| Sostac & Co Facades Ltd | Construction | 2021 |
| Sostene Ltd | Information & communication | 2019 |
| Sota Civil Engineering Ltd | Construction | 2025 |
| Sotech Studio Limited | Information & communication | 2022 |
| Soul Wardrobe Ltd | Professional & scientific | 2024 |
| Soulkitch Ltd | Hospitality | 2026 |
| Sound Designs Limited | Professional & scientific | 2005 |
| Sound Wave Master Group Ltd | Transport & logistics | 2017 |
| Soundcraft Pipe Organ Company Limited | Manufacturing | 2016 |
| Source 17 Ltd | Professional & scientific | 2022 |
| Sourcingx Limited | Administrative & support | 2017 |
| Sousa World Gourmet Limited | Hospitality | 2014 |
| South Coast Building Solutions Ltd | Construction | 2013 |
| South India Food Limited | Hospitality | 2026 |
| South Lincolnshire Developments Limited | Construction | 2017 |
| South Midlands PSV Ltd | Transport & logistics | 2012 |
| South View Tiney Childminding Ltd | Health & social care | 2026 |
| South Wales Transport (Neath) Ltd | Transport & logistics | 2004 |
| South Yorkshire Metals Ltd | Water & waste | 2008 |
| Southdale Limited | Construction | 1998 |
| Southern Counties Roofing Group Ltd | Construction | 2026 |
| Southern Pride Global Resources Limited | Public administration | 2025 |
| Southstream Services Limited | Manufacturing | 1989 |
| Sovco Limited | Wholesale & retail | 2010 |
| Sovereign Fields (Higham Ferrers) Management Company Limited | Households | 2004 |
| Sovllc Limited | Professional & scientific | 2022 |
| SP Business Advisory and Consulting Services Ltd | Professional & scientific | 2022 |
| SP Law Incorporating Martin Adams & Mccoll Ltd | Professional & scientific | 2014 |
| SP Law LLP | | 2008 |
| SP Motors Sales Ltd | Wholesale & retail | 2024 |
| SP Propco Limited | Real estate | 2020 |
| SP Recruitment Ltd | Administrative & support | 2024 |
| SP Rockhill & Co Ltd | Professional & scientific | 2021 |
| SP UK Sunshine Limited | Real estate | 2014 |
| SP Volta Ltd | Energy | 2025 |
| SP Web Design Limited | Information & communication | 2016 |
| Sp-Transport (UK) Ltd | Transport & logistics | 2014 |
| Spa Estates Limited | Real estate | 1964 |
| Space 24 Ltd | Construction | 2024 |
| Space Connect Limited | Information & communication | 2017 |
| Space Etcetera Ltd | Construction | 2025 |
| Space Grill Ltd | Wholesale & retail | 2013 |
| Space VAC Technologies Group Limited | Manufacturing | 2016 |
| Spaceage PVC Limited | Wholesale & retail | 2005 |
| Spaces Shaped Ltd | Construction | 2019 |
| Spactuk Ltd | Administrative & support | 2022 |
| Spaghetti Restaurant Limited | Hospitality | 2011 |
| Spare-Ring Ltd | Wholesale & retail | 2022 |
| Spark Line Energy Ltd | Construction | 2025 |
| Sparkle and Shine UK Cleaning Ltd | Administrative & support | 2020 |
| Sparkleklear Limited | Manufacturing | 2017 |
| Sparkles Services Ltd | Administrative & support | 2025 |
| Sparkletops Limited | Extraterritorial | 2011 |
| Sparks Fitness LAB Ltd | Arts & recreation | 2026 |
| Sparrow Consultant Group Ltd | Professional & scientific | 2025 |
| Sparrows Stores Ltd | Wholesale & retail | 2026 |
| Sparsis Leisure Limited | Arts & recreation | 2008 |
| Spartan Automotive Ltd | Real estate | 2021 |
| Spartan Finishing and Groundworks Ltd | Construction | 2026 |
| Sparti Assets (UK) Limited | Administrative & support | 2005 |
| Spatain Ltd | Health & social care | 2020 |
| SPB Coding Ltd | Information & communication | 2013 |
| SPB Property Solutions Ltd | Construction | 2026 |
| SPC General Construction Ltd | Construction | 2025 |
| Speak Worldwide Ltd | Wholesale & retail | 2026 |
| Spec International Ltd | Professional & scientific | 2015 |
| Special Touch Gifts Ltd | Wholesale & retail | 2022 |
| Specialist EWI & Rendering Ltd | Construction | 2022 |
| Specialist Housing Partnerships Ltd | Professional & scientific | 2026 |
| Specialist Skincare Limited | Health & social care | 2024 |
| Specialist Solutions (Central) Ltd | Administrative & support | 2005 |
| Specialty Polymer Solutions Limited | Wholesale & retail | 2025 |
| Speck Carpentry Limited. | Construction | 2000 |
| Spectrum Flair Limited | Manufacturing | 2002 |
| Spectrum Healthcare (UK) Limited | Other services | 2007 |
| Spectrum Northants Limited | Health & social care | 1999 |
| Spectrum Properties & Investment Ltd | Real estate | 2023 |
| Speech and Language Therapy Solutions Ltd | Health & social care | 2018 |
| Speedo Cars Ltd | Transport & logistics | 2018 |
| Speedtrek Holdings Ltd | Transport & logistics | 2016 |
| Speedy Contracts Ltd | Construction | 2026 |
| Speedy Haul Ltd | Transport & logistics | 2025 |
| Speedytrans LD Ltd | Transport & logistics | 2021 |
| Spence EDM Ltd | Professional & scientific | 2022 |
| Spencer 1508 Limited | Administrative & support | 2011 |
| Spencer Court Freehold (Rushden) Ltd | Households | 2013 |
| Spencer Developments Ltd | Construction | 2013 |
| Spencer Enterprises | Real estate | 2001 |
| Spencer Farms | | 1992 |
| Spencer House Properties Limited | Construction | 1975 |
| Spencer Tracy Limited | Construction | 2002 |
| Spencewood Interiors Limited | Manufacturing | 2010 |
| Spendol Ltd | Real estate | 2025 |
| Spenglerfox UK 2021 Limited | Financial services | 2021 |
| SPG Solutions (Northampton) Limited | Professional & scientific | 2013 |
| Spheretech Limited | Construction | 2014 |
| Spice 8 Ltd | Hospitality | 2019 |
| Spice Blue (Northampton) Limited | Hospitality | 2019 |
| Spice Lord Ltd | Hospitality | 2021 |
| Spicer Installations Limited | Construction | 2006 |