd | Real estate | 2016 |
| Sankhyastat Data Analytics Limited | Information & communication | 2015 |
| Sansoam Ltd | Information & communication | 2010 |
| Santorini Scientific Ltd | Professional & scientific | 2019 |
| Santoshanova Limited | Professional & scientific | 2024 |
| SAO Paulo Style Ltd | Wholesale & retail | 2025 |
| Saqib Solutions Ltd | Construction | 2024 |
| SAR Prop Limited | Real estate | 2022 |
| Sarah Notman Ltd | Information & communication | 2026 |
| Sardar Ltd | Real estate | 2025 |
| Sardar Roofing Ltd | Construction | 2021 |
| Sarni Pack UK Limited | Wholesale & retail | 2026 |
| Sarthy Technologies Limited | Information & communication | 2011 |
| Sarvintage Ltd | Wholesale & retail | 2026 |
| Satradefocus Ltd | Wholesale & retail | 2019 |
| Saudagur Retail Limited | Wholesale & retail | 2026 |
| Savetime Skip & Grab Ltd | Transport & logistics | 2025 |
| Savory Ltd | Manufacturing | 2025 |
| Sawira Investments LLP | | 2023 |
| Sawira Rentals Limited | Real estate | 2023 |
| Sbahra Properties Ltd | Real estate | 2025 |
| Scale Brands Ltd | Wholesale & retail | 2025 |
| SCG Ace Construct Ltd | Construction | 2024 |
| Schmidt Subsea Consulting Ltd | Mining & quarrying | 2017 |
| Scholar Place Properties Limited | Other services | 1999 |
| Schwarzacher Holdings Limited | Financial services | 2026 |
| Scientific Press Limited | Information & communication | 1949 |
| Scope & Holly Ltd | Other services | 2023 |
| Scottish African Safari Park Limited | Arts & recreation | 1970 |
| Scotts Decorating Services (Staines) Limited | Construction | 2018 |
| SDM Constructions Ltd | Construction | 2015 |
| SDR Finance Limited | Financial services | 2026 |
| Seabourne Forwarding Limited | Transport & logistics | 1980 |
| Seabourne Group Limited | Transport & logistics | 1972 |
| Seabourne Mail Solutions Limited | Other services | 1996 |
| Sealants International Limited | Administrative & support | 1997 |
| Seamless Skin Surgery Ltd | Health & social care | 2026 |
| Seaworthy Marine Services Ltd. | Professional & scientific | 2024 |
| SEC Electric Limited | Construction | 2026 |
| Second Parallel Ltd | Wholesale & retail | 2003 |
| Secure Automation (Ascot) Ltd | Construction | 2020 |
| Secure Space Limited | Information & communication | 2018 |
| Secured Finance Network (Europe) Limited | Other services | 2014 |
| Secured Lets London Ltd | Real estate | 2023 |
| Seed Design Ltd. | Extraterritorial | 2006 |
| Seehra Building & Construction Ltd | Other services | 2023 |
| Segaltech Limited | Wholesale & retail | 2025 |
| Sehmi Ltd | Financial services | 2015 |
| Sensor Detection Ltd | Professional & scientific | 2023 |
| Sentenial Properties Limited | Construction | 2014 |
| SERBAN2003 Ltd | Transport & logistics | 2017 |
| Sercom Limited | Information & communication | 2004 |
| Serenity Bridal Boutique Ltd | Other services | 2021 |
| Serfood Ltd | Hospitality | 2023 |
| Servazon Ltd | Financial services | 2023 |
| Serverfi Ltd | Wholesale & retail | 2019 |
| Seven Heights Foods UK Ltd | Hospitality | 2024 |
| Sevenlions Ltd | Real estate | 2019 |
| SFK Accountancy Limited | Professional & scientific | 2024 |
| Sfwl Ltd | Manufacturing | 2017 |
| SG Hub Ltd | Wholesale & retail | 2024 |
| Shah Consultancy Solution Ltd | Health & social care | 2024 |
| Shaheenrk Ltd | Health & social care | 2024 |
| Shaker Investment Limited | Administrative & support | 2010 |
| Shakti 172 Ltd | Real estate | 2018 |
| Shalom Children's Home Care Ltd | Health & social care | 2025 |
| Shalom RAV Ltd | Administrative & support | 2018 |
| Shanaya Malhotra Properties Ltd | Real estate | 2024 |
| Shanghai Meets Taiwan Limited | Hospitality | 2022 |
| Sharmatech Limited | Information & communication | 2018 |
| Shauk Limited | Health & social care | 2016 |
| Shavanti Ltd | Wholesale & retail | 2020 |
| SHE Creates Ltd | Information & communication | 2016 |
| Sheep Walk Academy Limited | Other services | 2023 |
| Shellman Ltd | Construction | 2026 |
| Shera Building Works Ltd | Construction | 2024 |
| Sherston Limited | Hospitality | 2013 |
| Sheza Services Ltd | Transport & logistics | 2018 |
| Shieldcoast Limited | Professional & scientific | 2019 |
| Shift Commerce Limited | Wholesale & retail | 2026 |
| Shine & Align Life Coaching Ltd | Professional & scientific | 2026 |
| Shishirts Ltd | Wholesale & retail | 2021 |
| Shiwa Optical Ltd | Health & social care | 2024 |
| Shojanda Ltd | Professional & scientific | 2021 |
| Short and Sons Accountants Ltd | Professional & scientific | 2017 |
| Shovlin Creative Ltd | Arts & recreation | 2016 |
| Showbiz Global Ltd | Arts & recreation | 2023 |
| Showcase Hire Limited | Administrative & support | 2024 |
| Shreedhar Private Limited | Administrative & support | 2011 |
| Shreem Brzee Ltd | Professional & scientific | 2018 |
| Shreemm Brzee Properties Ltd | Real estate | 2019 |
| Shrusam Tech Limited | Information & communication | 2016 |
| Sidekick Coffee Ltd | Manufacturing | 2024 |
| Sigma Pro Invest Ltd | Real estate | 2025 |
| Sigma Productions Limited | Information & communication | 2021 |
| Sign Media Limited | Professional & scientific | 2010 |
| Signature Pulls Limited | Wholesale & retail | 2025 |
| Signaturecuts Studio Ltd | Professional & scientific | 2025 |
| Silent NO More Limited | Professional & scientific | 2022 |