| Stephen Peto Limited | Information & communication | 1997 |
| Stephens & Co Group (UK) Ltd | Financial services | 2024 |
| Sterling Accounting and Business Services Limited | Professional & scientific | 2006 |
| Sterling Lifting Services Ltd | Construction | 2020 |
| Sterling Plant Movement Services Ltd | Construction | 2022 |
| Sterling Plumbing and Heating Services Limited | Construction | 2026 |
| Steve Charlton Training Services Ltd | Education | 2024 |
| Steve Clark Music Limited | Arts & recreation | 2025 |
| Steve Davis Developments Limited | Construction | 2002 |
| Steve Grantham Bespoke Estate Agent Limited | Real estate | 2021 |
| Steve Kilford Ltd | Construction | 2024 |
| Steve Lovell Associates Limited | Administrative & support | 1991 |
| Steve Reid Brickwork Ltd | Construction | 2014 |
| Steve Silvester Services Ltd | Construction | 2019 |
| Steven Afshar Limited | Extraterritorial | 2022 |
| Sticker Wizard Ltd | Manufacturing | 2020 |
| Stickhead Aquatics Ltd | Agriculture & fishing | 2025 |
| Stickyair Limited | Information & communication | 2009 |
| Still Alice Limited | Information & communication | 2011 |
| Stirrup Safety Consulting Limited | Professional & scientific | 2024 |
| STK Interiors Limited | Construction | 2021 |
| Stmj Group Limited | Health & social care | 2017 |
| Stocklands Aviation Services Limited | Professional & scientific | 2013 |
| Stocklands Construction Limited | Construction | 2024 |
| Stonecrest Housing Limited | Real estate | 2024 |
| Stonefen Limited | Professional & scientific | 2026 |
| Stoneley Scaffolding Limited | Construction | 2022 |
| Stoneman Mews Management Company Limited | Professional & scientific | 2014 |
| Stoneridge Estates Ltd | Real estate | 2023 |
| Stonetech Solutions Ltd | Information & communication | 2026 |
| Stonewalled LLP | | 2016 |
| Storm Air Conditioning Limited | Construction | 2021 |
| Storm Athletics UK | Arts & recreation | 2022 |
| Storm Partnership Ltd | Construction | 2024 |
| Storm Trading UK Ltd | Wholesale & retail | 2023 |
| Stourmint Ltd | Hospitality | 2026 |
| STR8 Services UK Limited | Education | 2024 |
| Stratalink Ltd | Professional & scientific | 2024 |
| Strategic Consultancy Support Services Ltd | Professional & scientific | 2022 |
| Stratfield Park M.C. Limited | Real estate | 1988 |
| Straticas Limited | Professional & scientific | 2024 |
| Strattiss Ltd | Manufacturing | 2026 |
| Streamline PR Limited | Administrative & support | 2015 |
| Streamside Farms Ltd | Agriculture & fishing | 2018 |
| Street Harvest Limited | Hospitality | 2021 |
| Strength Cards Ltd | Manufacturing | 2018 |
| Stretcher Brickwork Limited | Construction | 2003 |
| Stribling Ltd | Real estate | 2024 |
| Strides ARC Ltd | Wholesale & retail | 2021 |
| Stridex Health Ltd | Health & social care | 2025 |
| Strike 3 Limited | Information & communication | 2014 |
| Strong Island Solutions Limited | Wholesale & retail | 2024 |
| Strongfort Noveason Ltd | Administrative & support | 2023 |
| Strontian Gases Limited | Manufacturing | 2026 |
| Strontian Group Limited | Construction | 2020 |
| Strontian Holdings Limited | Financial services | 2026 |
| Structures and Covers Limited | Administrative & support | 2005 |
| Strutton Ground Holdings Limited | Financial services | 2024 |
| Strutton Ground Limited | Real estate | 2024 |
| STU4RT Limited | Construction | 2019 |
| Stuart Lodge HW Ltd | Real estate | 2021 |
| Stuart Quality Limited | Professional & scientific | 2022 |
| Studio H Limited | Other services | 2023 |
| Studio HW Ltd | Professional & scientific | 2019 |
| Studio Lundi Limited | Professional & scientific | 2012 |
| Studio Nimic Limited | Professional & scientific | 2022 |
| Studio Products Ltd | Manufacturing | 2023 |
| Studio Sattva Ltd | Arts & recreation | 2025 |
| Studio Sturt Limited | Professional & scientific | 2025 |
| STUDIO22 Grooming Ltd | Other services | 2023 |
| Stump Master Tree Services Ltd | Agriculture & fishing | 2022 |
| Stuphie Ltd | Manufacturing | 2019 |
| STX Technology Ltd | Wholesale & retail | 2024 |
| Style by Kate Lauren Ltd | Administrative & support | 2026 |
| Stylish Glass Limited | Manufacturing | 2014 |
| SU Fish Bar Ltd | Hospitality | 2021 |
| Submarine Cable Solutions LLP | | 2014 |
| Subtari Limited | Wholesale & retail | 2024 |
| Success Services Ltd | Health & social care | 2025 |
| SUE Generis Consultants Ltd | Professional & scientific | 2025 |
| Sugden Services Limited | Construction | 2018 |
| Summerley Recruitment Ltd | Administrative & support | 2020 |
| Summers and Co Hair Boutique Limited | Other services | 2020 |
| Summers P Improvements Ltd | Construction | 2026 |
| Summers Properties & Lettings Ltd | Real estate | 2020 |
| Summers Property Improvements Limited | Construction | 2025 |
| Summersdale Plastering Limited | Construction | 2016 |
| Summit Engineering Consultancy Ltd | Professional & scientific | 2024 |
| Summit Haus Ltd | Construction | 2024 |
| Summit Protection Ltd | Financial services | 2025 |
| Summit Safety Solutions Limited | Professional & scientific | 2016 |
| Sumrepute Limited | Professional & scientific | 2020 |
| Sunday's Coffee Limited | Hospitality | 2025 |
| Sunny Airport Cars Limited | Transport & logistics | 2016 |
| Sunset Beach Retreats Ltd | Real estate | 2025 |
| Sunshine Day Centre Limited | Health & social care | 2010 |
| Super Desk Supplier Ltd | Other services | 2025 |
| Super Energy Ltd | Wholesale & retail | 2021 |
| Super Trap Ltd | Manufacturing | 2025 |
| Super Yacht Networking & Cybersecurity Ltd | Information & communication | 2024 |