| Sebastian Alexander Ltd | Construction | 2022 |
| Sebastian Talent Services Ltd | Administrative & support | 2021 |
| Secad Ltd | Hospitality | 2025 |
| Second Light Limited | Information & communication | 2008 |
| Secta Finance Limited | Financial services | 2018 |
| Secta Group Limited | Professional & scientific | 2021 |
| Secta Research Limited | Professional & scientific | 2025 |
| Section A-A Limited | Financial services | 2022 |
| Secudo Ltd | Real estate | 2020 |
| Secure Source Ltd | Administrative & support | 2011 |
| Secure Store Holding Ltd | Extraterritorial | 2023 |
| Securezero Ltd | Other services | 2021 |
| Securious Limited | Information & communication | 2007 |
| Security Alliance Limited | Information & communication | 2007 |
| Security and Management Ltd | Administrative & support | 2022 |
| Security Training South West Limited | Administrative & support | 2011 |
| Sedecrem Holdings Ltd | Administrative & support | 2020 |
| Sedge Mead Works Ltd | Financial services | 2026 |
| Sedgemoor Tree Services Limited | Agriculture & fishing | 2012 |
| SEE Data Ltd | Information & communication | 2010 |
| Seed Talent Limited | Extraterritorial | 2022 |
| Seed-Exe-Change CIC | Administrative & support | 2021 |
| Seeing the Light Limited | Administrative & support | 2017 |
| Sefooco Limited | Transport & logistics | 2025 |
| Seize the Stay Limited | Real estate | 2024 |
| Select Car Repair SW Limited | Wholesale & retail | 2023 |
| Select Cars Countrywide Limited | Wholesale & retail | 2023 |
| Select Cars SW Limited | Wholesale & retail | 2018 |
| Select Statistical Services Ltd | Information & communication | 2011 |
| Select SW Property 1 Limited | Financial services | 2020 |
| Select SW Property 2 Limited | Wholesale & retail | 2023 |
| Select Technology Sales and Distribution (UK) Limited | Wholesale & retail | 2009 |
| Selecta-One UK Ltd | Wholesale & retail | 2003 |
| Selene Psychology Limited | Health & social care | 2025 |
| Self Build Plots Limited | Real estate | 2022 |
| SELSDON74 Limited | Real estate | 2025 |
| Seltaa Ltd | Information & communication | 2022 |
| SEM Investments Limited | Other services | 2021 |
| Sema SPV 1 Limited | Real estate | 2021 |
| SEN Tutoring South West Ltd | Education | 2025 |
| Sena Sogutlu Limited | Arts & recreation | 2026 |
| Sena UK Ltd | Hospitality | 2026 |
| Senapsis Group Ltd | Financial services | 2025 |
| Senapsis Ltd | Professional & scientific | 2019 |
| Senate Consultants Limited | Professional & scientific | 2023 |
| Senescence Health Limited | Health & social care | 2025 |
| Senior Designs Ltd | Information & communication | 2020 |
| Senisca Ltd | Professional & scientific | 2020 |
| Sensian Research Limited | Information & communication | 2013 |
| Sensoryme Ltd | Information & communication | 2025 |
| Sentari Intelligence Ltd | Information & communication | 2026 |
| September Homes Limited | Professional & scientific | 2016 |
| Sequenti Investments Ltd | Real estate | 2017 |
| Sequenti Ltd | Financial services | 2017 |
| Serene Developments Limited | Real estate | 2017 |
| Serenity Children's Services Ltd | Health & social care | 2022 |
| Serenity Scalp Health Ltd | Other services | 2026 |
| Servara Ltd | Administrative & support | 2026 |
| Serviced Haus Limited | Real estate | 2024 |
| Services for Tourism Limited | Other services | 2008 |
| Servicetech South West Partnerships | | 2006 |
| Servicetech Southwest | | 2004 |
| Servo Engineering Ltd | Professional & scientific | 2000 |
| Sestaret Limited | Education | 2015 |
| SET Forty Holdings Ltd | Real estate | 2022 |
| SET Price Ltd | Construction | 2020 |
| SET2RECRUIT Ltd | Administrative & support | 2009 |
| Seta Limited | Real estate | 2025 |
| Seth Lakeman Limited | Information & communication | 2005 |
| Sevad Limited | Wholesale & retail | 2005 |
| Seven and Eight Belle Court Management Ltd | Extraterritorial | 2015 |
| Seven Star I Limited | Wholesale & retail | 2008 |
| Sevens Barbers Ltd | Other services | 2025 |
| Seventh Sense Healing Limited | Arts & recreation | 2017 |
| Seventy Four Hundred Technical Marketing Limited | Professional & scientific | 2021 |
| Severn Servicing Garages Limited | Wholesale & retail | 2017 |
| Seyyo Investment Limited | Professional & scientific | 2025 |
| SF Aviation Services Ltd | Information & communication | 2024 |
| SG Automotive Repairs Limited | Wholesale & retail | 2023 |
| SG Education Consultancy Ltd | Education | 2025 |
| SG Personal Management Ltd | Real estate | 2015 |
| SGC Merchandise Ltd | Wholesale & retail | 2025 |
| SGT Holdings Ltd | Real estate | 2021 |
| SH Creative Property Solutions Limited | Real estate | 2024 |
| SH Realisations 2025 Ltd | Wholesale & retail | 2010 |
| Shaan Express Ltd | Hospitality | 2023 |
| Shaan Realty Limited | Real estate | 2021 |
| Shades of Tuning Ltd | Manufacturing | 2023 |
| Shahzain & Shahwaiz Ltd | Wholesale & retail | 2025 |
| Shakina Enterprises Limited | Professional & scientific | 2007 |
| Shakspeare Services Limited | Professional & scientific | 1999 |
| Shallcott Limited | Health & social care | 1997 |
| Shamian Limited | Wholesale & retail | 2016 |
| Shanan Leigh Ltd | Construction | 2022 |
| Shane Berry Engineering Limited | Professional & scientific | 2015 |
| Shanghai FB 2025 Limited | Hospitality | 2025 |
| Shaolin Investments Ltd | Real estate | 2020 |
| Shape and Letter Limited | Professional & scientific | 2015 |
| Sharif Bespoke Tailoring Ltd | Wholesale & retail | 2019 |
| Sharif Tailoring & Alterations Limited | Wholesale & retail | 2020 |