| SJD Bids Limited | Professional & scientific | 2018 |
| SJN Plumbing & Heating Limited | Construction | 2014 |
| Skira Solutions Ltd | Professional & scientific | 2023 |
| Slate Apps Limited | Information & communication | 2009 |
| Sloane South Kensington Developments Limited | Construction | 2025 |
| Smart Carping Limited | Agriculture & fishing | 2006 |
| Smart CXM Ltd | Information & communication | 2025 |
| Smart Homes Accommodation Limited | Hospitality | 2025 |
| Smart Prepared Systems Limited | Financial services | 1999 |
| Smart Viking Limited | Professional & scientific | 2025 |
| Smartway Cars Limited | Wholesale & retail | 2017 |
| Smartway Exchange Limited | Wholesale & retail | 2026 |
| SME Consultancy Limited | Information & communication | 2014 |
| Smith & Howard Limited | Construction | 2003 |
| SMN Consulting Services Limited | Professional & scientific | 2024 |
| Sneedle Props Ltd | Manufacturing | 2019 |
| SNM (Hartley) Ltd | Hospitality | 2022 |
| Social Data Science Ltd | Professional & scientific | 2022 |
| Sojodrell Ltd | Arts & recreation | 2021 |
| Solar Decisions Limited | Wholesale & retail | 2024 |
| Solent Yacht Chandlery Ltd | Wholesale & retail | 2020 |
| Soleus Physiotherapy Ltd | Health & social care | 2019 |
| Sonoda Ltd | Real estate | 2022 |
| Sotif Solutions Ltd | Information & communication | 2010 |
| South East Design Company (UK) Ltd | Professional & scientific | 2016 |
| South Solent Sports Ltd | Wholesale & retail | 2022 |
| Southern DRY Riser Testing Ltd | Manufacturing | 2011 |
| Southview (Hants) Limited | Real estate | 2012 |
| Southview Drylining Limited | Construction | 2016 |
| Space Comm Systems Limited | Manufacturing | 2023 |
| Sparande Ltd | Information & communication | 2026 |
| Spark-E Automotive Limited | Wholesale & retail | 2022 |
| Spartan Auto Limited | Wholesale & retail | 2021 |
| Spartan Construction Group Limited | Construction | 2018 |
| Spartan Holdings Ltd | Financial services | 2024 |
| Spartan Mechanical Ltd | Construction | 2011 |
| SPD Industries Limited | Manufacturing | 2021 |
| SPE Engineers Limited | Construction | 2007 |
| Speak-More Ltd | Professional & scientific | 2019 |
| Spectral Creative Limited | Manufacturing | 2011 |
| Speedwell Performance Limited | Wholesale & retail | 2024 |
| Spraytech Car Body Repairs Ltd | Wholesale & retail | 2018 |
| Square in the Air Communications Ltd | Arts & recreation | 2006 |
| Ssvv Estate Ltd | Real estate | 2023 |
| ST Construction Services Limited | Construction | 2024 |
| ST John's Preschool Hook Ltd | Education | 2018 |
| ST Johns HW Ltd | Hospitality | 2018 |
| St.Neots(Eversley)Limited | Education | 1955 |
| Stanbury View (Parklands) Management Company Limited | Households | 2021 |
| Stanhope Gardens (Wellesley) (Block a) Residents Management Company Limited | Households | 2023 |
| Stanhope Gardens (Wellesley) (Block F) Residents Management Company Limited | Households | 2023 |
| Stanhope Gardens (Wellesley) (Block G) Residents Management Company Limited | Households | 2023 |
| Stanhope Gardens (Wellesley) (Blocks B-D) Residents Management Company Limited | Households | 2023 |
| Stapeley Estates Limited | Real estate | 2018 |
| Steadmate Ltd | Information & communication | 2025 |
| Steed Bespoke Tailors Limited | Manufacturing | 2024 |
| Sterling Lombard Limited | Information & communication | 2023 |
| Stern Farms Limited | Agriculture & fishing | 1977 |
| Sterrybridge Autos Limited | Wholesale & retail | 2010 |
| Sterrybridge Properties Limited | Real estate | 2024 |
| Steven Associates Limited | Hospitality | 1996 |
| Still-Live Media Limited | Professional & scientific | 2016 |
| Stocton Consulting Limited | Professional & scientific | 2007 |
| Stodl Ltd | Information & communication | 2023 |
| Stoked Projects Limited | Real estate | 2018 |
| Stolen Goat Ltd | Other services | 2012 |
| Stone Circle Ltd | Arts & recreation | 2024 |
| Stone Directory Limited | Manufacturing | 2013 |
| Stone Dynamics Limited | Manufacturing | 2022 |
| Stonelea Grove Management Company Limited | Households | 2003 |
| Stoneridge Camper Conversions Ltd | Wholesale & retail | 2026 |
| STONES4GARDENS Ltd | Wholesale & retail | 2020 |
| Stortrec UK Ltd | Information & communication | 2009 |
| Strand Investment Management Limited | Financial services | 2024 |
| Strand Investment Partners LLP | | 2024 |
| Strata Geotech Limited | Construction | 2026 |
| Stratos Engineering Solutions Ltd | Information & communication | 2025 |
| Strive Fitness Ltd. | Arts & recreation | 2024 |
| Strive Studio Ltd | Arts & recreation | 2026 |
| Structuring Services Limited | Professional & scientific | 2009 |
| Studio JT Ltd | Arts & recreation | 2025 |
| Style Guys Ltd | Wholesale & retail | 2019 |
| Sublime Consulting Limited | Real estate | 2011 |
| SUE Prince Resourcing Ltd | Administrative & support | 2016 |
| Sugar Electrical Contractors Ltd | Construction | 2022 |
| Summit Sales Promotion Limited | Professional & scientific | 1993 |
| Sunaru Consultants Limited | Other services | 1995 |
| Sunflower Music Limited | Information & communication | 2000 |
| Sunwood Drive Residents Association Limited | Households | 2011 |
| Sunwood Holdings Limited | Real estate | 2020 |
| Supercell 365 Limited | Information & communication | 2018 |
| Supercell Group Limited | Financial services | 2020 |
| Supercell Holdings Limited | Real estate | 2020 |
| Superfolk Films Limited | Information & communication | 2021 |
| Superfolk Limited | Information & communication | 2013 |
| Supreme Wheels Direct Ltd | Wholesale & retail | 2010 |
| SURE4DOORS Limited | Wholesale & retail | 2018 |
| Surface Products (Europe) Limited | Wholesale & retail | 2015 |
| Surrey Gates & Automation Limited | Extraterritorial | 2003 |
| Surrey Plumbing & Heating Ltd | Construction | 2006 |