| S E Welch Limited | Professional & scientific | 2015 |
| S G Squared Limited | Real estate | 2019 |
| S K London Property Limited | Real estate | 2019 |
| S N J Leisure Limited | Administrative & support | 2008 |
| S N Refurbishment Limited | Construction | 2015 |
| S Oreilly Consulting Limited | Real estate | 2024 |
| S P Insight Solutions Ltd | Wholesale & retail | 2022 |
| S&E Care Ltd | Health & social care | 2021 |
| S&S IT Consultants Limited | Information & communication | 2016 |
| S&S Rani’S Kitchen Ltd | Wholesale & retail | 2025 |
| S&Sf Limited | Hospitality | 2024 |
| S&T Fire Ltd | Public administration | 2024 |
| S'Take Away Limited | Hospitality | 2025 |
| S-Profit Ltd. | Wholesale & retail | 2011 |
| S.A.Used Cars Limited | Wholesale & retail | 2025 |
| S.C Windows & Construction Limited | Construction | 2022 |
| S.G.B. Property Services Limited | Real estate | 2026 |
| S.K. Construction (UK) Ltd | Construction | 2013 |
| S.L.N. Homes Ltd | Real estate | 2023 |
| S.L.N. Medics Ltd. | Health & social care | 2009 |
| S19 Sporting Services Ltd | Wholesale & retail | 2025 |
| S3 Management Ltd | Information & communication | 2022 |
| S3 Soft Ltd | Administrative & support | 2010 |
| S8 Marketing Ltd | Information & communication | 2019 |
| S@I Pest Control Ltd | Administrative & support | 2016 |
| SA & JO Care Limited | Health & social care | 2011 |
| Sab-Engineering Ltd | Professional & scientific | 2024 |
| Sabah Properties Ltd | Real estate | 2023 |
| Saber Security Systems Limited | Administrative & support | 2021 |
| Sabh Business Solutions Ltd | Information & communication | 2019 |
| Saeef Pharma Limited | Wholesale & retail | 2022 |
| Safe Space for YOU CIC | Administrative & support | 2025 |
| Safecrowds HVM Barriers Ltd | Administrative & support | 2023 |
| Safeguard Academy Ltd | Education | 2022 |
| Safesure UK Ltd | Construction | 2024 |
| Safeway Homes Ltd | Real estate | 2018 |
| Sagnus Ltd | Other services | 2020 |
| Sago Fmcg Limited | Wholesale & retail | 2024 |
| Sagoo Estates Limited | Real estate | 2024 |
| SAH and Mahto Ltd | Health & social care | 2019 |
| Sahara Evolution Decor Ltd | Other services | 2019 |
| Saidarshan Distribution Ltd | Wholesale & retail | 2019 |
| Sainan Limited | Wholesale & retail | 1997 |
| Saint Francis Dementia Care Service Limited | Health & social care | 2026 |
| Saint George Vision & Investment Ltd | Construction | 2025 |
| Sairam Distribution Ltd | Wholesale & retail | 2025 |
| Saiuk Ltd | Wholesale & retail | 2023 |
| Saizeel Limited | Wholesale & retail | 2023 |
| Sajha UK Limited | Construction | 2018 |
| Sakc Ltd | Health & social care | 2018 |
| Sales Unlocked Ltd | Manufacturing | 2026 |
| Salient Discovery Limited | Administrative & support | 2018 |
| Salisbury House London Limited | Health & social care | 2025 |
| Saltridge UK Limited | Professional & scientific | 2014 |
| Salus Assistance Ltd | Professional & scientific | 2025 |
| SAM Catering Hornchurch Limited | Hospitality | 2025 |
| SAM Consultancy and Services Ltd | Information & communication | 2023 |
| SAM DON Music Limited | Professional & scientific | 2016 |
| SAM Stop Limited | Education | 2023 |
| Sama UK Trading Ltd | Wholesale & retail | 2024 |
| Samarnic Ltd | Financial services | 2018 |
| Samarry Ltd | Construction | 2026 |
| Samarth Stores Ltd | Wholesale & retail | 2025 |
| Same Medical Ltd | Health & social care | 2026 |
| Samiul Ahmed Ltd | Manufacturing | 2022 |
| Samosi Ltd | Hospitality | 2026 |
| Sampri & Co Limited | Professional & scientific | 2022 |
| Samreet Kaurs Ltd | Real estate | 2022 |
| Sams Homes Limited | Construction | 2016 |
| Samuel Rose Developments Limited | Real estate | 2025 |
| Samuels Media Limited | Administrative & support | 2011 |
| Sanca's Care Ltd | Health & social care | 2025 |
| Sand Hues Ltd | Manufacturing | 2022 |
| Sandal Beauty Saloon Ltd | Other services | 2023 |
| Sandhu Capital Holdings Limited | Real estate | 2024 |
| Sandhurst Drive Limited | Real estate | 2018 |
| Sandjack Investments Limited | Extraterritorial | 2007 |
| Sangar Security Systems Ltd | Administrative & support | 2013 |
| Sansum Interiors Limited | Construction | 2008 |
| Santarra Limited | Administrative & support | 2025 |
| Santos Geoconsulting Ltd | Professional & scientific | 2025 |
| Sanus Shield Ltd | Financial services | 2025 |
| Sanvish Limited | Health & social care | 2022 |
| Sanvish Properties Ltd | Real estate | 2025 |
| Sapore Divino Ltd | Hospitality | 2025 |
| Sapphire Group (GB) Limited | Other services | 2006 |
| Sapphire Property Solutions (GB) Ltd | Other services | 2004 |
| SAR LA Thai Ltd | Hospitality | 2023 |
| Sara Coopers Accountants Ltd | Professional & scientific | 2016 |
| Sara Coopers Consulting Ltd | Professional & scientific | 2019 |
| Sarah Ameen Consulting Ltd | Information & communication | 2020 |
| Sarah L. Robinson Limited | Health & social care | 2010 |
| Sarah Mills Occupational Therapy and Coaching Ltd | Health & social care | 2025 |
| Sarah Morris Limited | Health & social care | 2021 |
| Sarbsons Limited | Construction | 2015 |
| Sarso Limited | Professional & scientific | 2011 |
| Sarsvip Limited | Real estate | 2026 |
| Sartie Electrical Services Ltd | Construction | 2024 |
| Sarva Massage & Wellness Ltd | Other services | 2018 |
| Sarw Properties Ltd | Real estate | 2018 |