| Smart Recruitment Ltd | Real estate | 2023 |
| Smart Refurb Ltd | Construction | 2010 |
| Smart Sense Ltd | Hospitality | 2019 |
| Smart Services Enterprise Ltd | Other services | 2021 |
| Smart Sourcing International Ltd | Wholesale & retail | 2026 |
| Smart Stock Ltd | Wholesale & retail | 2017 |
| Smartbuy Enterprises Limited | Wholesale & retail | 2025 |
| SMARTCARE1 Ltd | Real estate | 2025 |
| Smartdeal Express Limited | Wholesale & retail | 2025 |
| Smartfoods Products Limited | Manufacturing | 2012 |
| SMI Marketing Limited | Information & communication | 2020 |
| Smigo Consultants Ltd | Professional & scientific | 2021 |
| Smis & Co (UK) Ltd | Manufacturing | 2011 |
| Smith & Schuller Ltd | Education | 2019 |
| Smith Terrace Holdings Ltd | Real estate | 2026 |
| Smith Wires Limited | Extraterritorial | 1975 |
| Smokey Pro Limited | Manufacturing | 2021 |
| Smsm Therapy Ltd | Other services | 2017 |
| SNA Drylining Ltd | Construction | 2018 |
| Snap Selection Ltd | Wholesale & retail | 2024 |
| Snappy Savings Limited | Wholesale & retail | 2026 |
| SND Estates Limited | Real estate | 2024 |
| Snddo Business Services Limited | Administrative & support | 2016 |
| Sneak Peek Technologies Limited | Information & communication | 2023 |
| Sniffari Ltd | Other services | 2023 |
| SNS International Ltd | Wholesale & retail | 2009 |
| Sofia Building Contractor Ltd | Construction | 2020 |
| Soft Spot Bakery Ltd | Hospitality | 2026 |
| Softspun Ltd | Manufacturing | 2019 |
| Sokol Landscaping Limited | Administrative & support | 2019 |
| Solid Brick Construction Ltd | Manufacturing | 2025 |
| Solomon Properties & Investment Ltd | Real estate | 2023 |
| Somali Community CIC | Health & social care | 2020 |
| Somboat Ltd | Health & social care | 2016 |
| Sonic Transport Limited | Transport & logistics | 2026 |
| Sophrosyne Solutions Ltd | Professional & scientific | 2017 |
| Sorubaranee Ltd | Real estate | 2019 |
| Souq Ltd | Wholesale & retail | 2024 |
| Sourced GA Ltd | Real estate | 2022 |
| South Anglian Services Ltd | Construction | 2026 |
| South East Property Ltd | Real estate | 2005 |
| South West Trades Ltd | Administrative & support | 2020 |
| Southbank Rope Access Ltd | Construction | 2015 |
| Southpark Properties (UK) Limited | Construction | 2014 |
| Southpark Residential Home Limited | Health & social care | 1995 |
| Southwest Mobile Auto Care Ltd | Wholesale & retail | 2019 |
| Southwestraders Ltd | Wholesale & retail | 2020 |
| Southwestruns Limited | Wholesale & retail | 2024 |
| Sovereign Carpets Flooring Specialist Ltd | Construction | 2025 |
| Sowabuilder Limited | Construction | 2020 |
| Sozoit Limited | Information & communication | 2025 |
| SP Group Contractors Ltd | Construction | 2023 |
| Spaced in Limited | Manufacturing | 2001 |
| Spade Developments Limited | Construction | 2017 |
| Spanner & Works Ltd | Real estate | 2024 |
| Spark and Bloom Limited | Information & communication | 2023 |
| Sparkle Cleaning Co. (London) Limited | Administrative & support | 1991 |
| Sparks Express UK Limited | Wholesale & retail | 2026 |
| Spartik Ltd | Wholesale & retail | 2024 |
| Special Garden Services Limited | Administrative & support | 2013 |
| Speciality Chemicals International Limited | Financial services | 2016 |
| Spectrum Communications (UK) Ltd | Professional & scientific | 2007 |
| Spetsen Consulting Ltd | Professional & scientific | 2023 |
| Sphere Services Ltd | Transport & logistics | 2019 |
| Spider Clothing US Ltd | Wholesale & retail | 2025 |
| Spill the Beans Ltd | Education | 2024 |
| Spin MII Limited | Arts & recreation | 2023 |
| Spit Spot Cleaning Ltd | Administrative & support | 2017 |
| Sporting Assist Limited | Education | 2023 |
| Sports Injury FIX Limited | Health & social care | 2016 |
| Sports Wellness & Recreation CIC | Education | 2025 |
| Spqr Pizza Ltd | Wholesale & retail | 2020 |
| Spro Investments Limited | Real estate | 2025 |
| SPS I Ltd | Financial services | 2012 |
| SPS Timber Windows Limited | Manufacturing | 1998 |
| SQ Systems Limited | Extraterritorial | 2004 |
| Squires Steel Stockholders Limited | Extraterritorial | 1982 |
| SR Engineers Group Limited | Professional & scientific | 2020 |
| SR Photography Ltd | Professional & scientific | 2024 |
| SR1 Ltd | Real estate | 2007 |
| Srct Ltd | Other services | 2023 |
| Srfk Properties Ltd | Real estate | 2023 |
| SRI and Shanthy Ltd | Real estate | 2021 |
| SRI Murugan Stores Ltd | Wholesale & retail | 2020 |
| SRI Navadhurgai Amman Temple Limited | Other services | 2018 |
| Srihara Ltd | Information & communication | 2020 |
| Sriram Catering Ltd | Hospitality | 2026 |
| SRK Lettings and Management Ltd | Households | 2025 |
| SRS & Partners Holding Ltd | Real estate | 2024 |
| SRS & Partners Ltd | Real estate | 2024 |
| SRS Project Management Ltd | Administrative & support | 2025 |
| SRZ Financials UK Ltd | Financial services | 2026 |
| SS Josan Constructions Limited | Construction | 2015 |
| SS Takeaway Food Limited | Hospitality | 2026 |
| SS Windows Limited | Manufacturing | 2017 |
| Ssbd Solutions Limited | Education | 2024 |
| SSG Executive Transport Ltd | Transport & logistics | 2023 |
| Sshr Capital Limited | Real estate | 2025 |
| SSK (PVT) Ltd | Real estate | 2025 |
| St.Antony's Ltd | Health & social care | 2012 |