| Shangri-La Domestic & Commercial Cleaning Limited | Administrative & support | 2019 |
| Shangri-La Laundry and Ironing Ltd | Other services | 2018 |
| Shard Property Limited | Real estate | 2022 |
| Sharma's Food Limited | Wholesale & retail | 2019 |
| Sharma's House Ltd | Real estate | 2026 |
| Sharone's Secret Source Ltd | Real estate | 2023 |
| Sharpling Limited | Health & social care | 2022 |
| Shaun Greaves Limited | Health & social care | 2011 |
| Shawfield & Sloane Ltd | Administrative & support | 2024 |
| Sheerid Limited | Information & communication | 2020 |
| Sheildog Ltd | Wholesale & retail | 2024 |
| Shekinah Care Limited | Health & social care | 2020 |
| Shelmat Enterprises Limited | Construction | 2000 |
| Shepchar Properties Limited | Real estate | 2019 |
| Shepperton Plant Limited | Wholesale & retail | 1973 |
| Sheque Limited | Wholesale & retail | 2023 |
| Sheringhams Foods Limited | Wholesale & retail | 2022 |
| SHH Yoga Limited | Other services | 2025 |
| Shibah Ltd | Real estate | 2024 |
| Shijie Trading Ltd | Wholesale & retail | 2016 |
| Shine & Glow Cleaning Services Ltd. | Administrative & support | 2015 |
| Shire and Wold Staffing Ltd | Administrative & support | 2019 |
| Shires Appointments Ltd | Professional & scientific | 2025 |
| Shires Property Services Ltd | Construction | 2022 |
| Shires Storage Ltd | Transport & logistics | 2025 |
| Shirestone Advisory Ltd | Professional & scientific | 2023 |
| Shjp Limited | Real estate | 2017 |
| Shortarm Limited | Arts & recreation | 2012 |
| Shreyas Surgeons Limited | Professional & scientific | 2017 |
| SHU WEN Ltd | Wholesale & retail | 2020 |
| SI Beauty Ltd | Wholesale & retail | 2021 |
| Sibuya Property Holdings Limited | Real estate | 2024 |
| Sidalls Bicester Limited | Wholesale & retail | 1982 |
| Sidalls Limited | Construction | 2005 |
| Sifm (Heathrow Airport) Ltd | Manufacturing | 2016 |
| Sifm Ltd | Manufacturing | 2016 |
| Sight Technical Support Ltd | Administrative & support | 2019 |
| Signature Ballroom Ltd | Arts & recreation | 2023 |
| Signature Step Podiatry Ltd | Health & social care | 2023 |
| Silvana Health Ltd | Health & social care | 2023 |
| Silver Falcon Medical Limited | Administrative & support | 2020 |
| Silver Willow Marketing Limited | Professional & scientific | 2012 |
| Silverrail JP UK Limited | Administrative & support | 2013 |
| Silverrail Linkon UK Ltd | Administrative & support | 2014 |
| Silverrail Technologies UK Limited | Wholesale & retail | 2009 |
| Silverspires Ltd | Transport & logistics | 2023 |
| Silverstone Rally School Limited | Arts & recreation | 1989 |
| Silverstone Rally Sport Limited | Arts & recreation | 2008 |
| Simblock Limited | Construction | 2020 |
| Simms & Sons Limited | Manufacturing | 2014 |
| Simple Kitchens (Thame) Limited | Manufacturing | 2007 |
| Simply Synergy Ltd | Other services | 2022 |
| Simpson Amble Associates Ltd | Information & communication | 2024 |
| Sino Link International Limited | Wholesale & retail | 1997 |
| Sino Vision Racing Limited | Arts & recreation | 2009 |
| Sirius Consultancy Services Ltd | Professional & scientific | 2018 |
| SIS Productions Ltd | Professional & scientific | 2024 |
| SIX Aesthetics Ltd | Other services | 2022 |
| Sixeleven Ltd | Real estate | 2019 |
| Siya Healthcare Ltd | Health & social care | 2024 |
| SJ Coachworks Limited | Wholesale & retail | 2018 |
| SJK Management Consultants Limited | Professional & scientific | 2017 |
| SJR Construction Ltd | Construction | 2017 |
| Skillsstation Ltd | Professional & scientific | 2020 |
| Skindose Limited | Other services | 2022 |
| Sky Glow UK Ltd | Wholesale & retail | 2025 |
| Sky Route Travels Worldwide Ltd | Administrative & support | 2026 |
| Skyline Solutions Limited | Professional & scientific | 2016 |
| Slade Estate Services Holdings Limited | Financial services | 2017 |
| Slade Estate Services Ltd | Administrative & support | 2004 |
| Slate Computer Services Ltd | Information & communication | 2008 |
| Slay&Glow Ltd | Wholesale & retail | 2021 |
| Slice Media Agency Ltd | Information & communication | 2022 |
| Slide Master Limited | Professional & scientific | 2023 |
| Slovenian Enterprises Ltd | Professional & scientific | 2020 |
| SLS Electrical Contractors Limited | Construction | 2002 |
| Smag Logistics Ltd | Transport & logistics | 2019 |
| Small Splashes Ltd | Education | 2017 |
| Smart Future Technologies Ltd | Information & communication | 2024 |
| Smartly Candid Solutions Ltd | Information & communication | 2024 |
| Smartship Ltd | Transport & logistics | 2024 |
| Smartz Bookkeeping & Accounts Ltd | Professional & scientific | 2019 |
| Smashed 'N' Loaded Ltd | Hospitality | 2025 |
| Smile Design by DR KAT Limited | Health & social care | 2025 |
| Smilecare Limited | Administrative & support | 1997 |
| SML Real Estate Services Ltd | Professional & scientific | 2026 |
| Smokey Cat Ltd | Real estate | 2021 |
| Smoking Lobster Group Limited | Hospitality | 2024 |
| Smrt Construction Ltd | Construction | 2022 |
| SN Sun D Ltd | Real estate | 2020 |
| Snorydory Limited | Wholesale & retail | 2023 |
| SNS Monistic Ltd | Administrative & support | 2015 |
| Soanesecology Ltd | Professional & scientific | 2024 |
| Soaz Consulting Limited | Professional & scientific | 2017 |
| Socotec Certification United Kingdom Limited | Administrative & support | 1988 |
| Soda.Auto UK Ltd | Information & communication | 2023 |
| Sodbury Fuel Oils Limited | Wholesale & retail | 2016 |
| SOE Projects Ltd | Professional & scientific | 2016 |
| Soeffingrah.Com Limited | Information & communication | 2012 |
| Soft Pauer AI Limited | Information & communication | 2025 |