| Salsabil Ltd. | Manufacturing | 2015 |
| Salt the Earth Publishing Ltd | Information & communication | 2026 |
| SAM Electronics Solution Ltd | Energy | 2014 |
| SAM UK Trader Ltd | Wholesale & retail | 2021 |
| Samax Autotech Company Ltd | Wholesale & retail | 2025 |
| Sammy Moore Coaching Ltd | Arts & recreation | 2021 |
| Samyrise Limited | Information & communication | 2021 |
| Sapphire Projects Limited | Professional & scientific | 2025 |
| Sarah Daramola Limited | Information & communication | 2023 |
| Sarjudas Limited | Financial services | 2025 |
| Sarpanch Recruitment Ltd | Administrative & support | 2022 |
| SAT Bansal Limited | Education | 2015 |
| Satpal Kumar Ltd | Construction | 2023 |
| Satta's Happy Days Childcare Ltd | Health & social care | 2018 |
| Satti Traders Ltd | Wholesale & retail | 2026 |
| Satwant Bisla Construction Limited | Construction | 2025 |
| Savs Barbers (Erith) Limited | Other services | 2018 |
| Sawa MTL Ltd | Hospitality | 2025 |
| SCA Secreterial Services Limited | Professional & scientific | 2019 |
| Scaffpro Access Limited | Construction | 2026 |
| Scarff & Co Renovations Ltd | Construction | 2019 |
| SCL Consulting Ltd | Administrative & support | 2012 |
| Scuffed Alloy Wheel Refurbishment Ltd | Wholesale & retail | 2019 |
| Scvs Enterprises Ltd | Financial services | 2020 |
| SD Solar Limited | Construction | 2025 |
| SE Auto Services Ltd | Wholesale & retail | 2020 |
| Sea Accounting Services Ltd | Real estate | 2021 |
| Seafood Xpress Ltd | Wholesale & retail | 2025 |
| Seamless Services Limited | Construction | 2025 |
| Sec-Tec Limited | Information & communication | 2000 |
| Secunda Alite Consultancy Ltd | Professional & scientific | 2026 |
| Secure GAS Ltd | Construction | 2015 |
| Securetrace Ltd | Transport & logistics | 2025 |
| Security Doors Factory Ltd | Manufacturing | 2019 |
| Sedao Limited | Information & communication | 2004 |
| Selectivelife CIC | Education | 2020 |
| Selkent Recycling Limited | Wholesale & retail | 2013 |
| Selo Ltd | Other services | 2022 |
| Selo Prime Properties Ltd | Real estate | 2024 |
| Semper Gratus Ltd | Professional & scientific | 2025 |
| Send-Iit Limited | Education | 2025 |
| Sensecore AI LAB Limited | Information & communication | 2026 |
| Sequoia Care Ltd | Administrative & support | 2018 |
| Serenity Property Investments Limited | Real estate | 2021 |
| Seropa Limited | Manufacturing | 1999 |
| Service Charge Accounting Limited | Professional & scientific | 2018 |
| Setmaf Logistics Limited | Transport & logistics | 2008 |
| Seyifunmi Ltd | Administrative & support | 2020 |
| SG & Co London Ltd | Professional & scientific | 2020 |
| Sgdm Ltd | Transport & logistics | 2025 |
| Shades Special Foodies Limited | Hospitality | 2026 |
| Shahrukhi Ltd | Information & communication | 2025 |
| Shakti Builder Limited | Construction | 2025 |
| Shakti Developers Ltd | Construction | 2026 |
| Shakunpri Ltd | Wholesale & retail | 2025 |
| Shala&Jmd Ltd | Construction | 2019 |
| Shald Limited | Health & social care | 2016 |
| Shamanic ME Ltd | Manufacturing | 2020 |
| Shanaya Property Ltd | Real estate | 2024 |
| Shape 1 Ltd | Manufacturing | 2022 |
| Shardlink Ltd | Construction | 2013 |
| Shavitz Ltd | Manufacturing | 2025 |
| Shawk Properties Limited | Real estate | 2021 |
| SHE2SQUARE Limited | Health & social care | 2020 |
| Sheg'Z Cars Ltd | Wholesale & retail | 2025 |
| Shekinah Training & Consultancy Limited | Education | 2013 |
| Shelf Figures Limited | Wholesale & retail | 2025 |
| Shenkco & Son's Limited | Health & social care | 2023 |
| Shenstone Developments (UK) Ltd | Construction | 2012 |
| Shepherds Haven Ltd | Real estate | 2024 |
| Shermansbury Limited | Extraterritorial | 2015 |
| Shiloh International Recruitment Ltd | Administrative & support | 2023 |
| Shiman Ltd | Wholesale & retail | 2015 |
| Shirnicol Limited | Professional & scientific | 2020 |
| SHJ Builders Ltd | Construction | 2025 |
| SHOP2ME Limited | Administrative & support | 2018 |
| Showmeg International Limited | Professional & scientific | 2023 |
| Shows Heating Services Ltd | Construction | 2017 |
| Shurety Services Ltd | Construction | 2017 |
| SI Management Ltd | Hospitality | 2025 |
| Sicol-Global Services Ltd | Wholesale & retail | 2018 |
| Sidela Mills Ltd | Wholesale & retail | 2018 |
| Siftworks Ltd | Wholesale & retail | 2025 |
| Signature Kisses Ltd | Wholesale & retail | 2017 |
| Sigora Enterprises Ltd | Real estate | 2020 |
| Siid Properties Ltd | Real estate | 2021 |
| SIJ Holdings Ltd | Financial services | 2018 |
| Sika Healthcare Services Ltd | Health & social care | 2022 |
| Sikander Construction Ltd | Administrative & support | 2017 |
| Silicon Tower Consultancy Services Limited | Construction | 2023 |
| Silver Frith Limited | Financial services | 2014 |
| Silver House Investors Ltd | Professional & scientific | 2024 |
| Silver House UK Ltd | Real estate | 2009 |
| Simba Convenience Store Ltd | Wholesale & retail | 2019 |
| Simian Leisure Limited | Hospitality | 2006 |
| Simply Sensory Dementia Support CIC | Health & social care | 2025 |
| Simply Sensory Ltd | Health & social care | 2023 |
| Simpsonmek Autos Ltd | Wholesale & retail | 2026 |
| Simrat PAL Singh Ltd | Construction | 2023 |
| Sims Luxurious Hair Limited | Other services | 2025 |