| Sincere Homes (Solihull) Ltd | Real estate | 2022 |
| Sincere Homes Limited | Real estate | 2017 |
| Singh Medics Limited | Health & social care | 2015 |
| Singhtech Solutions Limited | Information & communication | 2013 |
| Singwell CIC | Other services | 2024 |
| Sinha Investments Ltd | Health & social care | 2020 |
| Sinha Medical Ltd | Health & social care | 2025 |
| Sino Koolmill Limited | Professional & scientific | 2009 |
| Siobhan Mcdonald Consultancy Limited | Professional & scientific | 2024 |
| Sipholdings Ltd | Health & social care | 2026 |
| Sire Construction Ltd | Construction | 2020 |
| Sirina Projects (Syston) Limited | Construction | 2023 |
| Sirina Projects Ltd | Construction | 2017 |
| Sirona Design Limited | Professional & scientific | 2015 |
| Sirrahclean Ltd | Administrative & support | 2021 |
| Sirtek (Birmingham) Limited | Hospitality | 2011 |
| Sirtek (Digbeth) Limited | Hospitality | 2011 |
| Sirtek (Dudley) Limited | Hospitality | 2013 |
| SIS CAB Services Ltd | Transport & logistics | 2025 |
| Sitaram International Limited | Health & social care | 2020 |
| Site Reliability Services Limited | Information & communication | 2019 |
| SIV Consultancy Limited | Professional & scientific | 2018 |
| SIV Property Limited | Real estate | 2022 |
| Siva TEC Limited | Wholesale & retail | 1997 |
| SIX at Seven Limited | Households | 2012 |
| SIX Cheers Limited | Hospitality | 2016 |
| SIX Hairdressing Limited | Administrative & support | 2017 |
| SIX One Zero Ltd | Hospitality | 2017 |
| Sixplus Ltd | Real estate | 2023 |
| Sixty SIX Leadership Coaching Ltd | Administrative & support | 2025 |
| Sizzle Innovation CIC | Administrative & support | 2022 |
| SJ Interpreters Ltd | Professional & scientific | 2024 |
| SJ Optical Ltd | Health & social care | 2017 |
| SJ Scaffolding Services Limited | Construction | 2021 |
| SJB Avionics Limited | Manufacturing | 2019 |
| SJB People Limited | Administrative & support | 2024 |
| SJE Group Limited | Administrative & support | 2020 |
| SJH Affiliate Limited | Professional & scientific | 2024 |
| SJL Services & Plant Ltd | Construction | 2018 |
| SJM and RWM Ltd | Real estate | 2019 |
| SJP Planning Limited | Professional & scientific | 2010 |
| Sjpc Properties Ltd | Real estate | 2025 |
| SJS Electrical & Property Renovations Ltd | Construction | 2023 |
| SJT K9 Services Ltd | Other services | 2018 |
| SJV Accounting Services Ltd | Professional & scientific | 2016 |
| SK Accounting & Analytics Ltd | Professional & scientific | 2019 |
| SK Consultancy 26 Ltd | Professional & scientific | 2026 |
| SK28 Ltd | Real estate | 2025 |
| Skan Group Holdings Limited | Financial services | 2016 |
| Skantag Limited | Administrative & support | 2021 |
| Skdv Properties Ltd | Real estate | 2026 |
| Skehill Brickwork Contractors Ltd | Construction | 2010 |
| Skelly Medical Services Limited | Health & social care | 2014 |
| SKG Alno Limited | Wholesale & retail | 2019 |
| SKG Group Limited | Wholesale & retail | 1999 |
| SKG Projects Limited | Wholesale & retail | 2019 |
| SKG Property Investments Limited | Real estate | 2023 |
| Skin Consulting (UK) Ltd | Health & social care | 2010 |
| Skin on YOU Ltd | Wholesale & retail | 2022 |
| Skin World UK Ltd | Wholesale & retail | 2020 |
| Skinner Home Developments Limited | Construction | 2026 |
| Skinner Homes Limited | Real estate | 2024 |
| Skinner Property Developments Limited | Construction | 2023 |
| SKM Prestige Cars Ltd | Wholesale & retail | 2024 |
| Skog Property Limited | Real estate | 2025 |
| Skratch Indoor Golf Ltd | Arts & recreation | 2024 |
| Skrep Developments Ltd | Construction | 2015 |
| Skrep Gloucester Ltd | Construction | 2015 |
| SKS Laser Processing Holdings Limited | Financial services | 2022 |
| SKS Laser Processing Limited | Manufacturing | 2013 |
| Skwedel Ltd | Professional & scientific | 2020 |
| Sky Bar Nottingham Ltd | Arts & recreation | 2026 |
| Sky Blue Staffing Ltd | Administrative & support | 2021 |
| Sky Captures Ltd | Professional & scientific | 2021 |
| Sky Elevators Ltd | Manufacturing | 2012 |
| Sky High Property Management Ltd | Real estate | 2023 |
| Sky Infotech Ltd | Information & communication | 2019 |
| Sky Rise Properties Limited | Construction | 2006 |
| Skyace UK Ltd | Construction | 2025 |
| Skybuffer Ltd | Construction | 2012 |
| Skyhigh Financials Ltd | Professional & scientific | 2014 |
| Skyish Ltd | Real estate | 2020 |
| Skyline Lifting International Ltd | Construction | 2024 |
| Skyline Scaffolding Group Limited | Construction | 2026 |
| Skymate Limited | Professional & scientific | 2002 |
| Skyroute Aviation (UK) Ltd | Wholesale & retail | 2008 |
| Skywall Limited | Other services | 2017 |
| Skyway (Birmingham) Limited | Wholesale & retail | 2003 |
| Skywise Solutions Ltd | Professional & scientific | 2015 |
| SL Accountants Limited | Professional & scientific | 2006 |
| SL M&E Site Management Services Ltd | Construction | 2026 |
| SL Models Ltd | Professional & scientific | 2022 |
| SL UK Investment Company Limited | Real estate | 2017 |
| Slaney Homes Ltd | Extraterritorial | 2015 |
| Slater Bros Properties Ltd | Construction | 2019 |
| SLB Construction Services Ltd | Construction | 2023 |
| SLB System Solutions Ltd | Information & communication | 2011 |
| Sleadrin Surveying Ltd | Professional & scientific | 2019 |
| Sleep Store Stoke Ltd | Wholesale & retail | 2021 |
| Slice of Chai Ltd | Hospitality | 2025 |