| Spbb Resource Limited | Professional & scientific | 2018 |
| SPC Freight & Logistics Consultancy Ltd | Transport & logistics | 2026 |
| SPC Staycations Ltd | Real estate | 2024 |
| SPD Greengrocers Limited | Wholesale & retail | 2022 |
| SPE Connect Recruitment Limited | Administrative & support | 2019 |
| Speak-It Solutions Limited | Administrative & support | 1995 |
| Spear Logic Limited | Real estate | 2018 |
| Specialist Building Contracting Limited | Manufacturing | 2018 |
| Specialist Building Distribution Ltd | Extraterritorial | 1991 |
| Specialist Building Products Limited | Manufacturing | 1976 |
| Specialist Classic Spares Ltd | Wholesale & retail | 2021 |
| Specialist Environmental Projects Limited | Professional & scientific | 2018 |
| Specialist EV Projects Limited | Construction | 2024 |
| Specialist Fleet Services Limited | Administrative & support | 1993 |
| Specialist LAB Salt Limited | Wholesale & retail | 2005 |
| Specialist Medical Consulting Ltd | Health & social care | 2026 |
| Specialist Motor Finance Group Limited | Professional & scientific | 2015 |
| Specialist Motor Finance Limited | Financial services | 2005 |
| Specialist Motor Finance Services Limited | Professional & scientific | 2015 |
| Specialist Ophthalmology Services LLP | | 2012 |
| Specialist Orthopaedic Services Holdings Limited | Health & social care | 2017 |
| Specialist Orthopaedic Services Limited | Health & social care | 2010 |
| Specialist Outdoor Products Limited | Construction | 2000 |
| Specialist Property Asset Management (NO. 3) Ltd | Administrative & support | 2019 |
| Specialist Rifle Services Limited | Manufacturing | 2006 |
| Specialist Solutions UK Recruitment Ltd | Administrative & support | 2009 |
| Specialist Stocks and Finishing Limited | Manufacturing | 2009 |
| Specialist Vehicle Repairs Limited | Wholesale & retail | 2024 |
| Specspal Ltd | Health & social care | 2026 |
| Spectacles Direct Limited | Health & social care | 2008 |
| Spectrum Financial Solutions Limited | Financial services | 2008 |
| Spectrum Health Group Ltd | Hospitality | 2025 |
| Spectrum Homecare Ltd | Health & social care | 2021 |
| Spectrum Print Solihull Ltd | Manufacturing | 2014 |
| Spectrum Residents Management Company Limited | Households | 2019 |
| Spectus Systems Limited | Extraterritorial | 2005 |
| Speed DEL Ltd | Transport & logistics | 2013 |
| Speedwell Estates Limited | Real estate | 1945 |
| Speedwell Mudguards Limited | Manufacturing | 2019 |
| Speir Properties Limited | Real estate | 2025 |
| Spellman & Co Investment Group Limited | Professional & scientific | 2023 |
| Spencer Edwards Golf Limited | Arts & recreation | 2023 |
| Spencer Mccracken Boxing Ltd | Education | 2021 |
| Spencers Firewood Limited | Wholesale & retail | 2024 |
| SPF Electrical Ltd | Energy | 2014 |
| SPG Medical Services Ltd | Health & social care | 2020 |
| Sphink Ltd | Information & communication | 2022 |
| Spicecraft by Loyds Ltd | Hospitality | 2025 |
| Spices of Sheep Street Limited | Hospitality | 2025 |
| Spinach L & Broccoli K Marketing Ltd | Wholesale & retail | 2023 |
| Spinal Neurosurgery & GP Ltd | Health & social care | 2015 |
| Spink 'N' Span Window Cleaning Services Ltd | Administrative & support | 2021 |
| Spiracle Ltd | Health & social care | 2018 |
| Spirit of Birmingham Limited | Manufacturing | 2019 |
| Spiro Engineering Consultants Ltd | Professional & scientific | 2011 |
| Spitfire Bespoke Homes Limited | Construction | 2002 |
| Spitfire Homes (Ombersley) Limited | Construction | 2021 |
| Spitfire Homes (Sandvik) Limited | Construction | 2021 |
| Spitfire Homes (Wolston) Limited | Construction | 2021 |
| Spitfire Homes Group Limited | Construction | 2021 |
| Spitfire Homes Limited | Construction | 2022 |
| Spitfire Properties (Newhall) Limited | Construction | 2016 |
| Spkm Limited | Hospitality | 2023 |
| Splinterware Ltd | Manufacturing | 2020 |
| Spmw UK Ltd | Professional & scientific | 2021 |
| Spoak Ltd | Real estate | 2021 |
| Spoke Solutions Limited | Information & communication | 2016 |
| Spook Central Ltd | Wholesale & retail | 2024 |
| Spoondae Limited | Manufacturing | 2025 |
| Sport Development (UK) Limited | Arts & recreation | 2008 |
| Sport Surface Solutions Ltd | Administrative & support | 2025 |
| Sports Bar and Grill (Canary Wharf) Limited | Wholesale & retail | 2012 |
| Sports Bar and Grill Farringdon Limited | Wholesale & retail | 2010 |
| Sports Bar and Grill Victoria Limited | Wholesale & retail | 2009 |
| Sports Bar and Grill Waterloo Limited | Wholesale & retail | 2012 |
| Sports Core Services Limited | Professional & scientific | 2024 |
| Sports Regeneration Partnership Limited | Arts & recreation | 2011 |
| Sports Rehab Health & Performance Ltd | Health & social care | 2023 |
| Sports United Community Hub Ltd | Arts & recreation | 2025 |
| Spotlight Design Studios Limited | Professional & scientific | 2024 |
| Spotlight Leaders Academy Ltd | Administrative & support | 2024 |
| Spotted Octopus Recycling Limited | Water & waste | 2025 |
| SPR Project Management Services Ltd | Professional & scientific | 2015 |
| Sprayzen Limited | Wholesale & retail | 2021 |
| Springfield Pet Cremation Limited | Other services | 2024 |
| Sprint Active Education Limited | Education | 2013 |
| Sprite Energy Assessors Ltd | Professional & scientific | 2019 |
| SPS Coventry Limited | Health & social care | 2022 |
| SPS Managements Ltd | Extraterritorial | 2023 |
| SPT Building Limited | Construction | 2016 |
| Spud Mates Ltd | Wholesale & retail | 2025 |
| Spud YOU Like Ltd | Hospitality | 2024 |
| Spudgun Computing Limited | Administrative & support | 1998 |
| Spuds and Puds 0121 Ltd | Hospitality | 2025 |
| SPVY00033 Ltd | Other services | 2021 |
| Spyra Search Group Limited | Administrative & support | 2024 |
| Square Edge IT Solutions Ltd | Information & communication | 2024 |
| Square One Environmental Limited | Other services | 2024 |
| Square One Limited | Professional & scientific | 2008 |
| Square Real Estate Services Ltd | Real estate | 2017 |