| S & D Joinery Limited | Manufacturing | 2023 |
| S & E Consulting Limited | Real estate | 2017 |
| S & M Propertys Ltd | Real estate | 2008 |
| S E D Electrical Limited | Construction | 2006 |
| S K Sish Grill Limited | Hospitality | 2025 |
| S N Healthcare Ltd | Health & social care | 2017 |
| S Patel Property Investment Limited | Real estate | 2021 |
| S W Metal Trading Ltd | Administrative & support | 2015 |
| S W Property Investments Limited | Real estate | 2018 |
| S Wallace Consultancy Ltd | Professional & scientific | 2025 |
| S&D London Builders Ltd | Construction | 2024 |
| S&G HR Solutions Ltd | Administrative & support | 2015 |
| S&H Developments Limited | Construction | 2011 |
| S&I Ventures Ltd | Real estate | 2008 |
| S&M Electrical EOT Limited | Administrative & support | 2023 |
| S&M Electrical Limited | Construction | 1987 |
| S&R Plumbing Limited | Construction | 2026 |
| S&S Collective Limited | Administrative & support | 2025 |
| S&S Online Ltd | Wholesale & retail | 2016 |
| S-Physiotherapy Limited | Health & social care | 2017 |
| S.L.L. Limited | Real estate | 2000 |
| S.S. Decorators Limited | Construction | 2009 |
| S29 Ltd | Administrative & support | 2024 |
| S2SCPC Holdings Limited | Real estate | 2024 |
| S4RR Properties Ltd | Real estate | 2016 |
| Saammi Ltd | Health & social care | 2023 |
| Saansoft Solutions Limited | Information & communication | 2014 |
| Saanvi Process Engineers & Consultants Ltd | Information & communication | 2007 |
| Saapos Ltd | Manufacturing | 2011 |
| Saara Real Estate Limited | Real estate | 2020 |
| Saas Estates Ltd | Real estate | 2022 |
| Sabat Investments Ltd | Households | 2024 |
| Sabba Carpets and Furniture UK Limited | Wholesale & retail | 2024 |
| Sabba Services Ltd | Administrative & support | 2019 |
| Sabr Remedies Ltd | Wholesale & retail | 2021 |
| Sachaé Rituals Ltd | Wholesale & retail | 2025 |
| Sackville Rogers Limited | Real estate | 2006 |
| Sada Builders Ltd | Manufacturing | 2019 |
| Sadie Investments Limited | Real estate | 2018 |
| Safal Limited | Wholesale & retail | 2024 |
| Safaricom Limited | Administrative & support | 2003 |
| Safe Hand Surgeon Limited | Health & social care | 2019 |
| Safeguarding Circle LLP | | 2022 |
| Safesite Solutions Limited | Professional & scientific | 2023 |
| Safintlon Limited | Construction | 1997 |
| Safne Limited | Professional & scientific | 2016 |
| Sage 3 Ltd | Professional & scientific | 2026 |
| Sage Femme Ltd | Health & social care | 2006 |
| Sageata Ltd | Construction | 2022 |
| Sahajanand Limited | Hospitality | 2024 |
| Sahara Lounge Ltd | Hospitality | 2009 |
| SAI Property Management Ltd | Real estate | 2020 |
| SAI MAA Consulting Limited | Professional & scientific | 2014 |
| Saiber-Security Limited | Information & communication | 2024 |
| Sailee Limited | Real estate | 2017 |
| Saim Construction Limited | Manufacturing | 2021 |
| Saint Felix School Limited | Education | 2021 |
| Saish Infotech Ltd | Information & communication | 2010 |
| Saiwil Limited | Information & communication | 2006 |
| Sajn Limited | Hospitality | 2018 |
| Sak.G Limited | Financial services | 2019 |
| Sak.G Trade Limited | Wholesale & retail | 2024 |
| Sakifa Ltd | Financial services | 2026 |
| SAL Consultancy Ltd | Health & social care | 2019 |
| SAL London Limited | Professional & scientific | 2014 |
| Salaam Beverages Co Limited | Wholesale & retail | 2016 |
| Salaam Health Ltd. | Wholesale & retail | 2018 |
| Salata & Associates Limited | Other services | 1996 |
| Salik Limited | Administrative & support | 2009 |
| Salon Hygiene Solutions Limited | Manufacturing | 2017 |
| SAM Interiors Ltd | Construction | 2018 |
| SAM Joseph Studios Ltd | Arts & recreation | 2026 |
| Samantha Brownstein Design Limited | Information & communication | 2017 |
| Samarth Events and Creations Limited | Hospitality | 2023 |
| Samco Plumbing Limited | Construction | 2025 |
| Samcron Ltd | Real estate | 2021 |
| Samdan Productions Limited | Administrative & support | 2025 |
| Samdev Contractors Limited | Construction | 2004 |
| Samdroid Ltd | Information & communication | 2016 |
| Sammy Labs Ltd | Information & communication | 2024 |
| Samos Group Ltd | Construction | 2018 |
| Samsaad Accounting Limited | Professional & scientific | 2019 |
| Samuel Chase Limited | Administrative & support | 2025 |
| Samvicks Haulage Limited | | 1988 |
| Samz Ltd | Hospitality | 2017 |
| Samz Services Ltd | Wholesale & retail | 2024 |
| SAN Accounting Services Ltd | Professional & scientific | 2014 |
| SAN Carpentry Ltd | Construction | 2021 |
| SAN Nicolo Immobiliare Ltd | Real estate | 2020 |
| Sanay Holdings Ltd | Real estate | 2019 |
| Sanbol Limited | Wholesale & retail | 2005 |
| Sanchitecture Ltd | Professional & scientific | 2024 |
| Sandha Heating & Plumbing Limited | Construction | 2019 |
| Sandmine Consultancy Limited | Professional & scientific | 2021 |
| Sandringham Investments Limited | Professional & scientific | 1988 |
| Sandstone Lodge Limited | Households | 2015 |
| Sanjaey Consulting Ltd | Real estate | 2021 |
| Sapphire Consultancy Services Limited | Information & communication | 2021 |
| Sapphires Property Ltd | Real estate | 2023 |
| Sara Partners LLP | | 2014 |