| Shivay Foods UK Ltd | Hospitality | 2024 |
| Shivraj Limited | Real estate | 2020 |
| Shoman Solutions Limited | Information & communication | 2025 |
| Shoot 2 Score Limited | Administrative & support | 2021 |
| Shopsage Retail Limited | Wholesale & retail | 2025 |
| Shopsense Limited | Wholesale & retail | 2020 |
| Show Squad Ltd | Administrative & support | 2026 |
| SHR Contracts Limited | Construction | 2020 |
| Shree Beauty Ltd | Other services | 2024 |
| Shree Shree Gems Limited | Wholesale & retail | 2026 |
| Shree Vitthal Rukmini UK Community Interest Company | Education | 2025 |
| Shreyas Management Consulting Services Limited | Professional & scientific | 2025 |
| Shrigajanan Infotech Limited | Information & communication | 2011 |
| Shrinathji Trading Limited | Wholesale & retail | 2019 |
| Shrisha IT Services Ltd | Information & communication | 2024 |
| Shrotz Ltd | Real estate | 2022 |
| Shubh Laabh Kitchen Ltd | Hospitality | 2026 |
| Shufu Capital Limited | Professional & scientific | 2024 |
| Shumed Ltd | Health & social care | 2024 |
| Shure Investment Ltd | Real estate | 2023 |
| Shyamadesign.Com Ltd. | Manufacturing | 2014 |
| SID Car Drive Limited | Transport & logistics | 2023 |
| Sidehill Alley Ltd | Wholesale & retail | 2024 |
| SIFT36 Consulting Ltd | Professional & scientific | 2015 |
| Sigil Research Ltd | Information & communication | 2015 |
| Sigma Broadcast Limited | Information & communication | 2003 |
| Sign Wizzard Limited | Professional & scientific | 2011 |
| Signal to Impact Ltd | Professional & scientific | 2026 |
| Signature Construction Solutions Limited | Construction | 2017 |
| Signature Decor Solutions Ltd | Construction | 2024 |
| Signature Performance Cars Ltd | Wholesale & retail | 2020 |
| Signpost Creative Ltd | Professional & scientific | 2022 |
| Signscope Design Limited | Manufacturing | 2023 |
| Signum Sign Studio Ltd | Professional & scientific | 2013 |
| Silesian Properties UK Ltd | Real estate | 2020 |
| Silk Integration Limited | Health & social care | 2026 |
| Silk Street Properties Ltd | Real estate | 2024 |
| Silkface Limited | Arts & recreation | 2022 |
| Silkfull Beauty London Ltd | Wholesale & retail | 2026 |
| Silky Snooze Ltd | Wholesale & retail | 2025 |
| Sillyjokes Limited | Wholesale & retail | 2004 |
| Silsim Limited | Arts & recreation | 2015 |
| Silvawold Ltd | Real estate | 2022 |
| Silver Top Milk Limited | Hospitality | 2017 |
| Silvercrest Associates Limited | Real estate | 1984 |
| Silvercrest Living Limited | Real estate | 2025 |
| Silvergate Capital Partners Ltd | Professional & scientific | 2016 |
| Silverose Limited | Administrative & support | 2017 |
| Silverstone Campers Ltd | Manufacturing | 2025 |
| Silvios 37DST Ltd | Hospitality | 2023 |
| Silvios Coffee Bars Ltd | Hospitality | 2006 |
| Simcom Limited | Information & communication | 1998 |
| Simes Meds Ltd | Administrative & support | 2023 |
| Simon Guntrip Developments Limited | Construction | 2011 |
| Simon Taylor Enterprises Limited | Extraterritorial | 2008 |
| Simon Taylor Furniture Limited | Manufacturing | 1989 |
| Simon Taylor Holdings Limited | Extraterritorial | 2008 |
| Simon Taylor Interiors Limited | Extraterritorial | 2008 |
| Simonds Garage Limited | Real estate | 1963 |
| Simple Energy SPV 100 Limited | Energy | 2015 |
| Simply Alchemy Ltd | Professional & scientific | 2016 |
| Simply Connect Solutions Limited | Information & communication | 2018 |
| Simply Consult Investment Ltd | Real estate | 2021 |
| Simply Fitt Ltd | Arts & recreation | 2022 |
| Simply Laced Limited | Wholesale & retail | 2025 |
| Simpson & Partners (Alarms) Limited | Extraterritorial | 1997 |
| Simpson Fine Art & Photography Limited | Wholesale & retail | 2024 |
| Simtara Ltd | Wholesale & retail | 2025 |
| Simtech Automation Ltd | Manufacturing | 2015 |
| Simtech Invest Limited | Professional & scientific | 2017 |
| Simtech Simulation Techniques Limited | Manufacturing | 1974 |
| Sinclair Gate Limited | Households | 1989 |
| Singh Sonu Ltd | Construction | 2025 |
| Singhtyres Ltd | Wholesale & retail | 2023 |
| Single Mode Networks Ltd | Information & communication | 2024 |
| Sint Twickenham Ltd | Transport & logistics | 2025 |
| Sinus Media Services Ltd | Information & communication | 2025 |
| Sipchaiii Limited | Hospitality | 2024 |
| SIR Alphonso Mango Limited | Manufacturing | 2022 |
| Siragugal Properties Ltd | Real estate | 2025 |
| Sirbu Ltd | Transport & logistics | 2022 |
| Sirch Plant Limited | Hospitality | 2002 |
| Sirch Tools Ltd | Manufacturing | 2009 |
| Sirens Driver Training Limited | Education | 2019 |
| Sirens Driving Academy Ltd | Education | 2008 |
| Sirius Consulting Services Ltd | Information & communication | 2018 |
| Sitenest Ltd | Information & communication | 2024 |
| Sitnier Ltd | Transport & logistics | 2016 |
| Sivas Retail Ltd | Wholesale & retail | 2024 |
| Sivatech Business Solutions Ltd | Administrative & support | 2011 |
| SIX Acres Warborough Management Company Ltd | Households | 2019 |
| Sixth Element Capital LLP | | 2011 |
| Sizzle Shack Takeaway Ltd | Hospitality | 2025 |
| SJ & HEM Holdings Ltd | Financial services | 2025 |
| SJ Site Management Limited | Construction | 2014 |
| SJC Chimney Sweeps and Stoves Aylesbury Ltd | Construction | 2020 |
| SJC Joinery Limited | Construction | 2013 |
| SJD Games Limited | Wholesale & retail | 2009 |
| SJH UK Services Limited | Construction | 2022 |
| SJJ Solutions Ltd | Financial services | 2025 |