| Sonda Recruitment Ltd | Administrative & support | 2022 |
| Songlee Limited | Extraterritorial | 1984 |
| Songul Ltd | Wholesale & retail | 2023 |
| Sonna Print Limited | Arts & recreation | 2025 |
| Sonoran Ltd | Wholesale & retail | 2022 |
| Sontari Capital Ltd | Financial services | 2025 |
| Sophia & Roberts Kitchens, Bedrooms and Bathrooms Ltd | Manufacturing | 2020 |
| Sophia Nail & Beauty Limited | Other services | 2020 |
| Sophia Nails Ammanford Limited | Other services | 2023 |
| Sophie's Bakery Ltd | Wholesale & retail | 2023 |
| Sophora Ltd | Wholesale & retail | 2025 |
| Soraia Crystal Ltd | Health & social care | 2022 |
| Sorela Creates Ltd | Hospitality | 2025 |
| Soros Ventures Limited | Health & social care | 2013 |
| SOS Rahimi Ltd | Real estate | 2025 |
| Sotadem Limited | Other services | 2019 |
| Soulden Ltd | Hospitality | 2025 |
| Soulful Street Ltd | Information & communication | 2025 |
| Sound Property 369 Ltd | Real estate | 2024 |
| Soundgate Roofing Limited | Construction | 2021 |
| Sourced Gloucester & Cotswolds Limited | Real estate | 2020 |
| Sources of Needs Ltd | Wholesale & retail | 2023 |
| Sourcing Experts Ltd | Wholesale & retail | 2024 |
| South Down Kebab Ltd | Hospitality | 2026 |
| South East Repointing & Brick Cleaning Limited | Construction | 2020 |
| South Form Studio Ltd | Professional & scientific | 2025 |
| South Westex Limited | Transport & logistics | 2018 |
| Southbury Club Ltd | Hospitality | 2014 |
| Southbury Garages Ltd | Wholesale & retail | 2019 |
| Southbury Snooker Ltd | Hospitality | 2020 |
| Southern Synergy Limited | Wholesale & retail | 1998 |
| Space Box Homes Ltd | Real estate | 2013 |
| Space Technologies Limited | Mining & quarrying | 2020 |
| Spacebuild Building Contractors Ltd | Construction | 2020 |
| Spaniel Sound Ltd | Information & communication | 2024 |
| Spar Coachworks Ltd | Wholesale & retail | 2023 |
| Spark Kitchen Ltd | Hospitality | 2025 |
| Sparkflowuk Ltd | Construction | 2025 |
| Sparkle Kleen Ltd | Administrative & support | 2024 |
| Sparklegloves Ltd | Administrative & support | 2023 |
| Sparkling Painting and Decoration Services Ltd | Other services | 2020 |
| Sparkly Crafts Limited | Arts & recreation | 2017 |
| Sparkzcreations Ltd | Hospitality | 2025 |
| Sparx Care Limited | Health & social care | 2024 |
| Spas 80 Ltd | Administrative & support | 2025 |
| Spayse Ltd | Administrative & support | 2010 |
| Speak & Acquire Ltd | Other services | 2017 |
| Special Class Barber Shop Limited | Other services | 2020 |
| Special Education Classroom Ltd | Education | 2023 |
| Special Voice Limited | Information & communication | 2018 |
| Spectra Consulting Services Ltd | Professional & scientific | 2018 |
| Spectrum Drainage Ltd | Water & waste | 2012 |
| Speedo Pizza Enfield Ltd | Hospitality | 2023 |
| Speedy Auto Key Ltd | Other services | 2021 |
| Speedy Spell Cargo Limited | Transport & logistics | 2022 |
| Speg LG Services Ltd | Health & social care | 2025 |
| Speranza Food Ltd | Hospitality | 2025 |
| SPH Homes Ltd | Real estate | 2025 |
| Spice Barkingside Ltd | Hospitality | 2023 |
| Spice of India Enfield Ltd | Hospitality | 2024 |
| Spice Voyage Limited | Hospitality | 2025 |
| Spicy Lemon London Limited | Wholesale & retail | 2015 |
| Spidermethods Limited | Information & communication | 2001 |
| Spirala Swiadomosci Limited | Education | 2016 |
| Spiritual Steps Ltd | Education | 2011 |
| Splendid Fridge and Air Conditioning Ltd | Construction | 2020 |
| Spog Limited | Information & communication | 2023 |
| Sport & Adventure Travel Limited | Professional & scientific | 1999 |
| Sport & Entertainment Solutions Ltd | Administrative & support | 2018 |
| Sport Horizon UK Ltd | Information & communication | 2022 |
| Sporting Club Digital Limited | Arts & recreation | 2019 |
| Sportsarchivesco Ltd | Administrative & support | 2015 |
| SPREADSHEET123 Limited | Information & communication | 2010 |
| Spring Rails Productions Limited | Information & communication | 2026 |
| Springbest Limited | Real estate | 2017 |
| Springchase Healthcare Ltd | Health & social care | 2025 |
| Springfield Engineering (UK) Ltd | Construction | 2008 |
| Springtouch Group Limited | Health & social care | 2017 |
| Sprowted Ltd | Professional & scientific | 2021 |
| Sprung UP Naturals Ltd | Other services | 2020 |
| Spvr Arcade Ltd | Arts & recreation | 2023 |
| SQ Professional Limited | Wholesale & retail | 2024 |
| SQ Retail Limited | Real estate | 2024 |
| Square Creativa Ltd | Wholesale & retail | 2017 |
| Squared Group Limited | Professional & scientific | 2015 |
| Squircle Security Limited | Information & communication | 2015 |
| SR Aesthetics Clinic Ltd | Other services | 2025 |
| SR Events & Marketing Limited | Arts & recreation | 2018 |
| Sraj Foods UK Ltd | Hospitality | 2015 |
| Sraj Subs Ltd | Hospitality | 2018 |
| SRL Investment Property Ltd | Real estate | 2024 |
| SS Chicken Ltd | Hospitality | 2018 |
| SSA Construction and Consultancy Ltd | Professional & scientific | 2022 |
| SSA Star Care Ltd. | Health & social care | 2019 |
| SSC Secure Transport Ltd | Transport & logistics | 2013 |
| SSG Capital Ltd. | Manufacturing | 2017 |
| Ssjsg Ltd | Health & social care | 2012 |
| Ssmart Build & Design Ltd | Transport & logistics | 2019 |
| Ssmb Clothing Ltd | Wholesale & retail | 2018 |
| SSN Electricals Limited | Construction | 2026 |