| Shirley Shelley Contract Cleaners Limited | Administrative & support | 2010 |
| Shirley Shelley Industrial Cleaners Limited | Administrative & support | 2010 |
| Shivoham Enterprise Limited | Wholesale & retail | 2014 |
| Shockwave Media Ltd | Administrative & support | 2017 |
| Shogun Metal Welding & Fabrication Ltd | Manufacturing | 2016 |
| Shoot-Edit.Co.Uk Limited | Information & communication | 2006 |
| Shop East Ltd | Wholesale & retail | 2019 |
| Shop Foods Ltd | Wholesale & retail | 2025 |
| Shopeehub Limited | Wholesale & retail | 2023 |
| Shopily Ltd | Wholesale & retail | 2025 |
| Shopistan Ltd | Wholesale & retail | 2025 |
| Shopper's Sanctuary Limited | Wholesale & retail | 2023 |
| Shoppeverse Ltd | Wholesale & retail | 2022 |
| Shopxpress Ltd | Wholesale & retail | 2024 |
| Shore 2 Ship Limited | Administrative & support | 2013 |
| Shoreline Shipping Ltd | Transport & logistics | 2020 |
| Short Factory Racing Limited | Arts & recreation | 2021 |
| Shorts Property People Limited | Real estate | 2019 |
| Shoshevi Ltd | Transport & logistics | 2012 |
| Shotley Holdings Limited | Administrative & support | 1992 |
| Shotley Lodge Management Company Limited | Households | 2018 |
| Shotley Stores Limited | Real estate | 2002 |
| Showbus Digital Limited | Administrative & support | 2006 |
| Showcase Consulting Limited | Professional & scientific | 2025 |
| Showroom Plumbing & Heating Ltd | Construction | 2019 |
| Showyourcolours Fashion Ltd | Wholesale & retail | 2022 |
| SHR Cleaning Limited | Administrative & support | 2025 |
| Shred With ED Ltd | Health & social care | 2025 |
| Shredding Machinery Solutions Limited | Manufacturing | 2020 |
| Shrubland Holdings Limited | Extraterritorial | 2024 |
| Shybairn Theatre Ltd | Arts & recreation | 2022 |
| SI JE Puis Ltd | Administrative & support | 2017 |
| Sicher Technik Limited | Professional & scientific | 1994 |
| Siddle Construction Services Ltd | Construction | 2023 |
| Siddle Developments Ltd | Construction | 2024 |
| Sideways Honey Co Ltd | Wholesale & retail | 2025 |
| Sidhu & Sons Properties Ltd | Real estate | 2019 |
| Sidhu & Sons Transport (UK) Ltd | Administrative & support | 2011 |
| Sidra Property Ltd | Real estate | 2024 |
| Sift Merchant Company Limited | Manufacturing | 2017 |
| Sigma Building & Landscaping Limited | Construction | 2023 |
| Sigma Electrical Contractors Ltd. | Construction | 2001 |
| Sigma Parts Ltd | Wholesale & retail | 2026 |
| Sigma Transport Limited | Administrative & support | 2024 |
| Signature Careplus Ltd | Health & social care | 2024 |
| Signature Carpentry (EA) Ltd | Manufacturing | 2024 |
| Signature Professional Limited | Administrative & support | 2024 |
| Signature Properties Anglia Ltd | Real estate | 2020 |
| Signs for YOU Limited | Manufacturing | 1995 |
| Silent Sound Ltd | Information & communication | 2019 |
| Silk Cleaning Limited | Administrative & support | 2025 |
| Silkroots Limited | Wholesale & retail | 2024 |
| Silky DJU Hair Ltd | Other services | 2025 |
| Siluro Transport Ltd | Transport & logistics | 2023 |
| Silva Driving School Ltd | Education | 2023 |
| Silver Birch Consultancy Limited | Other services | 1998 |
| Silver Builders Merchants Ltd | Wholesale & retail | 2025 |
| Silver Greentech Air Systems Ltd | Construction | 2020 |
| Silver Hill Meadows Ltd | Real estate | 2024 |
| Silver Mine Bay Ltd | Real estate | 2025 |
| Silver Point Trading Limited | Real estate | 2026 |
| Silver Sabre Services Limited | Health & social care | 2026 |
| Silver Stone Land & Development Ltd | Real estate | 2012 |
| SILVEREYE42 Limited | Professional & scientific | 2018 |
| Silverman Grey Limited | Administrative & support | 2021 |
| Silviu-Stefan Ltd | Transport & logistics | 2025 |
| Silwy UK Ltd | Wholesale & retail | 2025 |
| SIMA&1 Limited | Real estate | 2025 |
| Simba Developments Ltd | Construction | 2023 |
| Simbabiz LP | | 2025 |
| Simbad Courier Rapid Ltd | Transport & logistics | 2023 |
| Simdav Ltd. | Administrative & support | 2011 |
| Simmons Site Engineering Services Ltd | Professional & scientific | 2015 |
| Simmons Stables Limited | Agriculture & fishing | 2016 |
| Simon Kerss Consultancy Limited | Professional & scientific | 2020 |
| Simon P Oram Ltd | Manufacturing | 2024 |
| Simon Shield Cars Limited | Wholesale & retail | 2001 |
| Simon Whalley Ltd | Health & social care | 2019 |
| Simple Click Solutions Limited | Information & communication | 2008 |
| Simplifii Ltd | Information & communication | 2025 |
| Simply Accounts & Tax Limited | Professional & scientific | 2011 |
| Simply Climate Control Limited | Manufacturing | 2014 |
| Simply Flowers Ipswich Limited | Wholesale & retail | 2014 |
| Simply Handy Co Ltd | Construction | 2023 |
| Simply Menopause Ltd | Health & social care | 2021 |
| Simply Moved Ltd | Transport & logistics | 2019 |
| Simply Wood (East) Limited | Construction | 2011 |
| Simpsonshaw Ltd | Real estate | 2020 |
| Simtim Properties Limited | Real estate | 2015 |
| Simtra Limited | Information & communication | 2006 |
| SIN BA HA Limited | Health & social care | 2022 |
| Single Lens Productions Limited | Information & communication | 2012 |
| Singleton Property Solutions Ltd | Real estate | 2025 |
| Sinhagad Limited | Health & social care | 2025 |
| Sinodun Internet Technologies Limited | Information & communication | 2010 |
| Sinsap D Limited | Financial services | 2025 |
| SIP Creative Studios Ltd | Construction | 2025 |
| SIP London Holdings Ltd | Financial services | 2020 |
| Sipan & Co Consultancy Ltd | Professional & scientific | 2025 |
| Sipho Couriers Ltd | Transport & logistics | 2024 |