| Sell With Jane Limited | Real estate | 2024 |
| Selling Hub Ltd | Wholesale & retail | 2025 |
| Selluxry Ltd | Wholesale & retail | 2026 |
| Semicon Laser Ltd. | Manufacturing | 2026 |
| Send Pathways Ltd | Education | 2022 |
| Senesthetics Limited | Health & social care | 2017 |
| Sensible Events Limited | Arts & recreation | 2012 |
| Sensound Ltd | Manufacturing | 2022 |
| Sentimentalist TOO Limited | Information & communication | 2024 |
| Sentinel 68 Ltd | Professional & scientific | 2022 |
| Sentry Security Solutions Limited | Wholesale & retail | 2025 |
| Sequential Accounts Limited | Professional & scientific | 2019 |
| Ser-Tec Systems (Midlands) Limited | Construction | 1994 |
| Ser-Tec Systems Limited | Professional & scientific | 1986 |
| Servintegra Limited | Administrative & support | 2018 |
| Seventy Four Energy Holdings Limited | Financial services | 2024 |
| Severn Surveyors Ltd | Professional & scientific | 2025 |
| SFG Property 2 LLP | | 2016 |
| SFG Property LLP | | 2013 |
| SG Brahma Properties Ltd | Real estate | 2026 |
| SG PA Hospitality Solutions Limited | Hospitality | 2012 |
| SGJ Property Limited | Real estate | 2022 |
| SGP Mortgages Limited | Financial services | 2022 |
| SH Laser Cutting & Fabrications Limited | Manufacturing | 2024 |
| Shadrake Services Ltd | Real estate | 2023 |
| Shafik Khalaf Services Limited | Health & social care | 2019 |
| Shageodh Ltd | Real estate | 2021 |
| Shahjahani Pictures Limited | Information & communication | 2021 |
| Shaped by Lucy Ltd | Arts & recreation | 2024 |
| Shapeshifter Performance (Sports) Ltd | Arts & recreation | 2024 |
| Sharepoint Stuff Ltd | Information & communication | 2022 |
| Shaukatarfan Ltd | Wholesale & retail | 2022 |
| Shaun Lycett Racing Ltd | Arts & recreation | 2016 |
| Sheedy Limited | Information & communication | 2019 |
| Sheldon Property Management Limited | Real estate | 2014 |
| Shella Palace Ltd | Wholesale & retail | 2025 |
| Shellard Anaesthetic Services Ltd | Health & social care | 2019 |
| Shepley Property Group Ltd | Real estate | 2024 |
| Sherbet Donkey Media Limited | Other services | 2019 |
| Sherwood Harborne Limited | Professional & scientific | 1995 |
| Shield 'N' Shine Limited | Wholesale & retail | 2017 |
| Shire Cars Stourbridge Ltd | Wholesale & retail | 2016 |
| Shire Consulting Limited | Professional & scientific | 1989 |
| Shire Mortgages Limited | Financial services | 2018 |
| Shire Property Ltd | Real estate | 2021 |
| Shire Structures Limited | Construction | 1998 |
| Shire UK Holdco Limited | Financial services | 2025 |
| Shiv Private Ltd | Wholesale & retail | 2025 |
| Shiva Financial Services Limited | Professional & scientific | 2019 |
| Sholfins Swim School CIC | Education | 2019 |
| Show OFF Home Improvements Ltd | Manufacturing | 2025 |
| Shri Estates Ltd | Real estate | 2023 |
| Shuker Cars Ltd | Wholesale & retail | 2013 |
| Shukla Medical Europe Ltd | Financial services | 2019 |
| Shukla Medical International Ltd | Wholesale & retail | 2020 |
| Shukla Medical UK Ltd | Financial services | 2019 |
| Sibson Alif Limited | Wholesale & retail | 2026 |
| Sidemoor Fishbar Mobile Limited | Hospitality | 2021 |
| Sidrar Trading Ltd | Wholesale & retail | 2025 |
| Siennia Ltd | Real estate | 2026 |
| Sifco Applied Surface Concepts (UK) Limited | Manufacturing | 1988 |
| Sigma Capital Assets Ltd | Other services | 2016 |
| Signature Properties and Residential Limited | Real estate | 2024 |
| Sikandar Enterprises Trading Ltd | Wholesale & retail | 2025 |
| Silent Beats Limited | Information & communication | 2014 |
| Silk Films Limited | Administrative & support | 2007 |
| Silver Birch Steel Ltd | Other services | 2024 |
| Silverback Gym Wear Ltd | Administrative & support | 2016 |
| Simcra Construction Limited | Construction | 1996 |
| Simply PL4NT Hire Ltd | Administrative & support | 2025 |
| Simpson Smiles Ltd | Health & social care | 2024 |
| Simrage Ltd | Wholesale & retail | 2024 |
| Simrajsar Limited | Financial services | 2013 |
| Simtar Holdings Limited | Financial services | 2020 |
| Sinclair Taylor Management Services Ltd | Administrative & support | 2009 |
| Single Point Project Management Limited | Administrative & support | 2001 |
| Sinoper Consulting Limited | Professional & scientific | 2022 |
| SIP and Slice Limited | Hospitality | 2026 |
| Sirius Asset Solutions Ltd | Administrative & support | 2017 |
| Sirona Healthcare Limited | Health & social care | 2020 |
| SIS Systems (UK) Limited | Manufacturing | 1996 |
| Sisson Holdings Ltd | Financial services | 2023 |
| Sitam Limited | Financial services | 2014 |
| Site Smart Solutions Ltd | Information & communication | 2023 |
| Sixsiblings Ltd | Wholesale & retail | 2023 |
| Sixty SIX Media Limited | Information & communication | 2020 |
| SJ Butler Limited | Construction | 2016 |
| SJC Accountancy Services Limited | Professional & scientific | 2020 |
| SJD Architects & Developments Ltd | Construction | 2013 |
| SJS Maintenance 2025 Limited | Administrative & support | 2025 |
| SK Propertyco Ltd | Real estate | 2021 |
| Skagen Limited | Financial services | 2019 |
| Skanair Technologies Limited | Wholesale & retail | 2005 |
| Skin and Hair Ltd | Other services | 2022 |
| Skinfolk Ltd | Other services | 2024 |
| Skulpt by Sarah Ltd | Other services | 2025 |
| Skunk Partners Ltd | Information & communication | 2016 |
| Skyline Hospitals Ltd | Health & social care | 2023 |
| Skyrocket Partnerships Limited | Professional & scientific | 2017 |
| Slap 8 Limited | Professional & scientific | 2008 |