| Ruby Morris Finance Limited | Administrative & support | 2021 |
| Rugby Mansions Limited | Households | 1981 |
| Rugga Limited | Information & communication | 2026 |
| Rumi Home Services Limited | Administrative & support | 2026 |
| Run Apparel Ltd | Wholesale & retail | 2025 |
| Run Partnerships Ltd | Wholesale & retail | 2025 |
| Run This Town Ltd | Real estate | 2025 |
| Russell M. Tucker Limited | Real estate | 2001 |
| Russell Roadmarks Limited | Construction | 2007 |
| Russet Brown Plains Ltd | Construction | 2022 |
| Ryleigh T M P Limited | Construction | 2023 |
| Rymel Properties Limited | Real estate | 2014 |
| S & a Gregory Limited | Construction | 1997 |
| S & E Electrical Ltd | Professional & scientific | 2021 |
| S & F Owners Limited | Wholesale & retail | 2026 |
| S & P Property Services Limited | Construction | 1994 |
| S & P Services Limited | Construction | 1999 |
| S a Passmore & Co Ltd | Professional & scientific | 2011 |
| S and K PVT Ltd | Hospitality | 2023 |
| S Chana & Co Ltd | Construction | 2013 |
| S Group Maintenance Services Ltd | Construction | 2026 |
| S H Living Ltd | Real estate | 2024 |
| S R Xpress Limited | Transport & logistics | 2025 |
| S Ravenhill Ltd | Professional & scientific | 2024 |
| S&A Tiwana Limited | Financial services | 2021 |
| S&Ec Limited | Real estate | 2024 |
| S&J Usimports Ltd | Wholesale & retail | 2020 |
| S&S Taxis Ltd | Transport & logistics | 2026 |
| S-Hyg Ltd | Health & social care | 2025 |
| S-Kin International Limited | Other services | 2020 |
| S. Tucker Roofing Ltd | Construction | 2023 |
| S.B Electrical & AV Ltd | Construction | 2018 |
| S.C.S.S. London Limited | Administrative & support | 2024 |
| S.I.C 78 Ltd | Other services | 2019 |
| S.P.E.A. Fitting Ltd | Construction | 2024 |
| SA & RM James Properties Limited | Real estate | 2014 |
| SA Cafe Ltd | Hospitality | 2024 |
| Saafa Properties PVT Ltd | Real estate | 2026 |
| SAF Garments Ltd | Wholesale & retail | 2015 |
| Safer Journeys Limited | Transport & logistics | 2024 |
| Safety Management Matters Limited | Administrative & support | 2017 |
| Saffron Edge Limited | Information & communication | 2025 |
| Saffron Matrix Ltd | Construction | 2012 |
| Safrose Ltd | Construction | 2019 |
| Sahdev Investments Ltd | Financial services | 2024 |
| Sahiel Limited | Manufacturing | 2026 |
| Saillte Limited | Construction | 2026 |
| Saim & Co Accountants Limited | Professional & scientific | 2007 |
| Sakera Ltd | Construction | 2017 |
| Saleem Welfare Ltd | Health & social care | 2020 |
| Salisbury Court (Barnet) Management Company Limited | Households | 1982 |
| Salon 182 (Loughton) Ltd | Health & social care | 2023 |
| Salon 182 Essex Ltd | Wholesale & retail | 2025 |
| Salter's Brewery Rickmansworth Limited | Hospitality | 2016 |
| Salthouse Mills Development Ltd | Construction | 2022 |
| Saluja AYE Developments Ltd | Households | 2019 |
| SAM Business Consultants Limited | Professional & scientific | 2016 |
| Samar Limited | Construction | 2009 |
| Samarnitech Limited | Construction | 2013 |
| Samax Holdings Ltd | Real estate | 2019 |
| Sameday Transport Solutions Ltd | Transport & logistics | 2009 |
| Sample Grooming Products Ltd | Other services | 2024 |
| Samsara Marketplace Ltd | Wholesale & retail | 2026 |
| Samydee Designs Limited | Professional & scientific | 2019 |
| Sanctuary Garden Rooms and Lofts Limited | Construction | 2026 |
| Sand in the Studio Ltd | Information & communication | 2024 |
| Sandhu & Sandhu Holdings Limited | Financial services | 2021 |
| Sangeet by Sangeeta Ltd | Arts & recreation | 2025 |
| Sangha Limited | Construction | 2020 |
| Sanhuan Import and Export UK Limited | Wholesale & retail | 2014 |
| Sanovis Medical Limited | Health & social care | 2024 |
| Santa Maria Nuova Limited | Construction | 2022 |
| Santorian Digital Ltd | Information & communication | 2026 |
| Santos J Designs Limited | Administrative & support | 2015 |
| Sarah Brown Ltd | Manufacturing | 2012 |
| Sarena Holdings Limited | Construction | 2014 |
| Sarena House LLP | | 2014 |
| Sarj Ventures Limited | Real estate | 2024 |
| Satgur Transport Ltd | Wholesale & retail | 2020 |
| Save My Time Ltd | Extraterritorial | 2010 |
| Sawkins Brothers Limited | Construction | 2007 |
| SAZ Consult Ltd | Extraterritorial | 2014 |
| SAZ Traders Ltd | Wholesale & retail | 2015 |
| SB Sky Properties Limited | Real estate | 2021 |
| SBW Properties Ltd | Real estate | 2017 |
| Sca-Rr Camps Ltd | Arts & recreation | 2019 |
| Sca-Rr Membership Ltd | Administrative & support | 2010 |
| Sca-Rr SL Ltd | Arts & recreation | 2019 |
| Sca-Rr Tours Ltd | Arts & recreation | 2019 |
| Scan Associates Ltd | Professional & scientific | 2016 |
| Scarbell Services Ltd | Construction | 2019 |
| Scendea Limited | Professional & scientific | 2013 |
| Scire Consulting Ltd | Professional & scientific | 2025 |
| SCN Property Group LLP | | 2022 |
| Scon Limited | Other services | 2012 |
| Scooters! Limited | Wholesale & retail | 1998 |
| Scoth Ltd | Construction | 2025 |
| Scott Johnson Ltd | Administrative & support | 2015 |
| Scribes Print Finishers Limited | Manufacturing | 2004 |
| SCTHERAPY23 Ltd | Health & social care | 2023 |