| Saint Sister Faustyna Polish Language School in Slough C.I.C. | Information & communication | 2021 |
| Saint Solutions Limited | Information & communication | 2022 |
| Saire Technologies Limited | Information & communication | 2024 |
| Saisri Properties Ltd | Real estate | 2022 |
| Saitech Consultants Limited | Information & communication | 2010 |
| Saiyam Properties Limited | Real estate | 2026 |
| Sajid Electrical Services Ltd | Construction | 2024 |
| SAK London Limited | Hospitality | 2020 |
| Sakina Construction Ltd | Construction | 2017 |
| Sakjg Limited | Professional & scientific | 2015 |
| Sakn Ltd | Wholesale & retail | 2023 |
| Sakuba Properties Limited | Real estate | 2023 |
| Sakuma Impex Ltd | Wholesale & retail | 2023 |
| SAL Holistic Services Ltd | Households | 2014 |
| Salaam Homes Limited | Real estate | 2025 |
| Salaam Journeys Ltd | Administrative & support | 2026 |
| Salamidrive Ltd | Transport & logistics | 2021 |
| Sales Plus Ltd | Real estate | 2015 |
| Sales Secure Ltd | Wholesale & retail | 2021 |
| Sales Space Ltd | Education | 2025 |
| Sales Support Group Limited | Administrative & support | 1966 |
| Salia Courier Services Ltd | Transport & logistics | 2024 |
| Salicious Foods Ltd | Hospitality | 2018 |
| Salient Film Company Ltd | Information & communication | 2025 |
| Salisbury RD Estates Ltd | Real estate | 2018 |
| Saliv Ltd | Financial services | 2024 |
| Salk Local Ltd | Wholesale & retail | 2023 |
| Salsha Holding Limited | Professional & scientific | 2024 |
| Salt Hill Digital CIC | Education | 2025 |
| Salt Hill VR Ltd | Information & communication | 2023 |
| Salty Consulting Ltd | Information & communication | 2022 |
| Salwa Group Limited | Wholesale & retail | 2023 |
| Salwa Takeaway Ltd | Manufacturing | 2020 |
| SAM Accountancy & Consultancy Ltd | Professional & scientific | 2025 |
| SAM Benipal Ltd | Transport & logistics | 2024 |
| SAM Catering Services Ltd | Hospitality | 2016 |
| SAM Coaching Limited | Administrative & support | 2019 |
| SAM Martin Consulting Limited | Administrative & support | 2025 |
| SAM Trading Company Limited | Wholesale & retail | 2010 |
| SAM Waste Recycling Ltd | Water & waste | 2017 |
| Samad Overseas Service (UK) Ltd | Administrative & support | 2011 |
| Samahi Ltd | Construction | 2024 |
| Samangan Consulting Ltd | Professional & scientific | 2014 |
| Samangan Limited | Wholesale & retail | 2019 |
| Samani Care Ltd | Health & social care | 2014 |
| Samansh Ltd | Information & communication | 2008 |
| Samarj UK Limited | Health & social care | 2014 |
| Samarjit Enterprise Limited | Transport & logistics | 2019 |
| Samary Care Home Limited | Health & social care | 2025 |
| Sambhi Construction Limited | Construction | 2024 |
| Samco Holdings Ltd | Financial services | 2020 |
| Samco Ventures Limited | Real estate | 2022 |
| Sameer Traders Ltd | Wholesale & retail | 2025 |
| Sameevun Consulting Limited | Information & communication | 2015 |
| Samin Travel Limited | Transport & logistics | 2000 |
| Samm Services Limited | Professional & scientific | 2023 |
| Samm Store Ltd | Wholesale & retail | 2025 |
| Sammad Ltd | Wholesale & retail | 2025 |
| Sampson Best Appliance Recyle Ltd | Wholesale & retail | 2025 |
| Samreen Logistics Ltd | Transport & logistics | 2026 |
| Samriddhi Consulting Ltd | Information & communication | 2018 |
| Samriddhi Enterprises Ltd | Real estate | 2018 |
| Samroh IT Limited | Information & communication | 2016 |
| Sams Fashion UK Limited | Wholesale & retail | 2024 |
| Sams Skip Hire LT Ltd | Water & waste | 2026 |
| Sams Skip Hire Ltd | Water & waste | 2022 |
| Samsa Ltd | Hospitality | 2025 |
| Samsbikes Ltd | Wholesale & retail | 2024 |
| Samsonia Limited | Information & communication | 2014 |
| Samuel Adjei Limited | Information & communication | 2024 |
| Samuel's & Sons Ltd | Construction | 2024 |
| Samuelsey Limited | Other services | 2020 |
| SAN & Co Accountants Ltd | Professional & scientific | 2004 |
| SAN & Co Ltd | Professional & scientific | 2014 |
| SAN Abodes Ltd | Real estate | 2020 |
| SAN Car Sales Ltd | Wholesale & retail | 2025 |
| SAN Consultancy Limited | Information & communication | 2007 |
| SAN Corporation Limited | Real estate | 2019 |
| Sana Fashion Limited | Wholesale & retail | 2024 |
| Sanaa Bakes Ltd | Wholesale & retail | 2025 |
| Sanbros Developments Limited | Real estate | 2015 |
| Sanbros Ltd | Wholesale & retail | 2010 |
| Sanbros Management Limited | Hospitality | 2014 |
| Sanchari House of Dance CIC | Arts & recreation | 2026 |
| Sanco Integrated Services Limited | Information & communication | 2010 |
| Sandgate Systems Limited | Information & communication | 2010 |
| Sandhawalia & Sons Ltd | Transport & logistics | 2015 |
| Sandher & SON Ltd | Transport & logistics | 2017 |
| Sandher Properties Ltd | Real estate | 2019 |
| Sandhu & Sandhu Transport Ltd | Transport & logistics | 2022 |
| Sandhu Affiliate Marketing Ltd | Professional & scientific | 2024 |
| Sandhu Brothers Limited | Transport & logistics | 2020 |
| Sandhu Building Solutions Ltd | Construction | 2025 |
| Sandhu Building Works Ltd | Construction | 2026 |
| Sandhu CONSTRUCTION1 Ltd | Construction | 2023 |
| Sandhu Enterprises (UK) Limited | Wholesale & retail | 2007 |
| Sandhu Fish & Chips Ltd | Hospitality | 2026 |
| Sandhu Healthcare Limited | Wholesale & retail | 2025 |
| Sandhu Property Estates Limited | Real estate | 2025 |
| Sandhu Psychiatric Services Limited | Health & social care | 2025 |