| Sparshatts Group Limited | Wholesale & retail | 2019 |
| Sparshott Marine Ltd | Professional & scientific | 2022 |
| Sparta Shield Ltd | Financial services | 2025 |
| Spartacus Homes Limited | Real estate | 2026 |
| Spartan Residential Limited | Real estate | 2023 |
| Spartans Gym Southampton Limited | Arts & recreation | 2011 |
| SPB Plumbing Ltd | Construction | 2026 |
| SPC Industrial Services Limited | Extraterritorial | 2013 |
| SPC Roofing & Carpentry Ltd | Extraterritorial | 2016 |
| SPD Accountants Limited | Professional & scientific | 2005 |
| Spear One Ltd | Information & communication | 2025 |
| Spec House Ltd | Other services | 2016 |
| Spec Lucas Limited | Construction | 2019 |
| Specialised Polymer Engineering Limited | Manufacturing | 2001 |
| Specialist Freeholds Ltd | Households | 2021 |
| Specialist Homes Limited | Construction | 2022 |
| Specialist Insurance Agency (Holdings) Limited | Real estate | 2004 |
| Specialist Neurology Services Limited | Health & social care | 2013 |
| Specialist Rentals Limited | Real estate | 1994 |
| Specialist Schools Trust Ltd | Education | 2011 |
| Specialist Skills Ltd | Construction | 2024 |
| Specialist Sports Creation Limited | Wholesale & retail | 2022 |
| Specialist Sports Group Holdings Ltd | Financial services | 2024 |
| Specialist Sports Group Limited | Wholesale & retail | 2014 |
| Specialist Sports Limited | Wholesale & retail | 1992 |
| Specialist Thermal Ltd | Construction | 2023 |
| Speciality Engineering Chemicals Limited | Manufacturing | 1999 |
| Specificlean Services Limited | Administrative & support | 2024 |
| Spectacled OWL Training and Development Consultancy Ltd | Professional & scientific | 2019 |
| Spectrum Building Solutions Limited | Construction | 2023 |
| Spectrum Centre for Independent Living CIC | Health & social care | 1987 |
| Spectrum Continuing Care CIC | Health & social care | 2009 |
| Spectrum Courier Ltd | Transport & logistics | 2018 |
| Spectrum Garment Care Limited | Other services | 2012 |
| Spectrum IT Recruitment (South) Limited | Administrative & support | 2008 |
| Spectrum Signs & Workwear Ltd | Wholesale & retail | 2005 |
| Spectrum Sisters Limited | Health & social care | 2025 |
| Speed of Think Publishing Ltd | Information & communication | 2016 |
| Speeder Systems Ltd | Professional & scientific | 2021 |
| Speedwell House Limited | Real estate | 2017 |
| Speedwell Training Limited | Transport & logistics | 2025 |
| Speedy Driver Ltd | Transport & logistics | 2011 |
| Speedy INT Limited | Hospitality | 2025 |
| Speedy Rollers Ltd | Wholesale & retail | 2023 |
| Speedypack Ltd | Wholesale & retail | 1993 |
| Spelt & RYE Ltd | Manufacturing | 2025 |
| Spencer Frederick Building Contractors Limited | Construction | 2012 |
| Spencer Rhodes Limited | Financial services | 2023 |
| Spencerharley Ltd | Real estate | 2021 |
| Spencerharley Vehicle Rentals Ltd | Transport & logistics | 2023 |
| Sperrings Limited | Other services | 2008 |
| SPF Jigsaw Ltd | Agriculture & fishing | 2016 |
| Sphearx Limited | Information & communication | 2024 |
| Spice 87 Ltd | Hospitality | 2025 |
| Spice Cave Limited | Manufacturing | 2025 |
| Spice Merchant Henley Limited | Hospitality | 2023 |
| Spice N Grill Southampton Ltd | Hospitality | 2026 |
| Spiced Samosa Ltd | Manufacturing | 2023 |
| Spiceworldotg Ltd | Hospitality | 2023 |
| Spicey HUT Ltd | Hospitality | 2025 |
| Spicey Mint Ltd | Hospitality | 2018 |
| Spicy Dee's Hot Sauce Ltd | Manufacturing | 2024 |
| Spidermind Games Ltd | Information & communication | 2015 |
| Spill Management Operations Limited | Extraterritorial | 2016 |
| Spillconsult Ltd | Professional & scientific | 2012 |
| Spillconsult Services - Aberdeen Ltd | Extraterritorial | 2018 |
| Spindlewood Developments Ltd | Construction | 2026 |
| Spindlewood Estates Limited | Real estate | 2024 |
| Spindrift Pathology Limited | Health & social care | 2019 |
| Spindrift Sail Ltd | Information & communication | 2015 |
| Spinetic Energy Limited | Manufacturing | 2012 |
| Spinnaker House Property Management Ltd | Households | 2025 |
| Spinz Limited | Health & social care | 2022 |
| Spiral Weld Limited | Manufacturing | 1989 |
| Spire Close Management Limited | Real estate | 2010 |
| Spire Court Beckenham Limited | Households | 2007 |
| Spire Group Holdings Limited | Professional & scientific | 2026 |
| Spire Tire and Auto Limited | Wholesale & retail | 1994 |
| Spiridion Limited | Construction | 2019 |
| Spirit Motorhomes Limited | Wholesale & retail | 2025 |
| Spirit of Health Limited | Health & social care | 2000 |
| Spiteri Music Limited | Information & communication | 2017 |
| Spitfire Ceilings Limited | Construction | 2013 |
| Spitfire Court Properties Limited | Real estate | 2003 |
| Spitfire Garage (Autotekk) Ltd | Wholesale & retail | 2009 |
| Spitfire Garage Ltd | Wholesale & retail | 2013 |
| Spitfire Metal Work Ltd | Manufacturing | 2017 |
| Spitfire Property Services Ltd | Households | 2025 |
| Splash Bro's Valeting & Detailing Ltd | Wholesale & retail | 2022 |
| Splendid Marketing Ltd | Information & communication | 2025 |
| Spoilt Broth Limited | Information & communication | 2012 |
| Spokes of Bagshot Limited | Wholesale & retail | 2014 |
| Sport Republic Cisset Mali Ltd. | Financial services | 2023 |
| Sport Republic Holding Ltd. | Financial services | 2021 |
| Sport Republic Nominee Limited | Financial services | 2022 |
| Sport Republic North America (UK) Intermediate Holding Ltd. | Financial services | 2022 |
| Sport Republic Turkey Ltd. | Financial services | 2022 |
| Sport Republic UK Ltd. | Financial services | 2021 |
| Sportfit Support Services Limited | Health & social care | 2012 |
| Sportsboat World Limited | Administrative & support | 2012 |