| RNC Roofing Limited | Wholesale & retail | 1991 |
| Rodrigo Carelli Ltd | Education | 2024 |
| Rohirrim Ltd | Other services | 2024 |
| RPW Electrical Services Ltd | Construction | 2023 |
| RRJ Therapy Ltd | Health & social care | 2024 |
| RRV Tuinalele Ltd | Wholesale & retail | 2024 |
| RSA Associates Limited | Professional & scientific | 2013 |
| RUA Property Limited | Professional & scientific | 2023 |
| Rusty Shackle Ltd | Arts & recreation | 2012 |
| RWG Financial Planning Limited | Professional & scientific | 2020 |
| RWM Estate Agents Ltd | Real estate | 2014 |
| Rython Limited | Administrative & support | 2021 |
| S George Services Limited | Administrative & support | 2007 |
| Sabrina Deans Properties Ltd | Real estate | 2025 |
| Safe Space - Resilience in Nature CIC | Education | 2026 |
| Safe Supportable Solutions Limited | Administrative & support | 2011 |
| Safeguard Engineering Limited | Professional & scientific | 2013 |
| Sage Ideas Limited | Information & communication | 2007 |
| Salam Fruit & VEG Ltd | Hospitality | 2019 |
| Samuel David Limited | Other services | 2007 |
| Saplo Training Services Ltd | Education | 2025 |
| Sappenin Project Ltd | Manufacturing | 2022 |
| SAR Drivers North East Ltd | Transport & logistics | 2018 |
| Sarah’S Daughter Ltd | Wholesale & retail | 2026 |
| Sarra Retail Ltd | Wholesale & retail | 2018 |
| Satin & Lace Events Hire Limited | Hospitality | 2020 |
| Satin & Lace Vehicles Limited | Administrative & support | 2019 |
| SB Refrigeration South West Ltd | Manufacturing | 2024 |
| SB Sales Solutions Limited | Professional & scientific | 2018 |
| Scandlin Ltd | Professional & scientific | 2015 |
| Scarlet Oak Theatre Limited | Arts & recreation | 2023 |
| Scarlet Rights (Dormant) Limited | Information & communication | 2025 |
| Scarlet Rights 2 Limited | Information & communication | 2021 |
| Scarlet Rights 4 Limited | Information & communication | 2022 |
| Scarlet Rights 5 Limited | Information & communication | 2023 |
| Scarlet Rights 6 Limited | Information & communication | 2024 |
| Scarlet Rights 7 Limited | Information & communication | 2025 |
| Scarlet Rights Limited | Arts & recreation | 2019 |
| SD Beauty Ltd | Wholesale & retail | 2012 |
| SD Detailing Ltd | Construction | 2025 |
| Secure Micro Ltd | Information & communication | 2017 |
| Sedbury Park (Millennium 2001) Belfry Limited | Extraterritorial | 2001 |
| Sedbury Space | Other services | 2017 |
| Seer Textiles Limited | Wholesale & retail | 2013 |
| Senior Advice Limited | Professional & scientific | 2010 |
| Serai Network CIC | Education | 2023 |
| Sergejs Ltd | Transport & logistics | 2015 |
| Service Stamp Ltd | Information & communication | 2026 |
| SET in Steel Ltd | Manufacturing | 2025 |
| Seva Card Limited | Information & communication | 2007 |
| Seven Consulting Services Limited | Information & communication | 2024 |
| Severn Barrage Limited | Extraterritorial | 2021 |
| Severn Quay (Chepstow) Management Company Limited | Extraterritorial | 2016 |
| Severn Quay Limited | Construction | 2014 |
| Severn Quay Properties Limited | Real estate | 2018 |
| Severnside Property Services Limited | Construction | 2000 |
| Severnvale Consultancy Ltd | Education | 2008 |
| Severnvale Limited | Arts & recreation | 2006 |
| Severnvale Riding LLP | | 2014 |
| Seymour Direct Limited | Administrative & support | 1997 |
| Seymourdirect Terminals Limited | Administrative & support | 2012 |
| SGP Trading Limited | Construction | 1978 |
| Shalim Tandoori Ltd | Hospitality | 2025 |
| Shallgreen Ltd | Real estate | 2020 |
| SHC Creative Solutions Ltd | Professional & scientific | 2022 |
| Sheridan Living Ltd | Real estate | 2019 |
| Sheridan Property Ltd | Construction | 2003 |
| Shesaid.So Limited | Other services | 2017 |
| Shilton Investments Limited | Real estate | 1983 |
| Shuizenholdings Ltd | Real estate | 2024 |
| SI Distribution Limited | Information & communication | 2011 |
| Sightsmart Ltd | Professional & scientific | 2020 |
| Sihot UK International Ltd | Information & communication | 2016 |
| Silva Wave Technologies Ltd | Wholesale & retail | 2023 |
| Silver Circle Distillery Limited | Manufacturing | 2018 |
| Simon B Website Development Ltd | Information & communication | 2024 |
| Sirius One Ltd | Construction | 2018 |
| SJ Assessment Limited | Professional & scientific | 2019 |
| SJB Chiro Limited | Health & social care | 2023 |
| Skycliff Properties Limited | Real estate | 2024 |
| Slater Dowell Consulting Ltd | Information & communication | 2024 |
| Sleepyhead Limited | Information & communication | 2008 |
| Smash Care Ltd | Health & social care | 2006 |
| Smith & Brown Bathroom Solutions Ltd | Construction | 2026 |
| Smithies Studio LLP | | 2026 |
| Smithy & Sully Ltd | Construction | 2021 |
| SMS Payroll Ltd | Professional & scientific | 2021 |
| SMS Processing Ltd | Professional & scientific | 2021 |
| Souk Palestine Ltd | Wholesale & retail | 2025 |
| South Monmouthshire Estates (Residential) Limited | Hospitality | 2020 |
| South Monmouthshire Estates Ltd | Real estate | 2018 |
| Southstone Capital Ltd | Financial services | 2026 |
| Southward Properties (Llanharan) Limited | Construction | 2006 |
| Sparkle Tailors Limited | Other services | 2023 |
| SPD Steel Limited | Wholesale & retail | 2024 |
| Special OPS Security Ltd | Administrative & support | 2023 |
| Specialist Structural Steelwork Services Limited | Professional & scientific | 2017 |
| Speedy Deck Ltd | Construction | 2013 |
| Spice IT UP Ltd | Wholesale & retail | 2022 |
| Squirreling Away Ltd | Real estate | 2025 |