| Solus Apartments Management Co Ltd | Households | 2021 |
| SOLUTION4LODGING Ltd | Real estate | 2024 |
| Solutionforge Limited | Extraterritorial | 2011 |
| Solutions MJG Ltd | Wholesale & retail | 2025 |
| SOLUTIONS2GROW Limited | Administrative & support | 2021 |
| Solyzaa Ltd | Wholesale & retail | 2026 |
| Solé FHP Ltd | Health & social care | 2026 |
| Somat Cleaning Services Ltd | Administrative & support | 2023 |
| Sombre Limited | Transport & logistics | 2022 |
| Somerton Meadows Residents Management Company Limited | Households | 2015 |
| Something Beckons Ltd | Information & communication | 2008 |
| Something to AIM at Ltd | Professional & scientific | 2009 |
| Sona Roadshow Ltd | Arts & recreation | 2025 |
| Sonder Electrical Ltd | Construction | 2023 |
| Songbay Limited | Information & communication | 2011 |
| Sonia Bruno's Ltd | Other services | 2026 |
| Sonia Driving School Ltd | Education | 2026 |
| Sonic Cinema Ltd | Information & communication | 2021 |
| Sonic Security (UK) Limited | Administrative & support | 2002 |
| Sophia's Spares and Salvage Ltd | Wholesale & retail | 2023 |
| Sophiavalytrans Ltd | Transport & logistics | 2019 |
| Sophie B Logistics Ltd | Transport & logistics | 2023 |
| Sopmar Contruction Ltd | Construction | 2022 |
| Sopmar Ltd | Construction | 2016 |
| Sopp and Sopp Limited | Transport & logistics | 2003 |
| Soraya Productions Limited | Information & communication | 2021 |
| Sorcam Ltd | Transport & logistics | 2016 |
| Sorgax Ltd | Wholesale & retail | 2020 |
| Sorin Solution Ltd | Transport & logistics | 2022 |
| Sorinache Ltd | Health & social care | 2016 |
| Sort It.Biz Limited | Information & communication | 2003 |
| Sotera Ltd | Financial services | 2024 |
| Soto Logistics Ltd | Transport & logistics | 2025 |
| Soul & Sanctuary Limited | Real estate | 2024 |
| Soul Essence Ltd | Professional & scientific | 2014 |
| Soul Happy Shop Community Interest Company | Wholesale & retail | 2019 |
| Sound Accounts Ltd | Professional & scientific | 2015 |
| Sound Achievements (Cowgate) Limited | Wholesale & retail | 2007 |
| Sound Building Contractors Ltd | Construction | 2017 |
| Sound Digital Limited | Information & communication | 2014 |
| Sound Factory Entertainment Limited | Arts & recreation | 2024 |
| Sound Financial Solutions Ltd | Financial services | 2003 |
| Sound Practice Services LLP | | 2025 |
| Sounds Accounts Ltd | Professional & scientific | 2019 |
| Sounds Ayce Ltd | Information & communication | 2026 |
| Sourcd T.R.W. Ltd | Administrative & support | 2024 |
| Source Platforms Ltd | Information & communication | 2025 |
| Sourcebean Ltd | Information & communication | 2020 |
| Sourcing Solutions Peterborough Limited | Wholesale & retail | 2015 |
| South African Tours Limited | Administrative & support | 2007 |
| South Lincs Foundry Limited | Manufacturing | 2008 |
| South Roots Ltd | Wholesale & retail | 2024 |
| South West Art Work Community Interest Company | Arts & recreation | 2008 |
| South Wigston Residents Company Limited | Households | 2000 |
| Southern Cable and Utilities Limited | Information & communication | 2018 |
| Southern Coastal Homes Ltd | Real estate | 2024 |
| Southern Investment Property Group Ltd | Real estate | 2022 |
| Southernwood Developments Ltd | Construction | 2023 |
| Southfield Business Park Limited | Extraterritorial | 1997 |
| Southfield Housing Development Limited | Extraterritorial | 2017 |
| Southy Commercials Ltd. | Wholesale & retail | 2023 |
| Sovereign (Peterborough) Ltd | Professional & scientific | 2013 |
| Sovereign Landscapes Limited | Administrative & support | 2003 |
| Sovereign Oak Holdings Ltd | Financial services | 2025 |
| Sovereign Properties (England) Ltd | Real estate | 2021 |
| Sovereign Property Works Ltd | Construction | 2025 |
| Sovereigngate Property Management Limited | Households | 2001 |
| Soxhlet Limited | Health & social care | 2024 |
| SP Insurance Services Limited | Financial services | 2022 |
| SP Properties (Peterborough) Ltd | Real estate | 2024 |
| Spa Repairs Limited | Other services | 2019 |
| Space 2 (UK) Ltd | Professional & scientific | 2006 |
| Space Carz Ltd | Wholesale & retail | 2022 |
| Spaceman Cleaning Services Ltd | Administrative & support | 2026 |
| Spaces Please Limited | Information & communication | 2025 |
| Spakas Limited | Transport & logistics | 2025 |
| Spalding Air Conditioning Services Limited | Construction | 2008 |
| Spalding Coldstore 2 Ltd | Transport & logistics | 2024 |
| Spalding Coldstore Ltd | Transport & logistics | 2024 |
| Spalding Commercials Ltd. | Wholesale & retail | 2016 |
| Spalding Developments Ltd | Construction | 2020 |
| Spalding United Football Club (2017) Ltd | Arts & recreation | 2017 |
| Spalding Water Taxi Company Limited | Transport & logistics | 2004 |
| Span Technical Ltd | Construction | 2008 |
| Spanscan Ltd | Professional & scientific | 2020 |
| Spar Mill Road Ltd | Wholesale & retail | 2012 |
| SPARES4REPAIRS Automotive Ltd | Wholesale & retail | 2025 |
| Sparkle & Shine Boutique Ltd | Wholesale & retail | 2024 |
| Sparkle & Shine by Magdalena Ltd | Administrative & support | 2026 |
| Sparkly Hand Car Wash Ltd | Administrative & support | 2019 |
| Sparko Kleen Ltd | Wholesale & retail | 2018 |
| Sparks & Sons Property Development Ltd | Construction | 2016 |
| Sparks Electrical Engineers Limited | Construction | 2025 |
| Sparks Pubs Ltd | Hospitality | 2025 |
| Sparrow Haul Ltd | Transport & logistics | 2024 |
| Spart LW Ltd | Construction | 2026 |
| Spartan Install Ltd | Construction | 2025 |
| SPD Peterborough Ltd | Administrative & support | 2024 |
| Speak UP Academy UK CIC | Education | 2025 |
| Speakfirst Limited | Administrative & support | 2003 |