| Sage Hair Studio Ltd | Other services | 2020 |
| Sage Pilates & Wellness Ltd | Arts & recreation | 2025 |
| SAH Pearly Whites Limited | Health & social care | 2016 |
| Sahjanand Ltd | Wholesale & retail | 2020 |
| Sahy Ltd | Hospitality | 2018 |
| SAI Global UK Holdings Limited | Professional & scientific | 2001 |
| SAI Retail Trading Limited | Wholesale & retail | 2025 |
| Saiangan Limited | Real estate | 2026 |
| Sailing Barge MAY: the Bread and Roses Barge CIC | Transport & logistics | 2021 |
| Saint M Ltd | Health & social care | 2025 |
| Saint Scaffolding Limited | Construction | 2023 |
| Salaar Property Limited | Real estate | 2024 |
| Salamanca Management Company Ltd | Extraterritorial | 2016 |
| Salary Brook Vineyard Limited | Agriculture & fishing | 2022 |
| Saleloan Limited | Real estate | 1999 |
| Sales Drive Proactive Limited | Administrative & support | 2014 |
| Salesman Trade Ltd | Construction | 2024 |
| Salie-Parker LLP | | 2022 |
| Salisbury Avenue Freehold Limited | Households | 2024 |
| Salisbury Sales Ltd | Wholesale & retail | 2026 |
| Salluri Limited | Wholesale & retail | 2024 |
| Salman Car Wash Ltd | Administrative & support | 2026 |
| Salo Invest Limited | Real estate | 2022 |
| Salo Mortgage Group Limited | Financial services | 2025 |
| Salon Seven Hair & Nails Limited | Other services | 2011 |
| Salt and Sands Properties Ltd | Hospitality | 2023 |
| Salt Financial Ltd | Administrative & support | 2015 |
| Salty Sea Dog Accessories Ltd | Wholesale & retail | 2025 |
| Salus Services Ltd | Education | 2023 |
| SAM COX Design & Interiors Ltd | Professional & scientific | 2022 |
| SAM Hickmore Ltd | Health & social care | 2019 |
| SAM Pilgrim Ltd | Arts & recreation | 2019 |
| Sam's Aroma House Ltd | Wholesale & retail | 2025 |
| Sam's Electrics Ltd | Construction | 2016 |
| Sam's Vape Ltd | Wholesale & retail | 2025 |
| Sama Homes Ltd | Real estate | 2023 |
| Samad Fast Food Ltd | Hospitality | 2018 |
| Samantha Labs Ltd | Manufacturing | 2020 |
| Sambeck Business Park Ltd | Real estate | 1963 |
| Sambeck Caravans Ltd | Wholesale & retail | 1999 |
| Sambrook Court (Hadley Wood) Management Company Limited | Households | 2020 |
| Sameena Endodontics Ltd | Other services | 2018 |
| Samfar Ltd | Other services | 2021 |
| Samia London Ltd | Wholesale & retail | 2020 |
| Samir Property Rental Ltd | Real estate | 2023 |
| Samira Racine Ltd | Education | 2025 |
| Sammatrix Limited | Construction | 2025 |
| Sammy Care Limited | Public administration | 2022 |
| Samphire & Salt Limited | Hospitality | 2025 |
| Samphire Solutions Limited | Administrative & support | 2012 |
| Sams Medicare Ltd | Health & social care | 2014 |
| Samsir Health Care Limited | Health & social care | 2019 |
| Samuel Pepys Harwich Limited | Hospitality | 2021 |
| San&Ste Haulage Ltd | Transport & logistics | 2019 |
| Sana Iftikhar Ltd | Health & social care | 2026 |
| Sanarya Medics Limited | Other services | 2014 |
| Sanatan Enterprise Ltd | Wholesale & retail | 2026 |
| Sanctuary Lettings (Colchester) Limited | Real estate | 2025 |
| Sand and Gravel Association Limited | Other services | 2000 |
| Sand and Salt Ltd | Wholesale & retail | 2017 |
| Sandamoss Contractors Ltd | Construction | 2023 |
| Sandamoss Limited | Construction | 1974 |
| Sandasa Timber UK Limited | Wholesale & retail | 2025 |
| Sandberg Advisory Ltd | Professional & scientific | 2024 |
| Sanderling Reach Residents Management Company Limited | Households | 2021 |
| Sanders and Sons Ltd | Real estate | 2020 |
| Sanderson Law Limited | Financial services | 2007 |
| Sandilyasa Ltd | Real estate | 2023 |
| Sandman Skip Hire Limited | Real estate | 2002 |
| Sandon Brook Manor Right to Manage Company Limited | Households | 2008 |
| Sands & Sun Ltd | Wholesale & retail | 2020 |
| Sanford House Limited | Health & social care | 2001 |
| Sanfranco Limited | Hospitality | 2016 |
| Sanghavi Holdings Limited | Health & social care | 2025 |
| Sanjeev Arya & Partners Limited | Information & communication | 2023 |
| Sanmai Investments Ltd | Construction | 2021 |
| Sanolytics Ltd | Information & communication | 2025 |
| Santa Cruz Properties Limited | Real estate | 2024 |
| Santa Eulalia Property Limited | Professional & scientific | 2011 |
| Santhakumars Ltd | Real estate | 2025 |
| Sanveera Limited | Hospitality | 2016 |
| Sanvitale Commercial Limited | Real estate | 2017 |
| Sanyaruwa Enterprises Limited | Health & social care | 2016 |
| Sanyasee Limited | Health & social care | 2026 |
| SAP Tools Ltd | Wholesale & retail | 2026 |
| Sapaien Limited | Information & communication | 2025 |
| Sapphire Builders Limited | Construction | 2018 |
| Sapphire Cleaning Services Limited | Administrative & support | 2016 |
| Sapphire Compliance Services Limited | Public administration | 2025 |
| Sapphire Contracting Limited | Households | 2026 |
| Sapphire Property Maintenance Limited | Households | 2011 |
| Sapphire Property Management Ltd | Real estate | 2010 |
| Sapphire Rail Ltd | Construction | 2015 |
| Sapphire Resourcing Limited | Administrative & support | 2022 |
| Sapphire UK Holdings Limited | Financial services | 2020 |
| Sara Carter Training & Consultancy Ltd | Professional & scientific | 2021 |
| Sarah Bagshaw Ltd | Information & communication | 2011 |
| Sarah Bros Group Ltd | Real estate | 2025 |
| Sarah Davies Limited | Professional & scientific | 2011 |
| Sarah Fawkes Design Limited | Information & communication | 2009 |