| Sparkhouse Metering Limited | Construction | 2019 |
| Sparks of Metal Ltd | Information & communication | 2025 |
| Sparkstarters Limited | Professional & scientific | 2024 |
| Spawn Public Relations Ltd | Professional & scientific | 2024 |
| SPB Civil Engineering Ltd | Construction | 2018 |
| SPB Developments Ltd | Real estate | 2025 |
| Speak OUT Group Limited | Administrative & support | 2023 |
| Speakerella Group Ltd | Education | 2018 |
| Speakjava Enterprises Limited | Professional & scientific | 2021 |
| Specialist Detailing Limited | Wholesale & retail | 2018 |
| Specialist Environmental Solutions Ltd | Construction | 2012 |
| Spectrum Circle Ltd | Professional & scientific | 2020 |
| Spectrum Infrastructure Limited | Information & communication | 2016 |
| Speed Sourcing Limited | Wholesale & retail | 2024 |
| Speedy Spanners (Horndean) Limited | Manufacturing | 2016 |
| Speltham Hill Properties Limited | Real estate | 2012 |
| Spencer Mills Construction Limited | Construction | 2019 |
| Spice Spice Ltd | Hospitality | 2025 |
| Spice-Box Indian Ltd | Hospitality | 2019 |
| Spinnaker GAS Ltd | Construction | 2024 |
| Spinnaker Site Services Ltd | Construction | 2020 |
| Spinnaker TNE Partners Limited | Professional & scientific | 2022 |
| Spinnakergb Ltd | Real estate | 2025 |
| Spire Interactive Limited | Information & communication | 2018 |
| Spire Wood (Denmead) Management Company Limited | Households | 2017 |
| Spirende Limited | Professional & scientific | 2015 |
| Spirit of 86 Ltd | Professional & scientific | 2021 |
| Spirit of Legends Limited | Wholesale & retail | 2025 |
| Spirit TCG Ltd | Wholesale & retail | 2026 |
| Spoilt Ballot Theatrical Productions Limited | Arts & recreation | 2019 |
| Sporting Clays Limited | Arts & recreation | 2012 |
| Sports Advice Group Limited | Arts & recreation | 2023 |
| Sports for Life Limited | Arts & recreation | 2016 |
| Sports Group Consulting Ltd | Professional & scientific | 2019 |
| Spotless Southern Limited | Administrative & support | 2018 |
| Spotty Dog MAN and Van Ltd | Transport & logistics | 2015 |
| SPR Portfolio Ltd | Real estate | 2025 |
| SPR Roofing Contractors Ltd | Construction | 2020 |
| Spraytrainsuk Ltd | Construction | 2025 |
| Spriggs & SON Ltd | Real estate | 2024 |
| Spring Media Partners Limited | Professional & scientific | 2025 |
| Springwood Preschool and Nursery Ltd | Education | 2022 |
| Squared Building Contractors Ltd | Construction | 2023 |
| Squirrels Nursery Limited | Health & social care | 2013 |
| SR Bridgeway Capital Limited | Real estate | 2025 |
| SR Training Ltd | Other services | 2019 |
| SRC Repairs Ltd | Extraterritorial | 2024 |
| SRH Corp Limited | Education | 2025 |
| SS Accident Repair Centre Limited | Wholesale & retail | 2022 |
| SS Collins Limited | Arts & recreation | 2008 |
| SS Property Developments Hampshire Limited | Construction | 2026 |
| SSA Cars Limited | Wholesale & retail | 2020 |
| SSS Official Limited | Administrative & support | 2019 |
| Sswc Limited | Professional & scientific | 2025 |
| ST Brickwork Ltd | Construction | 2026 |
| ST John Electrics Limited | Construction | 2022 |
| ST Matthews Court NO.2 Residents Company Limited | Households | 1988 |
| Stable Financial Planning Limited | Financial services | 2020 |
| Stable Mews (Church Farm) Management Company Limited | Real estate | 2023 |
| Stable Mews RH7 Ltd | Real estate | 2024 |
| Stable Precision Holdings Limited | Financial services | 2006 |
| Stack-Cup Group Holdings Limited | Financial services | 2018 |
| Stack-Cup UK Limited | Manufacturing | 2013 |
| Stadium Homes Limited | Real estate | 2016 |
| Stafford Court Freehold Ltd | Real estate | 2020 |
| Stafford Court Management Services Ltd | Households | 2021 |
| Stafford ROW Limited | Administrative & support | 2024 |
| Staffwise Collective Limited | Administrative & support | 2025 |
| Stagegrand Limited | Arts & recreation | 2026 |
| Stairlift Service and Repair Limited | Other services | 2012 |
| Stakes Hill Financial Services Limited | Financial services | 2021 |
| Stakes Hill Road Management Limited | Households | 1974 |
| Stan Interiors Limited | Construction | 2025 |
| Stand Clear Properties Limited | Real estate | 2014 |
| Standing Ground Ltd | Other services | 2021 |
| Stanley Design & Build Limited | Construction | 2022 |
| Stansted Garage Ltd | Wholesale & retail | 2025 |
| Stanton Moss Ltd | Hospitality | 2023 |
| Stanton Watchcraft Ltd | Wholesale & retail | 2025 |
| Starbax Limited | Real estate | 2001 |
| Starbell Trading Limited | Wholesale & retail | 2017 |
| Stardust Leisure (2000) Limited | Arts & recreation | 2000 |
| Starex Resource Solutions Limited | Administrative & support | 2023 |
| Starfish Consulting Ltd | Wholesale & retail | 2018 |
| Starfish Creative Design Limited | Professional & scientific | 2004 |
| Starglaze Windows (Hampshire) Limited | Construction | 1982 |
| Stark Arts Limited | Other services | 2023 |
| Starline Marine Cleaning Limited | Administrative & support | 2022 |
| Starman Media Ltd | Wholesale & retail | 2026 |
| Stars Accounts Ltd | Professional & scientific | 2024 |
| Stars One Accounting Limited | Professional & scientific | 2024 |
| Stay Local Publishing Limited | Information & communication | 2009 |
| Steak and Lobster Limited | Hospitality | 2015 |
| Steel Private Investment Partners LP | | 2024 |
| Steep Properties Limited | Administrative & support | 1997 |
| Steeple Court Manor Weddings and Events Limited | Hospitality | 2022 |
| Stellar Electrical Limited | Construction | 2017 |
| Step Automotive Limited | Professional & scientific | 2025 |
| Stephen Bates Property Ltd | Real estate | 2024 |
| Stephen Canning Limited | Information & communication | 2020 |