| ST Andrews Court RTM Company Limited | Households | 2022 |
| ST Ann's Quay Management Limited | Real estate | 2001 |
| ST Ann's Residential Limited | Real estate | 2020 |
| ST Annes Convent Residents Association Durham Limited | Real estate | 2010 |
| ST Anton Ltd | Real estate | 2025 |
| ST Cuthbert Newcastle Estates (Residential) Limited | Real estate | 2021 |
| ST Cuthbert's Care | Health & social care | 1982 |
| ST Design Services Ltd | Professional & scientific | 2023 |
| ST Ebba Capital Limited | Financial services | 2009 |
| ST Ebba Restoration Limited | Administrative & support | 2010 |
| ST Edmunds Manor (Sedgefield) Management Company Limited | Real estate | 2017 |
| ST Electrical Contractors (NE) Limited | Construction | 2017 |
| ST George's Mews (Jesmond) Management Limited | Real estate | 2002 |
| ST George's Pre-School Ltd | Education | 2009 |
| ST James Bark Ltd | Other services | 2021 |
| ST James Boulevard Developments Ltd | Construction | 2017 |
| ST James Developers Limited | Construction | 2017 |
| ST James Partners Limited | Real estate | 2016 |
| ST James Student Investments Limited | Households | 2019 |
| ST James' Central 7 Limited | Construction | 2020 |
| ST James' Central 9 Limited | Construction | 2026 |
| ST James' Central Investments Limited | Construction | 2015 |
| ST James' Cross Limited | Construction | 2019 |
| ST John Street Property Management Company | Hospitality | 2012 |
| ST John's Place (Alnwick) Management Company Limited | Real estate | 2018 |
| ST Lukes Mews (Durham) Management Company Limited | Real estate | 2014 |
| ST Mary's Place, Church Fenton Limited | Households | 2020 |
| ST Mary's Stannington Management Company Limited | Households | 2007 |
| ST Michael's (Clifton Road) Limited | Real estate | 2004 |
| ST Trinity Limited | Real estate | 2009 |
| ST Wilfrid View (Ripon) Management Company Limited | Real estate | 2019 |
| ST. Anthony of Padua Community Association | Hospitality | 1986 |
| ST. Anthony's News Ltd | Wholesale & retail | 2020 |
| ST. Anthony's Youth Education and Support | Health & social care | 2009 |
| ST. Catherines Court (Sandyford) Limited | Real estate | 2006 |
| ST. Cuthbert Newcastle Estates Limited | Real estate | 1928 |
| ST. Keverne Square Management Company Limited | Real estate | 2000 |
| ST. Martin's Centre Partnership | Hospitality | 2004 |
| ST. Mary's Mews (Whitley Bay) Management Company Limited | Real estate | 1992 |
| ST. Oswald's Hospice Limited | Health & social care | 1974 |
| ST. Oswald's Hospice Promotions Limited | Arts & recreation | 1996 |
| ST. Wilfrid's Court (Hexham) Limited | Households | 1988 |
| St.Julian's Estate Limited(The) | Real estate | 1905 |
| Stable Park Square Management Company Limited | Households | 2026 |
| Stable State Consulting Ltd | Information & communication | 2024 |
| Stace Construction Services Ltd | Construction | 2025 |
| Stack (Bishop Auckland) Limited | Hospitality | 2022 |
| Stack (Durham) Limited | Hospitality | 2022 |
| Stack (Leeds) Limited | Hospitality | 2024 |
| Stack (Lincoln) Limited | Hospitality | 2021 |
| Stack (Manchester) Limited | Hospitality | 2023 |
| Stack (Middlesbrough) Limited | Hospitality | 2021 |
| Stack (Northampton) Limited | Hospitality | 2022 |
| Stack (Seaburn) Limited | Hospitality | 2019 |
| Stack (Sheff'D) Limited | Hospitality | 2022 |
| Stack (Whitley Bay) Limited | Hospitality | 2022 |
| Stack (Wigan) Limited | Hospitality | 2023 |
| Stack Bidco Limited | Financial services | 2023 |
| Stack Containers Limited | Hospitality | 2016 |
| Stack Dynamic Web Services Ltd | Information & communication | 2019 |
| Stack Group Limited | Professional & scientific | 2019 |
| Stack Midco Limited | Financial services | 2023 |
| Stack Solutions NE Ltd | Information & communication | 2020 |
| Stack Topco Limited | Financial services | 2023 |
| Stack Trading Limited | Hospitality | 2018 |
| Stacked UK Collective Ltd | Wholesale & retail | 2025 |
| Staddle Five Limited | Real estate | 2023 |
| Staddle Four Limited | Real estate | 2023 |
| Staddle One Limited | Real estate | 2023 |
| Staddle Properties Ltd | Real estate | 2021 |
| Staddle SIX Limited | Real estate | 2023 |
| Staddle Three Limited | Real estate | 2023 |
| Staddle Two Limited | Real estate | 2023 |
| Staddlestone Group Limited | Financial services | 2025 |
| Stadium Export Services Limited | Manufacturing | 1995 |
| Staffordshire Distillery Ltd | Manufacturing | 2018 |
| Stage Door Events Ltd | Arts & recreation | 2022 |
| Stage SIX Limited | Professional & scientific | 2020 |
| STAGE2STAGE Productions Limited | Arts & recreation | 2020 |
| Stagg Contractors Ltd | Construction | 2025 |
| STAGNO.56 Ltd | Wholesale & retail | 2025 |
| Stait Cameras Limited | Professional & scientific | 2005 |
| Staithes Garage Limited | Wholesale & retail | 2002 |
| Staithes Lane Management Limited | Real estate | 1998 |
| Staiths (Phase 2) Management Company Limited | Real estate | 2004 |
| Staiths Management Company Limited | Households | 2002 |
| Stalwart Properties Limited | Real estate | 2016 |
| Stan Dawson Limited | Transport & logistics | 1981 |
| Standard Indian Takeaway Ltd | Hospitality | 2018 |
| Standby Group Ltd | Financial services | 2016 |
| Standby Healthcare (Midlands) Ltd | Administrative & support | 2022 |
| Standby Healthcare (North West) Ltd | Administrative & support | 2022 |
| Standerwick & Stott Ltd | Other services | 2020 |
| Standout National Relocations Limited | Hospitality | 2024 |
| Stanfam Properties Limited | Real estate | 2001 |
| Stanghal Computing Limited | Manufacturing | 1995 |
| Stanhope Desserts Limited | Hospitality | 2025 |
| Stanislas Asher Logistics Ltd | Transport & logistics | 2025 |
| Stanley Oliver Limited | Education | 2017 |
| Stanley Property Services (SPS) Ltd | Real estate | 2024 |