| Sewvaden Ltd | Administrative & support | 2024 |
| Seymour Development Group Limited | Real estate | 2025 |
| Seymour Legal Advisory LLP | | 2020 |
| SF Beattie Ltd | Administrative & support | 2022 |
| SFN Estates Ltd | Real estate | 2020 |
| SGM Music Group Limited | Arts & recreation | 2015 |
| Shadecauf Ltd | Administrative & support | 2024 |
| Shadeware Ltd | Transport & logistics | 2019 |
| Shaks Convenience Ltd | Wholesale & retail | 2023 |
| Shams (U.K.) Ltd. | Manufacturing | 1990 |
| Shane Smith Limited | Construction | 2024 |
| Shanuka News & Offlicence Ltd | Wholesale & retail | 2016 |
| Sharing Purpose Ltd | Professional & scientific | 2024 |
| Sharp CUT Barbers 1 Ltd | Other services | 2024 |
| Sharratt Property Developments Ltd | Professional & scientific | 2016 |
| Sharratt Property Holdings Ltd | Real estate | 2015 |
| Shawtrack Light Commercial Bodies Limited | Manufacturing | 2024 |
| Shawtrack Services Limited | Other services | 2023 |
| Shea TM Ltd | Construction | 2025 |
| Shear Perfection Limited | Administrative & support | 2008 |
| Sheet Metal Services (Midlands) Limited | Manufacturing | 2007 |
| Sheidenzy Ltd | Wholesale & retail | 2023 |
| Shekinah Healthcare Services Ltd | Health & social care | 2024 |
| Shelbourne Developments Limited | Construction | 1991 |
| Shell the Heating Engineer Ltd | Construction | 2025 |
| Sheng HUI Kitchen Limited | Hospitality | 2021 |
| Shield Products Limited | Information & communication | 2000 |
| Shiftfuse Ltd | Administrative & support | 2019 |
| Shiftvice Ltd | Transport & logistics | 2019 |
| Shilam Limited | Wholesale & retail | 2024 |
| Shimzebar Ltd | Administrative & support | 2024 |
| Shinwari Express Limited | Manufacturing | 2020 |
| Shire Stoves & Flues Installations Limited | Wholesale & retail | 2025 |
| Shire Tipis Limited | Administrative & support | 2017 |
| Shire Views Ltd | Administrative & support | 2022 |
| Shivcheer Ltd | Administrative & support | 2024 |
| SHK Animal Therapy Ltd | Professional & scientific | 2023 |
| Shofi & Co Ltd | Wholesale & retail | 2025 |
| Shop Anytime Ltd | Wholesale & retail | 2025 |
| Shopbots Ltd | Wholesale & retail | 2019 |
| Shorter Brothers Ltd | Construction | 2025 |
| Show Solutions Limited | Professional & scientific | 1999 |
| Shropshire Adventures Ltd | Arts & recreation | 2024 |
| Shugbam Ltd | Wholesale & retail | 2024 |
| Siandesk Ltd | Administrative & support | 2024 |
| Sigma Engineering Solutions Ltd | Manufacturing | 2005 |
| Signal Holdings Limited | Financial services | 2024 |
| Signal Rigging Ltd | Information & communication | 2021 |
| Signal Traffic Management Ltd | Transport & logistics | 2012 |
| Signature Stationery Ltd | Wholesale & retail | 2025 |
| Silcock Network Solutions Ltd | Construction | 2019 |
| Silecriz Ltd | Administrative & support | 2024 |
| Sillydimple Ltd | Administrative & support | 2019 |
| Silterser Ltd | Transport & logistics | 2018 |
| Silver Machine Professional Services Limited | Information & communication | 2020 |
| Silvertail Books Limited | Information & communication | 2012 |
| Simic Limited | Real estate | 2005 |
| Simma Consulting Ltd | Information & communication | 2021 |
| Simms Consultancy Limited | Professional & scientific | 2012 |
| Simon Brooks Limited | Financial services | 2018 |
| Simon Brooks Properties Limited | Real estate | 2025 |
| Simon Wormington Limited | Other services | 2009 |
| Simply Car Mats Limited | Manufacturing | 2020 |
| Simply Church | Health & social care | 1998 |
| Simply Limitless | Health & social care | 2010 |
| Singh and Singh Enterprises Ltd | Real estate | 2024 |
| Sion Hill Fish Bar Limited | Hospitality | 2020 |
| Site Solutions (Worcs) Limited | Professional & scientific | 2017 |
| Site Stencil UK Ltd | Wholesale & retail | 2024 |
| Sitegain Residents Management Limited | Households | 1986 |
| Sizewell Ltd | Administrative & support | 2022 |
| SJA Holdings Limited | Real estate | 2007 |
| SJB Contracting Services Limited | Construction | 2025 |
| SJH Surveying Services Ltd | Households | 2017 |
| SJW Automotive Limited | Wholesale & retail | 2026 |
| SK Mcloughlin Ltd | Administrative & support | 2021 |
| SKB Construction and Maintenance Limited | Construction | 2013 |
| Skiathium Ltd | Administrative & support | 2024 |
| Skin Plans Limited | Other services | 2023 |
| SKP Commerce Ltd | Real estate | 2022 |
| Skura Investments Limited | Real estate | 2024 |
| Sladd Barn Livery Stables Limited | Agriculture & fishing | 2008 |
| Slamburgers Ltd | Transport & logistics | 2019 |
| Slayyourlook Limited | Other services | 2024 |
| Slim Without Surgery Limited | Health & social care | 2020 |
| Slingsby Securities Ltd | Financial services | 2022 |
| Slipdart Ltd | Transport & logistics | 2019 |
| SM Independent Consultant Ltd | Information & communication | 2019 |
| Smart Epos Limited | Information & communication | 2014 |
| Smart Epos NI Limited | Information & communication | 2025 |
| Smart GAS Heating & Plumbing Services Ltd | Construction | 2019 |
| Smart Motorway Services Limited | Professional & scientific | 2015 |
| Smart NRG Limited | Wholesale & retail | 2015 |
| Smartek CNC Ltd | Wholesale & retail | 2024 |
| Smartwire Electrical Services Limited | Construction | 2012 |
| Smash My Catering Ltd | Hospitality | 2024 |
| Smashmypatty Ltd | Hospitality | 2023 |
| SME Investors Group Ltd | Administrative & support | 2026 |
| Smokey Joes BBQ Ltd | Hospitality | 2025 |
| SN Howe Ltd | Administrative & support | 2022 |