| SJK Electrical Limited | Construction | 2004 |
| SJR Repairs Ltd | Manufacturing | 2025 |
| SJS (2) Limited | Real estate | 2005 |
| SJS (4) Limited | Real estate | 1988 |
| SJS (Derby) Limited | Real estate | 2005 |
| SJS Property Holdings Ltd | Real estate | 2024 |
| SJT Development Projects Ltd | Real estate | 2021 |
| SK Auto Solutions Ltd | Wholesale & retail | 2024 |
| SK Delivery Limited | Transport & logistics | 2023 |
| SK Design (Yorkshire) Ltd | Professional & scientific | 2010 |
| SK Healthcare Services Ltd | Administrative & support | 2025 |
| SK Initium Ltd | Transport & logistics | 2024 |
| SK Optics Limited | Health & social care | 2017 |
| SK Pingan Ltd | Hospitality | 2020 |
| SKA Properties Yorkshire Ltd | Real estate | 2023 |
| Skanderbeg AG | Professional & scientific | 2018 |
| Skaur Services Ltd | Professional & scientific | 2026 |
| SKE Building Solutions Limited | Construction | 2020 |
| Skhara Ltd | Real estate | 2026 |
| Skidmore Construction Ltd | Construction | 2023 |
| Skillsrx Ltd | Wholesale & retail | 2026 |
| Skinner Holdings Limited | Financial services | 2026 |
| SKN LAB Yorkshire Ltd | Education | 2024 |
| Skydorado GmbH | Real estate | 2016 |
| Skyes Lettings Ltd | Hospitality | 2024 |
| Skyhold Properties Ltd | Real estate | 2022 |
| Skyhooks Engineering Ltd | Professional & scientific | 2021 |
| Skylake Management LLP | | 2020 |
| Skyline Motion Limited | Wholesale & retail | 2024 |
| Skytechsport Club | Manufacturing | 2018 |
| SL Cyber Ltd | Administrative & support | 2024 |
| SL Hydraulics Ltd | Manufacturing | 2021 |
| SL24 Ltd. | Professional & scientific | 2004 |
| Sladurski Accommodation Ltd | Transport & logistics | 2022 |
| Slanjayvah Danza | Arts & recreation | 2007 |
| Slava Tiling Limited | Construction | 2019 |
| Slcc Limited | Other services | 2021 |
| Slcontrive Limited | Wholesale & retail | 2024 |
| Sleek Signet Limited | Education | 2026 |
| Sleep Nest Ltd | Wholesale & retail | 2020 |
| Sleep Perfect Ltd | Manufacturing | 2025 |
| Sleepeeze Ltd | Manufacturing | 2024 |
| Sleepy Knight Ltd | Wholesale & retail | 2019 |
| Sleepy Rooster Media Limited | Information & communication | 2024 |
| Sleeve Dreams Ltd | Wholesale & retail | 2016 |
| SLH Medical Services Limited | Health & social care | 2025 |
| Slice of Gratitude Ltd | Professional & scientific | 2018 |
| Sliced and Iced Ltd | Extraterritorial | 2023 |
| Slim Fadey Ltd | Other services | 2024 |
| Slimline Windows Limited | Wholesale & retail | 2002 |
| Slink Northern Ltd | Administrative & support | 2013 |
| SLJ Consultancy Limited | Professional & scientific | 2022 |
| SLT Care Ltd | Health & social care | 2008 |
| SLT Solutions & Consultancy Limited | Information & communication | 2019 |
| Sluggy Beats Ltd | Information & communication | 2026 |
| SM Partnership Ltd | Real estate | 2020 |
| SM Removal Services Ltd | Transport & logistics | 2026 |
| Smar-Technology Limited | Manufacturing | 2001 |
| Smart Barbers Wakefield Limited | Other services | 2023 |
| Smart Crosby International Holdings Ltd | Financial services | 2025 |
| Smart Crosby International Ltd. | Professional & scientific | 1993 |
| Smart Electrical Wakefield Ltd | Construction | 2025 |
| Smart Frameworks Limited | Administrative & support | 2009 |
| Smart Guard Security (UK) Limited | Administrative & support | 2026 |
| Smart Service Tools Ltd. | Professional & scientific | 2021 |
| Smart Supply Ltd | Wholesale & retail | 2016 |
| Smart Synergy Ltd | Construction | 2007 |
| Smart Tech Support Ltd | Information & communication | 2022 |
| Smart Van Lease Hub Ltd | Administrative & support | 2025 |
| Smartarm Building Contractors Ltd | Construction | 2025 |
| Smartbuild Property Experts Limited | Construction | 2022 |
| Smartfix Plumbing and Heating Ltd | Construction | 2025 |
| Smartpaint Yorkshire Ltd | Wholesale & retail | 2024 |
| Smarts Plumbing UK Limited | Construction | 2020 |
| Smartsec Information Security Ltd | Information & communication | 2019 |
| SMB Design & Artwork Limited | Professional & scientific | 2007 |
| SMB Engineering Services Ltd | Professional & scientific | 2022 |
| SMD Building Services Limited | Construction | 1997 |
| Smeeden Foreman Ltd | Professional & scientific | 2008 |
| SMH (Wakefield) Limited | Professional & scientific | 2016 |
| SMH Lettings Limited | Real estate | 2020 |
| SMH Real Estate Ltd | Real estate | 2024 |
| SMH175 Ltd | Financial services | 2025 |
| Smic Graphic Ltd | Administrative & support | 2016 |
| Smile Customer Experience Limited | Professional & scientific | 2014 |
| Smiley Dayz Limited | Education | 2009 |
| Smirthwaite Limited | Manufacturing | 2008 |
| Smith & Ellis Electrical Ltd | Construction | 2024 |
| Smith Varo Property Limited | Construction | 2020 |
| Smiths Forensic Accounting Limited | Professional & scientific | 2024 |
| SML Waky Services Limited | Real estate | 2025 |
| Smokehouse Real BBQ Limited | Hospitality | 2014 |
| Smooktech Limited | Wholesale & retail | 2018 |
| Smyth Construction Management Limited | Construction | 2011 |
| SN 3 Ventures Limited | Wholesale & retail | 2026 |
| Sn&Sn Funeral Services Limited | Other services | 2026 |
| Snackman Ltd | Wholesale & retail | 2023 |
| Snaveuk Ltd | Information & communication | 2019 |
| SNF (UK) Limited | Wholesale & retail | 1986 |
| SNF International Limited | Administrative & support | 2018 |