| Swan Studio Clothing Ltd | Wholesale & retail | 2025 |
| Swanport Limited | Transport & logistics | 1984 |
| Swantel Ltd | Information & communication | 2019 |
| Swaran Singh Khalsa Properties Ltd | Real estate | 2022 |
| Sway Evolve Limited | Manufacturing | 2019 |
| Swayne-B Ltd | Professional & scientific | 2023 |
| Swaz Holdings Limited | Hospitality | 2022 |
| Sweet Barkingside London Ltd | Hospitality | 2021 |
| Sweet Family Affair Limited | Wholesale & retail | 2015 |
| Sweet Limited | Extraterritorial | 2015 |
| Sweet Rose Cakery Limited | Hospitality | 2016 |
| Sweet UK Limited | Extraterritorial | 2003 |
| SWEET1NE Cuisine Ltd | Hospitality | 2021 |
| Sweetsler ELM Park Ltd | Wholesale & retail | 2024 |
| Sweetsler Ltd | Hospitality | 2024 |
| Sweetzler Ilford Limited | Hospitality | 2024 |
| Swift EPC Ltd | Construction | 2025 |
| Swift Home Services Ltd | Transport & logistics | 2026 |
| Swift Investments Services Ltd | Professional & scientific | 2022 |
| Swift Messengers Gospel Centre | Other services | 2004 |
| Swift Property Repairs Ltd | Construction | 2025 |
| Swift PVT Services Ltd | Information & communication | 2025 |
| Swift Selection Trading Limited | Wholesale & retail | 2025 |
| Swift Services TN Ltd | Water & waste | 2020 |
| Swift Ship Central Ltd | Wholesale & retail | 2026 |
| Swift UK Transport Services Limited | Transport & logistics | 2014 |
| Swift Wears International Ltd | Wholesale & retail | 2024 |
| Swiftbell Limited | Health & social care | 2013 |
| Swiftbook Accountancy Ltd | Professional & scientific | 2022 |
| Swiftbuy Ltd | Wholesale & retail | 2025 |
| Swiftbuy Mart Ltd | Wholesale & retail | 2025 |
| Swiftgo Transport Ltd | Transport & logistics | 2026 |
| Swiftimise Ltd | Wholesale & retail | 2023 |
| Swiftline Investments Limited | Real estate | 2019 |
| Swiftmart Global Ltd | Wholesale & retail | 2025 |
| Swiftmart Trading Ltd | Wholesale & retail | 2025 |
| Swiftrail Scaffolding Limited | Other services | 1997 |
| Swiftserve Maintenance Ltd | Construction | 2026 |
| Swiftsync AI Ltd | Information & communication | 2025 |
| Swiftt Remit Limited | Financial services | 2025 |
| Swifty AI Limited | Information & communication | 2024 |
| Swirldrop Treats Ltd | Hospitality | 2021 |
| Swiss Real Estate Ltd | Real estate | 2023 |
| Swiss Shark Ltd | Hospitality | 2026 |
| Switch Housing Limited | Real estate | 2022 |
| Switch IT UP Autos Ltd | Wholesale & retail | 2023 |
| Swiths Ltd | Real estate | 2022 |
| Swonda Ltd | Information & communication | 2014 |
| Sword Facilities Management Limited | Administrative & support | 2020 |
| Swraj Nanda Construction Ltd | Construction | 2024 |
| SWV Consultant Ltd | Professional & scientific | 2021 |
| SWW Co (UK) Ltd | Construction | 2013 |
| SWY Holdings Ltd | Financial services | 2026 |
| Swyft Clean Ltd | Administrative & support | 2026 |
| Swyft Moves Ltd | Transport & logistics | 2026 |
| SX Fireworks Ltd | Wholesale & retail | 2026 |
| Sxifulvip Limited | Wholesale & retail | 2024 |
| SY Management & Consultancy Ltd | Professional & scientific | 2014 |
| SY Pharma Ltd | Wholesale & retail | 2026 |
| Sycamore Aesthetics Ltd | Health & social care | 2024 |
| SYD Property Group Ltd | Real estate | 2020 |
| Sydenham MOT Ltd | Wholesale & retail | 2025 |
| Sydney Estate Agent Ltd | Real estate | 2020 |
| Sydney IFA Limited | Financial services | 2020 |
| Sydney Properties Limited | Real estate | 2013 |
| Syed Arif Limited | Professional & scientific | 2002 |
| Syed Atelier Ltd | Information & communication | 2022 |
| Syed Global Trading Ltd | Wholesale & retail | 2026 |
| Syed Multi Store Limited | Wholesale & retail | 2018 |
| Syed Solicitors Ltd | Professional & scientific | 2025 |
| Syed Vintage Group Ltd | Wholesale & retail | 2021 |
| Syed Vintage Ltd | Wholesale & retail | 2018 |
| Syed-Chowdhury & Associates Ltd | Professional & scientific | 2026 |
| Syeda Shameea Catering Services Ltd | Hospitality | 2026 |
| Syedco Ltd | Information & communication | 2025 |
| Syedjee Luggage UK Limited | Wholesale & retail | 2021 |
| Syedora Ltd | Wholesale & retail | 2026 |
| Syedsys Limited | Information & communication | 2025 |
| SYG Associates Limited | Wholesale & retail | 2026 |
| Sygnus Construction Ltd | Construction | 2020 |
| Sygnus Services Ltd | Wholesale & retail | 2025 |
| SYH Consulting Limited | Financial services | 2017 |
| Sykes Education LLP | | 2025 |
| Sykes Sports Coaching Limited | Education | 2019 |
| Sylhet Online Service Ltd | Professional & scientific | 2021 |
| Sylvies Property Solutions Ltd | Construction | 2025 |
| SYM 2 Catering Limited | Hospitality | 2025 |
| SYM Consultancy Ltd | Professional & scientific | 2022 |
| Symart Consulting Limited | Information & communication | 2012 |
| Syme Properties Limited | Real estate | 2018 |
| Symmetry Inc Ltd | Wholesale & retail | 2017 |
| Symphony Solutions Ltd | Information & communication | 2015 |
| Symphony Testing Solutions Limited | Information & communication | 2012 |
| Symthson Rose Property Ltd | Real estate | 2015 |
| Synaptech Solutions Limited | Information & communication | 2026 |
| Synatech Limited | Manufacturing | 2024 |
| Synauctor Ltd | Information & communication | 2025 |
| Syncla Ltd | Information & communication | 2026 |
| Syncrx Ltd | Information & communication | 2025 |
| Synctech Solutions Ltd | Information & communication | 2023 |