| Sharing Parenting an Adlerian Approach to Parenting Community Interest Company | Education | 2009 |
| Sharman Grimwade Ltd | Professional & scientific | 2015 |
| Sharp Regulatory Consulting Limited | Professional & scientific | 2020 |
| Shaun Deacon Windows Limited | Construction | 2004 |
| Sheppard R & D Consultancy Ltd | Professional & scientific | 2018 |
| Shield Defence Group Ltd | Information & communication | 2026 |
| Shop With AMY Limited | Wholesale & retail | 2025 |
| Shortcastle Bloodstock Limited | Agriculture & fishing | 2025 |
| Shots Group Ltd | Manufacturing | 2013 |
| Shrewsbury Road Limited | Information & communication | 2018 |
| SHS One Technologies Ltd | Professional & scientific | 2024 |
| Shylocked | Arts & recreation | 2022 |
| Siametric Systems Limited | Information & communication | 2017 |
| Sico Consulting Ltd | Professional & scientific | 2019 |
| Sier Logistics Limited | Transport & logistics | 2015 |
| Signature Holidays Limited | Real estate | 2012 |
| Silk Fusion Limited | Wholesale & retail | 2026 |
| Silly School Education Limited | Education | 2023 |
| Silver Fern Farms (UK) Limited | Wholesale & retail | 1968 |
| Silver FOX PUB Ltd | Hospitality | 2024 |
| Silver Stag Consulting Ltd | Professional & scientific | 2023 |
| Silver Throne Martial Arts CIC | Education | 2025 |
| Silverwood Properties Suffolk Ltd | Households | 2022 |
| Silverwood Services Ltd | Wholesale & retail | 2020 |
| Silviu Dragan Ltd | Transport & logistics | 2020 |
| SIM Local (UK) Ltd | Information & communication | 2012 |
| Simon & Jacque Pettitt Window Cleaning Service Limited | Other services | 2003 |
| Simon Bailey Ministries Ltd | Other services | 2026 |
| Simon Finney Cleaning Services Ltd | Administrative & support | 2007 |
| Simon Pearce Racing Ltd | Arts & recreation | 2019 |
| Simply Great Thai Food Limited | Hospitality | 2023 |
| Sinergy Fitness Ltd | Arts & recreation | 2024 |
| Singsational Kids Limited | Education | 2025 |
| Siobhan Gilligan Mctimoney Animal Chiropractor Limited | Other services | 2018 |
| Sionics Limited | Manufacturing | 2006 |
| Sirk Investments Limited | Financial services | 1987 |
| Site Skim Plastering Ltd | Construction | 2020 |
| SIX Mile Bottom Farms LLP | | 2007 |
| SJ Peck Consultants Limited | Administrative & support | 2024 |
| SKYLINE247 Limited | Transport & logistics | 2019 |
| SM International Logistics for Equines (Smile) Ltd | Agriculture & fishing | 2022 |
| Small Fuels Ltd | Wholesale & retail | 2022 |
| Smart Techno Limited | Wholesale & retail | 2025 |
| Smarter Hosting Ltd | Hospitality | 2025 |
| Smarter Metering Group Limited | Manufacturing | 2012 |
| SMB Catering Services Ltd | Hospitality | 2024 |
| SMI Drug Discovery Limited | Professional & scientific | 2018 |
| Smile and Facial Aesthetics Ltd | Health & social care | 2013 |
| Smiley Carpentry Limited | Construction | 2020 |
| Smith & Spring Properties Ltd | Real estate | 2022 |
| Smithco Electrical Limited | Construction | 2023 |
| Sofiegeorgia Limited | Other services | 2024 |
| Softlens Technologies Limited | Information & communication | 2025 |
| Softtrain Cloud Ltd | Information & communication | 2022 |
| Soggy Software Limited | Information & communication | 2017 |
| Soham Car Sales Ltd | Wholesale & retail | 2026 |
| Soham Commercial Properties Limited | Real estate | 2021 |
| Soham Properties Limited | Real estate | 2015 |
| Soham Removal & Clearance Co Ltd | Transport & logistics | 2026 |
| Soho Iconic Limited | Wholesale & retail | 2020 |
| Soil Services Limited | Extraterritorial | 1989 |
| Solas Music Limited | Information & communication | 2018 |
| Solomon Management Ltd | Real estate | 2022 |
| Somerset Hideaways Limited | Professional & scientific | 1994 |
| Somerville Lodge Limited | Professional & scientific | 2008 |
| Sorillas Homes Ltd | Financial services | 2017 |
| Sosure Music Recordings Ltd | Information & communication | 2013 |
| Southfield Trading (UK) Limited | Professional & scientific | 1953 |
| Southfields Stables Limited | Arts & recreation | 2006 |
| Southgate of Newmarket Limited | Other services | 2009 |
| Southoe Consultancy Ltd. | Professional & scientific | 2010 |
| SP Suites Limited | Real estate | 2019 |
| Spark Home Education Limited | Information & communication | 2024 |
| SPH Sidhu Ltd | Wholesale & retail | 2023 |
| SPI20SPV001 Limited | Real estate | 2019 |
| Spire Mechanical Services Ltd | Construction | 2019 |
| Spoonline Ltd | Real estate | 2025 |
| Sporting 87 Football Club Limited | Arts & recreation | 2017 |
| Sports Days Ltd | Administrative & support | 1997 |
| Squash Court Flats Management Co Ltd | Real estate | 2011 |
| SRC Heating and Plumbing Limited | Construction | 2017 |
| SS and B Brickworks Ltd | Construction | 2018 |
| SSJ Property Developers Ltd | Construction | 2025 |
| ST Christopher's Robins Childcare Services Limited | Education | 2014 |
| ST Clements 2023 Ltd | Real estate | 2023 |
| ST Neots Barbers Ltd | Other services | 2018 |
| Standsure Consultancy Ltd | Professional & scientific | 2024 |
| Stanli Limited | Health & social care | 2021 |
| Stardust Records Ltd | Arts & recreation | 2025 |
| Stargrove Trading Limited | Administrative & support | 1992 |
| Stately Holiday Cottages Limited | Professional & scientific | 1987 |
| Station Road Developments (Histon) Ltd | Construction | 2023 |
| Steadfast Security Services Ltd | Administrative & support | 2025 |
| Stealthmode Growth Partners Ltd | Administrative & support | 2025 |
| Stella Furniture Ltd | Wholesale & retail | 2024 |
| Steph's Therapy Ltd | Other services | 2026 |
| Sterling Artificial Intelligence Ltd | Information & communication | 2025 |
| Sterling Hospitality Ltd | Hospitality | 2024 |
| Stetchworth Park Competition Limited | Agriculture & fishing | 2020 |
| Stetchworth Park Stud Limited | Extraterritorial | 2013 |