| Sophie Schofield Ltd | Professional & scientific | 2018 |
| Sophie Seddon Limited | Wholesale & retail | 2022 |
| Sophie's Boutique Bows Limited | Other services | 2020 |
| Sophie’S Boutique Bows Chair Covers and Party Decor Limited | Hospitality | 2023 |
| Sorcerer Holdings Limited | Financial services | 2024 |
| Sorted Storage Limited | Other services | 2025 |
| SOS Contractors Ltd | Construction | 2021 |
| Soteria Rail Ltd | Manufacturing | 2022 |
| Soul Laundry Group Ltd | Hospitality | 2024 |
| Soulleigh Healing & Wellness Studios CIC | Health & social care | 2026 |
| Soultasia Ltd | Arts & recreation | 2021 |
| Sound & Vision Electronics Ltd | Wholesale & retail | 2026 |
| Sound Wave Radio Limited | Information & communication | 2019 |
| Soundsplash Arts Limited | Education | 2016 |
| Sourced Clothing Ltd | Wholesale & retail | 2025 |
| South Coast Payroll Limited | Hospitality | 2023 |
| South Creek Projects Limited | Construction | 2022 |
| South East Corp Group Ltd | Construction | 2020 |
| South East Development Group Ltd | Construction | 2025 |
| South East Fire Systems Ltd | Professional & scientific | 2025 |
| South East Property Development Limited | Construction | 2003 |
| South Eastern Archives Limited | Professional & scientific | 1994 |
| South Eastern Logistics Ltd | Transport & logistics | 2011 |
| South Essex Property Rentals Ltd | Real estate | 2015 |
| South Lodge Estates Limited | Administrative & support | 2020 |
| South Pacific Holidays Ltd | Extraterritorial | 1998 |
| South Shields Commercial Property Limited | Real estate | 2018 |
| South Shields Taxis Ltd | Transport & logistics | 2024 |
| South Side Event Caterers Ltd | Hospitality | 2024 |
| Southbourne Agencies Ltd | Financial services | 2022 |
| Southchurch Avenue Investments Limited | Real estate | 2020 |
| Southchurch Cleaning Co Ltd | Administrative & support | 2024 |
| Southeast Fire Protection Specialists Ltd | Public administration | 2021 |
| Southeast Property Group Ltd | Real estate | 2021 |
| Southeastend Ltd | Wholesale & retail | 2024 |
| Southeastwallcoatings Ltd | Construction | 2023 |
| Southend & Chelmsford Radio Ltd | Extraterritorial | 2013 |
| Southend Bathrooms Ltd | Construction | 2023 |
| Southend Creatives CIC | Arts & recreation | 2025 |
| Southend Enterprises Ltd | Real estate | 2023 |
| Southend Flooring Limited | Construction | 2024 |
| Southend French Polishing (Contractors) Limited | Construction | 2008 |
| Southend Kitesurfing Limited | Arts & recreation | 2013 |
| Southend Lawn Freehold Limited | Real estate | 2022 |
| Southend News Service Ltd | Information & communication | 2022 |
| Southend on Sea Golf Club Limited | Other services | 2010 |
| Southend Seafront Investments Ltd | Real estate | 2020 |
| Southend Surface Care Limited | Administrative & support | 2015 |
| Southend Upvc Limited | Wholesale & retail | 2014 |
| Southern Electrical Discounters Limited | Real estate | 1964 |
| Southern Mortgages (Essex) Ltd | Financial services | 2008 |
| Southways Group Limited | Households | 2016 |
| Southwestend Ltd | Wholesale & retail | 2021 |
| Southwestend Medicals Limited | Health & social care | 2026 |
| Southwood Events Ltd | Professional & scientific | 2017 |
| SP Financial Management Limited | Financial services | 2000 |
| SP Plastering Limited | Construction | 2022 |
| Space Transportation Technologies Limited | Transport & logistics | 2017 |
| SPACE282 (Alexandra ST) Ltd | Administrative & support | 2020 |
| SPACE282 (ELM RD) Ltd | Administrative & support | 2019 |
| SPACE282 (Rayleigh) Ltd | Administrative & support | 2022 |
| SPACE282 Group Limited | Financial services | 2023 |
| Spaces Lettings Ltd | Real estate | 2025 |
| Spacesweets Ltd | Manufacturing | 2022 |
| Spark Theory Limited | Information & communication | 2021 |
| Sparks FLY Media Ltd | Information & communication | 2014 |
| Sparky Film Ltd | Professional & scientific | 2003 |
| Sparky MB Ltd | Construction | 2013 |
| Sparway Management Ltd | Households | 2025 |
| Specfibre Solutions Ltd | Construction | 2026 |
| Specialist Curtain & Track Services Limited | Administrative & support | 2007 |
| Specialist Trace Heating Solutions Ltd | Manufacturing | 2014 |
| Speedcare Ltd | Health & social care | 2014 |
| Speller Property Holdings Ltd | Real estate | 2024 |
| Spencer MAY Consulting Limited | Professional & scientific | 2025 |
| Spfj Finance Limited | Financial services | 2019 |
| Spgm Ltd | Other services | 2024 |
| Sphere Electrical Installations Limited | Construction | 2022 |
| Spica Heart Ltd | Real estate | 2025 |
| Spice of Billericay Ltd | Hospitality | 2023 |
| Spinnaker Global Limited | Administrative & support | 1997 |
| Spire CJL Ltd | Administrative & support | 2013 |
| Spirit Property Services Limited | Administrative & support | 2023 |
| SPK Sales Ltd | Wholesale & retail | 2025 |
| Splash N Swim Ltd | Arts & recreation | 2024 |
| Sport Star Limited | Arts & recreation | 2006 |
| Sports and Hospitality Group Limited | Hospitality | 2023 |
| Sprawling and Osborne Limited | Professional & scientific | 2021 |
| Sprawling Holdings Limited | Financial services | 2021 |
| Spraysafe Sprinkler Installation Ltd | Construction | 2021 |
| Springfield Property Investments LLP | | 2008 |
| Springfield Residential Ltd. | Administrative & support | 1998 |
| Springwell SA Management Ltd | Households | 2024 |
| Spruceoak Limited | Administrative & support | 2023 |
| SPS Hillside Ltd | Professional & scientific | 2021 |
| Square 100 Ltd | Information & communication | 2026 |
| Square Nutrition Ltd | Manufacturing | 2026 |
| Square Spots Limited | Wholesale & retail | 2000 |
| Squid Holdings Limited | Financial services | 2024 |
| Squid Property Services Ltd | Extraterritorial | 2023 |