| Sacred Hawk Limited | Wholesale & retail | 2020 |
| Saddle and Style Interiors Ltd | Wholesale & retail | 2025 |
| Safe and Sound GAS Services Limited | Construction | 2004 |
| Safe Nomad Limited | Wholesale & retail | 2019 |
| Safe on SET Limited | Other services | 2021 |
| Safeoaks Lifting Limited | Construction | 2017 |
| Safetopia CIC | Other services | 2024 |
| SAG Hospitality Ltd | Hospitality | 2025 |
| SAI Siri Ltd | Real estate | 2026 |
| Saif Resolve Limited | Extraterritorial | 2009 |
| Saint Albans Sash Limited | Construction | 2016 |
| Saint Pierre School Ltd | Education | 2008 |
| Saisantoshi Infotech Limited | Information & communication | 2011 |
| Saitch Services Limited | Manufacturing | 2013 |
| Saku Productions Ltd | Information & communication | 2021 |
| Salad LAB Ltd | Hospitality | 2024 |
| Salcette Remodelling Company Limited | Real estate | 2024 |
| Salix Moon Apothecary Ltd | Manufacturing | 2018 |
| Salmons Farm (Essex) Ltd | Construction | 2025 |
| Salsa Chillout Limited | Other services | 2022 |
| Salsa Restaurant Limited | Hospitality | 2009 |
| Salter Building Services Limited | Construction | 2024 |
| Salter Property Ltd | Real estate | 2022 |
| Saltwater Beach Cafe Limited | Hospitality | 2017 |
| SAM Cleaning Services Group Limited | Administrative & support | 2024 |
| Samantha Collison Coaching Ltd | Other services | 2024 |
| Samuda Property Investment Ltd | Real estate | 2023 |
| Sandhu Investments Limited | Real estate | 2002 |
| Sandhu Medicals Limited | Health & social care | 2019 |
| Sandhurst (Newhomes) Limited | Administrative & support | 2002 |
| Sandhurst Contracts Limited | Construction | 2007 |
| Sandmoore Capital Ltd | Real estate | 2014 |
| Sandmoore Consultants Ltd | Real estate | 2018 |
| Sandstark Consultants Ltd | Professional & scientific | 2019 |
| Sandstone Court (Merstham) Management Company Limited | Households | 2021 |
| Sanitopia CIC | Other services | 2025 |
| Sapores Camden Limited | Hospitality | 2016 |
| Sapphire Packaging Ltd | Wholesale & retail | 2014 |
| Sapphire Site Services Ltd | Construction | 2014 |
| Sara's Tea Garden Limited | Hospitality | 2012 |
| Sarafin Partners Limited | Administrative & support | 2024 |
| Sarah Clark AAC Limited | Education | 2022 |
| Sarah Tucker Management Limited | Financial services | 2025 |
| SAS Introductory Services Limited | Professional & scientific | 2023 |
| Sascon Limited | Information & communication | 2004 |
| Sasha Alexander Photography Ltd | Professional & scientific | 2018 |
| Satis Associates Limited | Information & communication | 2017 |
| Sauf Pompiers Limited | Information & communication | 2013 |
| Savannah Apps Ltd | Information & communication | 2026 |
| Savannah Heights Management Company Limited | Professional & scientific | 2023 |
| Saxon House (Benfleet) Management Company Ltd | Households | 2021 |
| Sayadocs Ltd | Health & social care | 2021 |
| SB Care Consultants Limited | Other services | 2025 |
| SB Electrical Services (Essex) Limited | Construction | 2024 |
| SB Storage Limited | Extraterritorial | 2022 |
| Sbeve Entertainment Ltd | Professional & scientific | 2023 |
| SBX Innovation Ltd | Information & communication | 2023 |
| SC Actuarial Services Limited | Administrative & support | 2014 |
| SC Design & Build Ltd. | Professional & scientific | 2014 |
| SC Maintenance Solutions Ltd | Construction | 2020 |
| Scalemygames Limited | Information & communication | 2024 |
| Scalp Nation Ltd | Other services | 2019 |
| Scalp Supplies Ltd | Other services | 2022 |
| Scape Interiors Limited | Wholesale & retail | 2007 |
| Scar Fashion Ltd | Professional & scientific | 2003 |
| Scarlett-Ray Consultants Limited | Professional & scientific | 2013 |
| Schnitzel Records Limited | Information & communication | 2006 |
| Scholfield Rail and Construction Limited | Construction | 2007 |
| School Impact Solutions Ltd | Information & communication | 2022 |
| SCK Holdings Limited | Financial services | 2017 |
| Scorpion ES Ltd | Construction | 2013 |
| Scott D Property Management Limited | Real estate | 2019 |
| Scrambled Limited | Information & communication | 2015 |
| Scrap My Vehicle North East Limited | Wholesale & retail | 2023 |
| SCULPT3D Ltd | Arts & recreation | 2023 |
| SCW Psychology Ltd | Education | 2023 |
| Scwiar Capital Ltd | Professional & scientific | 2014 |
| Scwiar Investments Ltd | Professional & scientific | 2015 |
| SDE Electrical Contractors Limited | Construction | 2007 |
| Sdjh Consulting Ltd | Professional & scientific | 2026 |
| SDM Care Homes Ltd | Health & social care | 2024 |
| SDM Care Solutions Limited | Health & social care | 2023 |
| Sdmh Limited | Wholesale & retail | 2025 |
| SE Maintenance Contractors Ltd | Construction | 2024 |
| Seacraft Ltd | Extraterritorial | 2022 |
| Sealed Bros Ltd | Construction | 2026 |
| Seals Property Limited | Real estate | 2022 |
| Sean Calvert Sports Limited | Information & communication | 2019 |
| Sean Scanlan Electrical Services Ltd | Construction | 2019 |
| Searayell Construction & Fabrication Ltd | Construction | 2010 |
| Seareach PLC | Information & communication | 2009 |
| Seareach Property Ltd | Real estate | 2021 |
| Searle Insulation Services Ltd | Construction | 2025 |
| Seaside Soul Ltd | Arts & recreation | 2019 |
| Seasouth Mining and Quarrying Ltd | Mining & quarrying | 2024 |
| Sebmm Limited | Wholesale & retail | 2023 |
| Seco Solutions Limited | Administrative & support | 2013 |
| Section 8 Productions Ltd | Information & communication | 2011 |
| Sectorum Ltd | Financial services | 2015 |
| Secure & Store (Essex) Limited | Transport & logistics | 2019 |