| Seabrook Investments Two Ltd | Real estate | 2024 |
| Seafox Limited | Extraterritorial | 2011 |
| Sean Robert Hogan Ltd | Arts & recreation | 2018 |
| Seance Limited | Information & communication | 2015 |
| Seaton Management Ltd | Professional & scientific | 2020 |
| Second Person Limited | Information & communication | 2013 |
| SECURE4SURE Limited | Administrative & support | 2021 |
| Seetwo Developments Limited | Construction | 2018 |
| Sekkei Studio Ltd | Professional & scientific | 2020 |
| Select Show Company Ltd | Arts & recreation | 2022 |
| Self Containered Limited | Transport & logistics | 2004 |
| Self-Lay Electric Utilities Ltd | Construction | 2022 |
| Self-Lay Services Ltd | Construction | 2019 |
| Self-Lay Training Ltd | Construction | 2021 |
| Sell My Left Hand Drive Car Ltd | Wholesale & retail | 2025 |
| Selman RE Limited | Real estate | 2025 |
| Selworthy Business Services Limited | Professional & scientific | 2008 |
| Senate Films Limited | Information & communication | 2025 |
| Senate Publishing Limited | Administrative & support | 2002 |
| Senet Magazine Limited | Information & communication | 2019 |
| Senvinter Limited | Professional & scientific | 2026 |
| Serendib Solutions Ltd | Wholesale & retail | 2012 |
| Serenity Housing Ltd | Real estate | 2020 |
| Seriously Tacky Limited | Wholesale & retail | 2013 |
| Serve Asset Management Ltd | Financial services | 2025 |
| Serve Holdings Ltd | Financial services | 2025 |
| Sevenne Business Group Ltd | Information & communication | 2021 |
| SFA Properties Limited | Extraterritorial | 2004 |
| SG GGC Ltd | Professional & scientific | 2012 |
| SGI Installers Ltd | Construction | 2012 |
| Shadbolt Construction Limited | Construction | 2013 |
| Shakir Consultancy Ltd | Health & social care | 2022 |
| Shalloak Limited | Real estate | 2023 |
| Shalomi Ltd | Other services | 2013 |
| Shan Pizza Limited | Hospitality | 2022 |
| Shannon Court Residents Association Limited | Other services | 1961 |
| Sheba Cleaning Limited | Administrative & support | 2008 |
| Sheehan Solutions Ltd | Real estate | 2025 |
| Sheer Style Limited | Other services | 2019 |
| Sherwood House Flats Management Company Limited | Real estate | 2016 |
| Sherwood Investments Limited | Real estate | 1959 |
| Shine Brighter Consulting Ltd | Professional & scientific | 2016 |
| Ship Super Limited | Information & communication | 2011 |
| Shishagear.Com Ltd | Wholesale & retail | 2020 |
| Shiv Shakti Holdings Ltd | Wholesale & retail | 2024 |
| Shokk & AWE Limited | Manufacturing | 2026 |
| Shriyan Technologies Limited | Information & communication | 2010 |
| Shronics Ltd | Information & communication | 2019 |
| Sicily Exclusive Ltd | Administrative & support | 2009 |
| Signet Hill Management Company Ltd | Real estate | 2017 |
| Siluvai Media Ltd | Professional & scientific | 2022 |
| Silver Kite Limited | Wholesale & retail | 1998 |
| Silverbrook Care Leases Ltd | Real estate | 2026 |
| Silverbrook Care Ltd | Health & social care | 2025 |
| Silverdene Solutions Ltd | Professional & scientific | 2023 |
| Silverwood Investments Limited | Financial services | 1961 |
| Simplex Human Resources Ltd | Administrative & support | 2016 |
| Simply Legal Team Limited | Professional & scientific | 2019 |
| Simply Sorted Storage Limited | Real estate | 2026 |
| Simply the Best Web Design Limited | Information & communication | 2007 |
| Simpson Street Consultants Limited | Professional & scientific | 2016 |
| Singularis Media Limited | Administrative & support | 2021 |
| Sinople Baron DE Nizerolles Ltd. | Information & communication | 2011 |
| Sips & Nibbles LLP | | 2025 |
| SIS Homes (UK) Ltd | Education | 2016 |
| Sisi and LOU Limited | Wholesale & retail | 2020 |
| Site Engineering Surveys Limited | Construction | 1990 |
| Siveen London Ltd | Real estate | 2018 |
| Sixty Sixty Two Onslow Limited | Households | 1996 |
| SJE Consultants Ltd | Professional & scientific | 2025 |
| SJK Boiler Solutions Ltd | Construction | 2017 |
| SJR Tech Services Limited | Information & communication | 2024 |
| SJW Homes Limited | Real estate | 2019 |
| Skada Limited | Professional & scientific | 2010 |
| Sketch Insight & Consulting Limited | Professional & scientific | 2017 |
| Skill Line Limited | | 1987 |
| Skin and Wellness Clinic Ltd | Health & social care | 2023 |
| Sksz Limited | Wholesale & retail | 2025 |
| Skta Engineering Ltd | Construction | 2019 |
| Sky Blue Exports Ltd | Administrative & support | 2021 |
| Sky Guard Patrols Limited | Administrative & support | 2026 |
| Sky Guide Limited | Education | 2022 |
| Sky Panda Travels and Tours Limited | Administrative & support | 2025 |
| Slioch Access Limited | Professional & scientific | 2021 |
| Slph Consulting Ltd | Professional & scientific | 2022 |
| Smart Corporate Outsource Solutions Limited | Information & communication | 2012 |
| Smash N FRY Limited | Hospitality | 2026 |
| SMR Neurodevelopment Ltd | Real estate | 2023 |
| SN Cloud Solutions Ltd | Information & communication | 2023 |
| SN Sound & Vision Limited | Information & communication | 2015 |
| Snowfocus Limited | Administrative & support | 1996 |
| Socius 24 Limited | Information & communication | 2013 |
| Socius 24 Trustee Limited | Extraterritorial | 2023 |
| Socket World Ltd | Wholesale & retail | 2011 |
| Solrforce Ltd | Construction | 2023 |
| Solveig Ferlet Ltd | Professional & scientific | 2019 |
| Solway Ventures Limited | Extraterritorial | 2014 |
| Somi UK Limited | Other services | 2009 |
| Sommers Apartments (Ilfracombe) Limited | Households | 2022 |
| SON & Oak Homes Ltd | Real estate | 2025 |