| Shoppix Limited | Wholesale & retail | 2024 |
| Shopspark Ltd | Wholesale & retail | 2025 |
| Shoptrica Limited | Wholesale & retail | 2025 |
| Shopvero Ltd | Wholesale & retail | 2026 |
| Shopwyze Limited | Wholesale & retail | 2025 |
| Short Term Vehicles Ltd | Professional & scientific | 2026 |
| Shorts (Lifts) Limited | Extraterritorial | 1996 |
| Shorts Environmental Limited | Extraterritorial | 1997 |
| Shorts Industries Limited | Wholesale & retail | 1982 |
| Showstoppers Fashion Ltd | Wholesale & retail | 2025 |
| Showtime Hospitality Limited | Administrative & support | 2024 |
| SHP Derby Limited | Wholesale & retail | 2013 |
| Shree PVT Ltd | Wholesale & retail | 2025 |
| Shrewds Business Consultancy Ltd | Professional & scientific | 2013 |
| SHS Marketing Limited | Wholesale & retail | 2021 |
| Shudh Limited | Professional & scientific | 2018 |
| Shumi Empire Limited | Real estate | 2009 |
| Shunbee Healthcare CIC | Administrative & support | 2025 |
| Shuraim Limited | Wholesale & retail | 2026 |
| Shyu Ltd | Manufacturing | 2022 |
| Shzn Ltd | Wholesale & retail | 2025 |
| Si-Med Cosmo Ltd | Public administration | 2022 |
| SIA Direct Ltd | Administrative & support | 2026 |
| SIA Pharma Consulting Limited | Professional & scientific | 2014 |
| SIA Property's Ltd | Real estate | 2021 |
| Sia.Clozet Ltd | Wholesale & retail | 2025 |
| Siabapharma Ltd | Wholesale & retail | 2023 |
| Sial Properties Ltd | Real estate | 2026 |
| Sialkot Traders Limited | Wholesale & retail | 2021 |
| Siam (Yorkshire) Ltd | Real estate | 2026 |
| Siam Sensations Ltd | Hospitality | 2025 |
| Siaz Solutions Ltd | Transport & logistics | 2026 |
| Sibaa Ltd | Wholesale & retail | 2022 |
| Sibley Properties Limited | Real estate | 2011 |
| Sibongile Healthcare PVT Limited | Health & social care | 2015 |
| Sicuteco Ltd | Real estate | 2025 |
| SID Consultants Limited | Professional & scientific | 2021 |
| Sidats Group Ltd | Hospitality | 2022 |
| Siddique Ltd | Health & social care | 2025 |
| Siddiqui Group Ltd | Administrative & support | 2018 |
| Siddy’S Electronics Ltd | Wholesale & retail | 2025 |
| Sidecurtain Services Limited | Manufacturing | 2005 |
| Sidetarget Limited | Arts & recreation | 1988 |
| Sideways LAB Ltd | Information & communication | 2026 |
| Sidhom Ltd | Health & social care | 2026 |
| SIDI77 Property's Ltd | Real estate | 2026 |
| Sidings Self Storage Ltd | Real estate | 2026 |
| Sidra Tours & Travel Ltd | Administrative & support | 2026 |
| Sidrah Selection Limited | Wholesale & retail | 2020 |
| Sidrra Holdings Ltd | Wholesale & retail | 2025 |
| Sids Movements Ltd | Wholesale & retail | 2020 |
| Sidsag Ltd | Hospitality | 2026 |
| Sief Global Solutions Limited | Other services | 2019 |
| Sierra Logistics Ltd | Transport & logistics | 2026 |
| SIG Developments Ltd | Real estate | 2024 |
| Sightix Security Systems Limited | Administrative & support | 2026 |
| Sigley Plumbing Services Limited | Construction | 2026 |
| Sigma IT Consultants Limited | Information & communication | 2018 |
| Sigma Leisure Management Ltd | Administrative & support | 2006 |
| Sigmapro Limited | Professional & scientific | 2003 |
| Sign & Graphic Installations Ltd | Construction | 2019 |
| Sign Concepts Ltd | Manufacturing | 2014 |
| Signal Flight Ltd | Professional & scientific | 2026 |
| Signal Trace Ltd | Manufacturing | 2026 |
| Signature Agents UK Ltd | Arts & recreation | 2026 |
| Signature Bargains Ltd | Wholesale & retail | 2021 |
| Signature Coatings Limited | Construction | 2022 |
| Signature Detailing Ltd | Administrative & support | 2024 |
| Signature Estates & Lettings Limited | Real estate | 2014 |
| Signature Executive Travel Ltd | Transport & logistics | 2026 |
| Signature Mall Bradford Limited | Real estate | 2024 |
| Signature Management Services Ltd | Real estate | 2026 |
| Signature Marketing Limited | Information & communication | 2025 |
| Signature Properties Bradford Ltd | Real estate | 2025 |
| Signgalaxy Ltd | Manufacturing | 2022 |
| Signiture Homes Ltd | Real estate | 2026 |
| Signology UK Ltd | Manufacturing | 2026 |
| Signone Ltd | Professional & scientific | 2012 |
| Signs by Design 2020 Ltd | Manufacturing | 2017 |
| Siha Supplements Limited | Wholesale & retail | 2026 |
| Sijfx Solutions Ltd | Information & communication | 2024 |
| SIK Optical Ltd | Health & social care | 2021 |
| Sikalius Limited | Wholesale & retail | 2025 |
| Sikdipz Limited | Wholesale & retail | 2025 |
| Sikri Limited | Construction | 2026 |
| SIL Holdings Limited | Financial services | 2001 |
| Silent Dreams Textiles Ltd | Manufacturing | 2026 |
| Silent Events Ltd | Arts & recreation | 2013 |
| Silently Hustle Hard Ltd | Other services | 2020 |
| Silicon Valley Accessories Ltd | Manufacturing | 2024 |
| Silk Insurance Brokers Ltd | Financial services | 2018 |
| Silk Route Traders Ltd | Wholesale & retail | 2026 |
| Silkstone Cars Ltd | Wholesale & retail | 2017 |
| Silktouch Direct Ltd | Wholesale & retail | 2022 |
| Silsila Brands Limited | Wholesale & retail | 2023 |
| Silver (UK) Limited | Administrative & support | 2004 |
| Silver Dragon Trading Limited | Wholesale & retail | 2023 |
| Silver Duck Ltd | Wholesale & retail | 2010 |
| Silver Facilities Solutions Limited | Administrative & support | 2025 |
| Silver Fountain Limited | Real estate | 2007 |