| RTG Medical Ltd | Health & social care | 2022 |
| Ruby Legacy Homes Ltd | Construction | 2005 |
| Ruby Properties Kent Ltd | Real estate | 2026 |
| Rudraksh & Co Limited | Health & social care | 2009 |
| Ruehox Limited | Health & social care | 2012 |
| Rupali Restaurant Ltd | Hospitality | 2024 |
| Rural Community Housing Ltd | Construction | 2009 |
| Rushden and Diamonds (2008) Limited | Arts & recreation | 2009 |
| Ruskin Landscapes Limited | Administrative & support | 2013 |
| Ruskin Real Estate Limited | Real estate | 2012 |
| Ruskthorpe Limited | Real estate | 2019 |
| Russell Croci Consulting Limited | Professional & scientific | 2016 |
| Russell Flooring Solutions Limited | Construction | 2025 |
| Ryriro Soirées UK Ltd | Administrative & support | 2026 |
| S & D Banks Ltd | Construction | 2018 |
| S & P Decor Limited | Construction | 2018 |
| S a E Associates Limited | Manufacturing | 2018 |
| S B S Supplies Limited | Transport & logistics | 2011 |
| S G Lomas Consulting Ltd | Professional & scientific | 2013 |
| S J & R G Copeman (Retail) Limited | Agriculture & fishing | 1997 |
| S J P Controls Ltd | Construction | 2016 |
| S J Porter Build Limited | Construction | 2021 |
| S J Scaffolding Limited | Construction | 2012 |
| S Riley Services Limited | Construction | 2016 |
| S Wright Group Ltd | Financial services | 2025 |
| S&P Essex Ltd | Other services | 2026 |
| S. Burke Consulting Limited | Professional & scientific | 2023 |
| S.B.C. Engineering Limited | Transport & logistics | 2005 |
| S.I.A.R. Limited | Real estate | 2021 |
| S.K.D. Electrical Contractors UK Limited | Construction | 2009 |
| S.L. Family Limited | Hospitality | 2025 |
| S.L.C. Southern Landscape and Construction Limited | Construction | 1976 |
| S.Perry Transport Services Limited | Transport & logistics | 2006 |
| S.T. Manufacturing (UK) Limited | Manufacturing | 2006 |
| S4C Trading Ltd | Administrative & support | 2017 |
| S6 Property Services Limited | Real estate | 2013 |
| Saam Wine Company Limited | Wholesale & retail | 2007 |
| Sabry Saweros & Sons (UK) Ltd | Real estate | 2014 |
| Sadhna Harish Limited | Real estate | 2021 |
| Sadie's Kitchen Ltd | Hospitality | 2022 |
| Safe Fire Solutions Limited | Construction | 2023 |
| Safety Nexus - Health and Safety Solutions Ltd | Health & social care | 2026 |
| Safield Properties Ltd | Real estate | 2019 |
| Sage Wizzards Limited | Information & communication | 2007 |
| Sales 64 Ltd | Professional & scientific | 2024 |
| Saleslift Solutions Ltd | Administrative & support | 2024 |
| Salix Accountants Limited | Financial services | 2013 |
| Salus Global Knowledge Exchange Limited | Extraterritorial | 2014 |
| Salustri Ltd | Extraterritorial | 2011 |
| Salvanova Ltd | Manufacturing | 2020 |
| SAM Jones Padel Limited | Arts & recreation | 2024 |
| Same Day Recycling Ltd | Water & waste | 2021 |
| Samuel Marcus Shaw Ltd | Other services | 2024 |
| Sanders Witherspoon Estate Agents Limited | Real estate | 2007 |
| Sanders Witherspoon LLP | | 2007 |
| Sanders Witherspoon Solicitors Limited | Real estate | 2014 |
| Sandmay Ltd | Construction | 2008 |
| Sansom & Sansom Associates Limited | Manufacturing | 2008 |
| Santara Care Homes (Ipswich) Limited | Health & social care | 2025 |
| Santara Holdings Limited | Financial services | 2025 |
| Santhem Care Limited | Health & social care | 2021 |
| Santhem Residences (Shenfield) Limited | Real estate | 2016 |
| Santosh Housing Limited | Real estate | 2024 |
| SAP Contracting Limited | Information & communication | 2019 |
| SAR Workspace Consultants Ltd | Administrative & support | 2017 |
| SAR Workspace London Limited | Administrative & support | 2024 |
| Sarah Michaels Ltd | Households | 2013 |
| Satellite Creative Consulting Limited | Professional & scientific | 2026 |
| Savards Properties Limited | Construction | 2016 |
| Save and Pave Ltd | Wholesale & retail | 2025 |
| Savista Developments Limited | Construction | 2018 |
| SAW Storage Systems Installers Ltd | Construction | 2009 |
| Saxon Accident Repair Group Ltd | Wholesale & retail | 2014 |
| Saxton Capital Projects Limited | Professional & scientific | 2015 |
| Saxton Construction Limited | Construction | 2019 |
| Saxton Interiors Limited | Professional & scientific | 2014 |
| SBG Consultancy Ltd | Professional & scientific | 2025 |
| Sbjb Holdings Ltd | Financial services | 2025 |
| SBS Commercial Finance Ltd | Financial services | 2021 |
| SBS Group Limited | Professional & scientific | 1996 |
| Sbw&Jmt Properties Limited | Real estate | 2024 |
| SC Capital Limited | Financial services | 2021 |
| Scale UP Services Ltd | Information & communication | 2020 |
| Schole Road Ltd | Construction | 2025 |
| Schooner Bay Ltd | Real estate | 2023 |
| Sciessent Limited | Wholesale & retail | 2001 |
| Scoop Dating Limited | Other services | 2021 |
| Scoot and Skates Limited | Wholesale & retail | 2012 |
| Scott Creative Designs Limited | Other services | 2017 |
| Scott Warner Residential Ltd | Real estate | 2025 |
| Scotts Flooring Limited | Construction | 2014 |
| Scrap My Car Essex Limited | Wholesale & retail | 2026 |
| Sculpt 26 Ltd | Arts & recreation | 2024 |
| SD Raised Flooring Limited | Construction | 2015 |
| SE Smart Repairs Ltd | Wholesale & retail | 2023 |
| Sea Level Advisory Limited | Professional & scientific | 2025 |
| Sea-King(Boat Builders)Limited | Manufacturing | 1958 |
| Seaham Hall Estates Ltd | Construction | 2020 |
| Seaham Hall Management Company Limited | Hospitality | 2012 |
| Sears Davies Limited | Arts & recreation | 1972 |