| Scio Healthcare Limited | Health & social care | 2003 |
| SCM GAS Ltd | Construction | 2022 |
| Scooby Harvey Ltd | Professional & scientific | 2025 |
| Scorpio Business Solutions Limited | Administrative & support | 2010 |
| Scott Stewart Autos Ltd. | Wholesale & retail | 1994 |
| SCP Asset Finance Ltd | Financial services | 2020 |
| SCP Surgery Ltd | Health & social care | 2024 |
| SCR Plumbing & Heating Ltd | Construction | 2015 |
| SCR Renovations Ltd | Manufacturing | 2024 |
| Scratch Built Productions Limited | Arts & recreation | 2006 |
| Sculpture Castings Ltd | Manufacturing | 2009 |
| SCW Organisation Limited | Professional & scientific | 2010 |
| SD1912 Ltd | Construction | 2020 |
| Sdan Properties Limited | Real estate | 2024 |
| SDC Project Consulting Limited | Professional & scientific | 2025 |
| SDO Wealth Management Ltd | Financial services | 2017 |
| SDR Strength Ltd | Arts & recreation | 2016 |
| SDS Smith's Damp Solutions Ltd | Construction | 2025 |
| SDX Consulting Services Limited | Professional & scientific | 2024 |
| Sea Ride Ltd | Transport & logistics | 2024 |
| Sea Spray (Combe Martin) Limited | Hospitality | 2022 |
| Seabird Properties Limited | Real estate | 2020 |
| Seabung Limited | Manufacturing | 2013 |
| Seahorse Investments Ltd | Information & communication | 2020 |
| Seama Limited | Wholesale & retail | 2022 |
| Sean Hicks Flooring Limited | Construction | 2019 |
| Sean White Renovations Ltd | Construction | 2025 |
| Seaside Apartments (Combe Martin) Limited | Real estate | 2025 |
| Seaside Studio Limited | Hospitality | 2022 |
| Sebastian D Trans Ltd | Transport & logistics | 2025 |
| Sebastian's Action Trust | Other services | 2012 |
| Second Phase Construction Ltd | Manufacturing | 2005 |
| Secur-Fix Limited | Wholesale & retail | 2013 |
| Secure IT Recycling Ltd | Information & communication | 2019 |
| Securerite Ltd | Administrative & support | 2025 |
| Securifix Security Systems Limited | Administrative & support | 1997 |
| Securiframe Limited | Manufacturing | 2004 |
| Security 4 Peace Ltd | Professional & scientific | 2024 |
| Security Hashtag Ltd | Information & communication | 2019 |
| Sedum Growers Limited | Agriculture & fishing | 2017 |
| SEE Further Algorithmic Limited | Information & communication | 2026 |
| SEE Property Solutions Ltd | Real estate | 2026 |
| SEE Quality Solutions Ltd | Professional & scientific | 2024 |
| SEE Scents Ltd | Wholesale & retail | 2020 |
| Seedscale Ltd | Professional & scientific | 2024 |
| Seesai Thai Massage & Spa Ltd | Health & social care | 2024 |
| Sefte Consulting Ltd | Information & communication | 2012 |
| Segue - Home of Quality Ltd | Real estate | 2021 |
| Selcourt Planned Maintenance Limited | Administrative & support | 2007 |
| Select Health Care General Limited | Financial services | 2019 |
| Select Primecare Limited | Health & social care | 2013 |
| Selector Solutions Ltd | Administrative & support | 2014 |
| Sellion Ltd | Wholesale & retail | 2025 |
| Sematron Holdings Limited | Professional & scientific | 2013 |
| Sematron Limited | Information & communication | 2013 |
| Sematron UK Limited | Manufacturing | 2019 |
| Senapt Communications Limited | Information & communication | 2024 |
| Senapt Group Limited | Financial services | 2022 |
| Senapt Research Limited | Information & communication | 2025 |
| Senapt Technologies Limited | Information & communication | 2025 |
| Senetas Europe Limited | Information & communication | 2001 |
| Senise Limited | Information & communication | 2015 |
| Senko Advanced Components (Euro) Limited | Manufacturing | 1994 |
| Sennaco Limited | Administrative & support | 2018 |
| Sennovate Ltd | Information & communication | 2017 |
| Sequel Consulting Limited | Professional & scientific | 2019 |
| Serenity Cater Enterprise Ltd | Wholesale & retail | 2011 |
| Serenity Landscapes and Ponds Limited | Professional & scientific | 2026 |
| Seril Engineering Limited | Professional & scientific | 2017 |
| Serve Plus Limited | Information & communication | 2013 |
| Servershopping.Com Ltd | Information & communication | 2009 |
| Service for a Reason CIC | Education | 2022 |
| Service Holdings Ltd | Administrative & support | 2024 |
| Service TEN Ltd | Administrative & support | 2018 |
| Servio Holdings Limited | Construction | 2019 |
| Servio Limited | Construction | 1995 |
| Servio Technology Limited | Wholesale & retail | 2008 |
| Sesame-Uk Limited | Hospitality | 2018 |
| SET Marketing Services Limited | Professional & scientific | 1997 |
| Setao Electrical Limited | Construction | 2024 |
| Setie Ltd | Information & communication | 2024 |
| Sevace Limited | Professional & scientific | 2024 |
| Sevenstarcare Limited | Health & social care | 2017 |
| Sevyn K9 Ltd | Other services | 2026 |
| Sexton Welding and Fabrication Ltd | Manufacturing | 2015 |
| SF Autocare Ltd | Wholesale & retail | 2025 |
| SF Fibre Ltd | Construction | 2022 |
| Sfaith & Sons Ltd | Manufacturing | 2026 |
| Sfintech Ltd | Information & communication | 2022 |
| SFK Solutions Limited | Information & communication | 2023 |
| SG Finserv Ltd | Administrative & support | 2023 |
| SGB Healthcare Limited | Health & social care | 2021 |
| SGK Signature Holdings UK Limited | Financial services | 2025 |
| SGN Transport Ltd. | Transport & logistics | 2016 |
| SGV Group Limited | Financial services | 2023 |
| SGV Property Solutions Limited | Real estate | 2023 |
| SGW Plant Hire Ltd | Construction | 2012 |
| SH Enforcement Limited | Professional & scientific | 2007 |
| Shachris Limited | Real estate | 2004 |
| Shackleton Blackmore & Taylor Limited | Real estate | 1994 |