| Svas Legacy Holdings Ltd | Financial services | 2025 |
| Svema Group Ltd | Wholesale & retail | 2024 |
| SW Floor Screeding Ltd | Construction | 2024 |
| SW Performance Cars Limited | Wholesale & retail | 2021 |
| Swag Giveaways Ltd | Wholesale & retail | 2025 |
| Swag Hats Limited | Manufacturing | 2020 |
| Swagdragon Ltd | Information & communication | 2025 |
| Swallow Close Olney Management Company Limited | Households | 2021 |
| Swallow Hill Properties Ltd | Real estate | 2026 |
| Swan Mcleod Ltd | Real estate | 2025 |
| Swankys (Harpenden) Limited | Hospitality | 2015 |
| Swanston Grange (Luton) Management Limited | Administrative & support | 1986 |
| Swat Management Ltd | Administrative & support | 2024 |
| Sweatscore Limited | Arts & recreation | 2025 |
| Swedish Company Limited | Wholesale & retail | 2019 |
| Sweet Heart Luton Ltd | Hospitality | 2023 |
| Sweet Mirch Masala Limited | Hospitality | 2012 |
| Sweet Mouthful Mixes Ltd | Wholesale & retail | 2020 |
| Sweet Pete's Ltd | Hospitality | 2026 |
| Swetha Foods PVT Ltd | Hospitality | 2025 |
| SWH Automotive Ltd | Wholesale & retail | 2023 |
| Swhs Transport Ltd | Transport & logistics | 2022 |
| Swidish Limited | Wholesale & retail | 2025 |
| Swift Accomodations Services Ltd | Real estate | 2018 |
| Swift Airport Parking Ltd | Other services | 2010 |
| Swift Care Agency Limited | Health & social care | 2020 |
| Swift PCO Hire Ltd | Wholesale & retail | 2025 |
| Swift Pharma Network Limited | Wholesale & retail | 2022 |
| Swift Rental Homes Ltd | Real estate | 2026 |
| Swift Rise Lift Installation Ltd | Construction | 2024 |
| Swift Scaffold Services Limited | Construction | 2002 |
| Swift Solutions Luton Limited | Administrative & support | 2011 |
| Swift Training Academy Ltd | Education | 2024 |
| SWIFT7MEDIA Ltd | Information & communication | 2018 |
| Swiftcartsuppliers Ltd | Wholesale & retail | 2025 |
| Swiftcomm Distribution Limited | Wholesale & retail | 2017 |
| Swiftgo London Ltd | Transport & logistics | 2026 |
| Swifthaven Group Ltd | Wholesale & retail | 2025 |
| Swiftkarwan Ltd | Wholesale & retail | 2025 |
| Swiftline Transport Ltd | Transport & logistics | 2026 |
| Swiftmean Pubs Ltd | Hospitality | 2026 |
| SWIFTSALES1 Ltd | Wholesale & retail | 2025 |
| Swiftsquare Ltd | Wholesale & retail | 2025 |
| Swiftsweeps Chimney Services Ltd | Administrative & support | 2021 |
| Swifttrade Logistics 09 Ltd | Transport & logistics | 2025 |
| Swindon Design Limited | Professional & scientific | 1994 |
| Swisha Care Limited | Administrative & support | 2021 |
| Swiss 10 Ltd | Hospitality | 2026 |
| Switch Employment Ltd | Administrative & support | 2022 |
| Switch Estates Ltd | Real estate | 2024 |
| Switch Line Solutions Ltd | Construction | 2025 |
| Switch Security Ltd | Administrative & support | 2020 |
| Switch Training Ltd | Education | 2022 |
| SWM Scott Ltd | Professional & scientific | 2017 |
| Swren Limited | Other services | 2025 |
| Swwd Ltd | Transport & logistics | 2019 |
| SX Trading Ltd | Wholesale & retail | 2021 |
| Sydenham Cricket & Sports Ground Limited(The) | Real estate | 1925 |
| Syed & Co Estates Ltd | Real estate | 2026 |
| Syed Abbas 786110 Limited | Real estate | 2025 |
| Syed Zone Limited | Wholesale & retail | 2025 |
| Syed's Properties Ltd | Real estate | 2023 |
| SYEDAKAZMI110 Limited | Wholesale & retail | 2025 |
| Syeed ALI Consultancy Ltd | Professional & scientific | 2017 |
| SYK Properties Ltd | Real estate | 2019 |
| SYL Group Investment Limited | Real estate | 2024 |
| SYL Trade International Limited | Wholesale & retail | 2024 |
| Sylhet Bazzar Ltd | Wholesale & retail | 2025 |
| Sylhetbuy.Com Limited | Wholesale & retail | 2025 |
| Sylq Ltd | Wholesale & retail | 2025 |
| Syltex Limited | Wholesale & retail | 2017 |
| Symedia Music Ltd | Information & communication | 2014 |
| SYN Investments Ltd | Real estate | 2020 |
| Synaq Smiles Ltd | Health & social care | 2025 |
| Sync Corner Ltd | Wholesale & retail | 2025 |
| Syncraft Ltd | Construction | 2025 |
| Synergasia London Ltd | Professional & scientific | 2016 |
| Synergy 7 Investment Group Ltd | Real estate | 2015 |
| Synergy Research and Consulting Limited | Professional & scientific | 2015 |
| Synergy Spark Digital Ltd | Wholesale & retail | 2025 |
| Synha Ltd | Information & communication | 2019 |
| Synsta Group CIC | Information & communication | 2025 |
| Syntiumalgo Limited | Information & communication | 2023 |
| SYR Consultancy Limited | Professional & scientific | 2024 |
| Syriana Charcoal Grill Limited | Hospitality | 2023 |
| Sysit-Uk Ltd | Information & communication | 2019 |
| System Performance Tuning Limited | Information & communication | 2024 |
| Systemize Security Ltd | Administrative & support | 2023 |
| Systems 365 Ltd | Information & communication | 2011 |
| Syteldent Limited | Health & social care | 2007 |
| Sytex Investments Ltd | Real estate | 2010 |
| SZ Financial Solutions Ltd | Professional & scientific | 2021 |
| SZ Real Estates Ltd | Professional & scientific | 2022 |
| Szabist Security Limited | Administrative & support | 2025 |
| SZN Supplies Ltd | Wholesale & retail | 2025 |
| SZS Cars Ltd | Transport & logistics | 2023 |
| SZS Group Ltd | Hospitality | 2024 |
| Szymkowska Property Ltd | Real estate | 2024 |
| Szymkowski Limited | Real estate | 2025 |
| Szymon Gsxr Ltd | Wholesale & retail | 2023 |