| Shidhi Ltd | Health & social care | 2025 |
| Shieldworks Construction Limited | Construction | 2025 |
| Shine Beds Limited | Manufacturing | 2017 |
| Shinyar Barbers Limited | Other services | 2019 |
| Shirtmaster Limited | Professional & scientific | 1973 |
| SHJ Recycling Ltd | Water & waste | 2023 |
| Shko Cuts Limited | Other services | 2023 |
| SHL Solutions Limited | Wholesale & retail | 2013 |
| Shoe & Glove Company Ltd | Wholesale & retail | 2025 |
| Shopeaze Convenience Store Ltd | Wholesale & retail | 2026 |
| Shopyyship Ltd | Wholesale & retail | 2025 |
| Shore Equipment Limited | Professional & scientific | 2025 |
| Short Hills Ltd | Wholesale & retail | 2014 |
| Shosh (Crofton) LLP | | 2021 |
| Shospot Ltd | Information & communication | 2020 |
| Shotum Developments Ltd | Construction | 2014 |
| Showland Living Ltd | Construction | 2026 |
| Shred Lifestyle Limited | Arts & recreation | 2022 |
| Shredx Wakefield Ltd | Arts & recreation | 2025 |
| Shredx-Transformations Ltd | Arts & recreation | 2025 |
| Shree Ganesh Local Ltd | Wholesale & retail | 2025 |
| Shth Limited | Administrative & support | 2022 |
| Shubana Healthcare Services Ltd | Health & social care | 2022 |
| Shutter Count Media Ltd | Professional & scientific | 2025 |
| SHW Vehicle Solutions Limited | Wholesale & retail | 2026 |
| Sibex Properties Limited | Extraterritorial | 2005 |
| Siciliano Pizza House Limited | Hospitality | 2022 |
| Siedler Ltd. | Construction | 2016 |
| Siginature Limited | Administrative & support | 2012 |
| Sigma Foam Products Ltd | Manufacturing | 2022 |
| Sigma Plant Hire Ltd | Administrative & support | 2021 |
| Sigma Property Investments (Yorkshire) Ltd | Real estate | 2021 |
| Sigma Travel Limited | Transport & logistics | 2016 |
| Sigma Utilities Ltd | Professional & scientific | 2017 |
| Sigmacrest Communications Limited | Information & communication | 2006 |
| Sign Structures Limited | Manufacturing | 2000 |
| Signature Couriers (International) Limited | Transport & logistics | 2017 |
| Signature Grandview Estates Ltd | Households | 2025 |
| Sigston Property Ltd | Real estate | 2021 |
| Silexa Ltd | Professional & scientific | 2014 |
| Silkwood Homes Limited | Real estate | 2019 |
| Silkwood Treatment Rooms Ltd | Other services | 2020 |
| Silly Goose Club Ltd | Arts & recreation | 2025 |
| Silo-Tech Limited | Manufacturing | 2022 |
| Silver Lining Group Limited Partnership | | 2008 |
| Silver Ridge Creative Limited | Professional & scientific | 2026 |
| Silver Scissors Wakefield Limited | Other services | 2025 |
| Silver Spice Ltd | Hospitality | 2017 |
| Silverback Plumbing and Heating Ltd | Construction | 2020 |
| Silverium Ltd. | Wholesale & retail | 2005 |
| Silvermere Properties Ltd | Real estate | 2020 |
| Silvertini Group Ltd | Hospitality | 2025 |
| Silviac Limited | Construction | 2003 |
| Simam Digital Limited | Information & communication | 2022 |
| Simex Aerospace Limited | Information & communication | 2016 |
| Simkus Transport Ltd | Transport & logistics | 2024 |
| Simon Paton Services Ltd | Transport & logistics | 2011 |
| Simon Services (Wakefield) Limited | Wholesale & retail | 2014 |
| Simon T Barlow Limited | Information & communication | 2015 |
| Simple Joinery Ltd | Construction | 2026 |
| Simple Nile Ltd | Hospitality | 2020 |
| Simpler Mini Market Ltd | Wholesale & retail | 2024 |
| Simplify ER Limited | Administrative & support | 2013 |
| Simply Registrations (Holdings) Limited | Professional & scientific | 2019 |
| Simply Registrations Ltd | Wholesale & retail | 2005 |
| Simson Estate Agents Ltd | Real estate | 2024 |
| Simson Properties (UK) Ltd. | Real estate | 1999 |
| Simul Digital Ltd | Information & communication | 2021 |
| Single Muslim Limited | Information & communication | 2007 |
| Sinlo Ltd | Extraterritorial | 2022 |
| Sintax Innovations Ltd | Information & communication | 2026 |
| Sintering Consultancy Limited | Professional & scientific | 2021 |
| SIP. Hospitality Ltd | Hospitality | 2024 |
| Sipas Transport Ltd | Transport & logistics | 2025 |
| Sirbu Sorin Transport Limited | Transport & logistics | 2016 |
| Sirdar Group Limited | Professional & scientific | 2015 |
| Sirdar Holdings Limited | Wholesale & retail | 2007 |
| Sirra Group Ltd | Administrative & support | 2007 |
| Sisi J Enterprises Ltd | Wholesale & retail | 2026 |
| Sisqo Transport Services Ltd | Transport & logistics | 2019 |
| Siss Partners Limited | Wholesale & retail | 2021 |
| Sisters Garden Services (Leeds) Ltd | Administrative & support | 2025 |
| Site Installation Services (Yorkshire) Limited | Professional & scientific | 2019 |
| Site Service Solutions Ltd | Construction | 2016 |
| Sitorian Limited | Wholesale & retail | 2008 |
| Siunta Ltd | Transport & logistics | 2025 |
| Sivam Infotech Limited | Information & communication | 2025 |
| Siwaju UK Limited | Information & communication | 2017 |
| SIX Acres Luxury Dog Boarding Ltd | Other services | 2024 |
| SIX Sigma Capital Limited | Financial services | 2019 |
| SIX-800 Limited | Professional & scientific | 2004 |
| Sixninetwelve Limited | Professional & scientific | 2014 |
| Sizzlers Takeaway Ltd | Hospitality | 2024 |
| SJ Roberts Tiling Limited | Construction | 2019 |
| SJA Printing Limited | Professional & scientific | 2019 |
| SJB Houses Limited | Construction | 2014 |
| SJB Music Group Ltd | Information & communication | 2011 |
| Sjea Ltd | Real estate | 2025 |
| SJG Freehold Limited | Real estate | 2008 |
| SJH Driveways Limited | Construction | 2017 |