| Spill Doctor UK Limited | Professional & scientific | 2002 |
| Spilman-Penn Limited | Agriculture & fishing | 2018 |
| Spinaclean Ltd | Wholesale & retail | 2002 |
| Spinadisc Records Limited | Wholesale & retail | 2019 |
| Spinney Hill (Oakham) Management Company Limited | Households | 2015 |
| Spinney Student Lettings Ltd | Households | 2016 |
| Spinwell Global Limited | Other services | 2011 |
| Spinwell Global Risk & Securities Limited | Administrative & support | 2015 |
| Spires Decorating & Specialist Coatings Ltd | Construction | 2019 |
| Spitfire Engineering Services Ltd | Manufacturing | 2005 |
| Spitfire Group Ltd | Professional & scientific | 2023 |
| SPL Convenience Store Ltd | Wholesale & retail | 2020 |
| Splash Business Ltd | Professional & scientific | 2026 |
| Splice N Data Ltd | Information & communication | 2014 |
| SPM IP Ltd | Professional & scientific | 2025 |
| Spokes Education Ltd | Professional & scientific | 2013 |
| Sponge BOB Transport Ltd | Transport & logistics | 2023 |
| Spony Care Ltd | Health & social care | 2014 |
| Sport Road Ltd | Wholesale & retail | 2024 |
| SPORT4FITNESS CIC | Education | 2014 |
| Sporting Cuts Limited | Other services | 2020 |
| Sportish Limited | Wholesale & retail | 2024 |
| Sports & Stadia Services Holdings Limited | Other services | 2024 |
| Sports & Stadia Services Limited | Other services | 2002 |
| Sports Courts UK Limited | Arts & recreation | 2000 |
| Sports for the Community CIC | Education | 2025 |
| Sports Purpose Limited | Wholesale & retail | 2017 |
| Sportsguard Direct Limited | Extraterritorial | 1998 |
| Sportstextiles.Com Limited | Information & communication | 2000 |
| Sportsview Limited | Administrative & support | 1999 |
| Sportswill Limited | Wholesale & retail | 2026 |
| Spotd Group Limited | Professional & scientific | 2026 |
| Spotlight Dance Ltd | Education | 2025 |
| Spotlight Interiors Ltd | Wholesale & retail | 2024 |
| Spotlight Photo Events Limited | Professional & scientific | 2010 |
| Spout Bath Toys Ltd | Manufacturing | 2024 |
| Spratton Community Club CIC | Hospitality | 2025 |
| Spread Catering Ltd | Hospitality | 2019 |
| Spreading Health Care Services Limited | Professional & scientific | 2017 |
| Spring Gardens (Burton Latimer) Management Company Limited | Households | 2017 |
| Spring Gate Health Care Ltd | Public administration | 2019 |
| Spring Hill Park Development LLP | | 2014 |
| Spring Learning Centre | Education | 2013 |
| Spring Line Limited | Manufacturing | 1982 |
| Spring Water Farm Stays Ltd | Hospitality | 2025 |
| Springfield Farm Campsite Ltd | Hospitality | 2021 |
| Springhill Kitchens & Bedrooms Limited | Wholesale & retail | 2012 |
| Springhill Life Care Ltd | Health & social care | 2023 |
| Springhill Marketing Limited | Professional & scientific | 2016 |
| Spruth Magers Limited | Extraterritorial | 2015 |
| SPS Plastering Contractors Limited | Construction | 2022 |
| SPS Tooling Ltd | Wholesale & retail | 2019 |
| SPS:2020 Ltd | Professional & scientific | 2020 |
| Spumy Group Ltd | Wholesale & retail | 2025 |
| SQ1 Digital Ltd | Information & communication | 2024 |
| Sqcdf Ltd | Construction | 2021 |
| Sqer Ltd | Wholesale & retail | 2019 |
| Square Qube Ltd | Manufacturing | 2022 |
| Squareline Driving Ltd | Transport & logistics | 2019 |
| Squareline Transport Ltd | Transport & logistics | 2020 |
| Squeaky Clean Northampton Ltd | Administrative & support | 2025 |
| Squires JW Ltd | Manufacturing | 2025 |
| Squires of Ashley Limited | Agriculture & fishing | 2016 |
| Squirrel Factor Limited | Professional & scientific | 2025 |
| Squizzas Global Limited | Wholesale & retail | 2017 |
| Squizzas Logistics Ltd | Wholesale & retail | 2015 |
| Squizzas! Ltd | Wholesale & retail | 2015 |
| SR Anshika Traders Ltd | Wholesale & retail | 2011 |
| SR Books (Northants) Ltd | Professional & scientific | 2025 |
| SR Northants Ltd | Real estate | 2025 |
| SR Trading Ltd | Wholesale & retail | 2026 |
| SR Wellness Group Limited | Health & social care | 2026 |
| SR3H Ltd | Information & communication | 2026 |
| SRA Consultancy Services Limited | Professional & scientific | 2007 |
| SRA Contracting (UK) Limited | Extraterritorial | 2012 |
| Sraavanam Ltd | Information & communication | 2017 |
| Sras Property Ltd | Real estate | 2024 |
| SRB Events Limited | Administrative & support | 2012 |
| SRI NKB Properties Limited | Real estate | 2025 |
| SRI Technologies PVT Ltd | Information & communication | 2023 |
| Sriharsh Limited | Wholesale & retail | 2020 |
| Sriram Technologies Ltd | Information & communication | 2012 |
| Srjp Limited | Wholesale & retail | 2025 |
| SRK North Ltd | Wholesale & retail | 2019 |
| SRN Associates (Consulting) Limited | Professional & scientific | 2009 |
| SRN Associates Limited | Real estate | 2004 |
| SRN Transport Limited | Transport & logistics | 2021 |
| Srvm Ltd | Wholesale & retail | 2016 |
| SRZ3 Limited | Real estate | 2023 |
| SS Drywall Ltd | Construction | 2015 |
| SS Enforcement Ltd | Administrative & support | 2026 |
| SS Fitness Limited | Arts & recreation | 2018 |
| SS Global Services Ltd | Information & communication | 2018 |
| Ss&A Services Ltd | Hospitality | 2022 |
| SSB Hair Limited | Other services | 2025 |
| SSC Homes Ltd | Real estate | 2021 |
| Sservices Ltd | Administrative & support | 2022 |
| SSF Design & Build Ltd | Construction | 2021 |
| Ssfbn Limited | Wholesale & retail | 2025 |
| Ssharfi & Sons Ltd | Hospitality | 2021 |