| Rhaeadru Ltd | Administrative & support | 2026 |
| Rhys Knowles Limited | Administrative & support | 2012 |
| Rices Recovery Limited | Other services | 2017 |
| Richard Davies Holdings Ltd | Real estate | 2021 |
| Richmond Road (Towcester) Management Limited | Real estate | 1985 |
| Ristorio Cardiff Limited | Hospitality | 2016 |
| Robert Purvis Consulting Limited | Professional & scientific | 2021 |
| Robomatic Ltd | Information & communication | 2014 |
| Rockfield FEL LLP | | 2015 |
| Rockfield Property Services Ltd | Construction | 2026 |
| Roka Bell Ltd | Real estate | 2024 |
| Rome Flooring Ltd | Construction | 2021 |
| Roper Finishing Solutions Limited | Professional & scientific | 2009 |
| Ross Technical Equipment Company Limited | Manufacturing | 2012 |
| Rosybee Limited | Agriculture & fishing | 2011 |
| Route-Led Group Limited | Education | 2021 |
| RP Adventure Tours Ltd | Administrative & support | 2026 |
| Ryder Homes Ltd | Real estate | 2020 |
| S&R Holiday LET Management Limited | Real estate | 2024 |
| S.B.M (USK) Management Company Limited | Households | 2019 |
| S.E. Cooper Ironworkers & Blacksmiths Limited | Manufacturing | 2018 |
| S.R. Hyslop & Company Limited | Other services | 1923 |
| S.S.Coltart Therapy Limited | Health & social care | 2023 |
| Safety Engineering Consultants Limited | Professional & scientific | 2020 |
| Salad Skills Limited | Education | 2012 |
| Salmonstone Ltd | Administrative & support | 2018 |
| Sammy Snake Ltd | Information & communication | 2021 |
| Samuel Ryde Ltd | Arts & recreation | 2020 |
| Sarah Chatterton Speech and Language Therapy Ltd | Administrative & support | 2014 |
| SAS Accounting Ltd | Professional & scientific | 2023 |
| Satya Retreats Ltd | Hospitality | 2026 |
| SAY IT Well Ltd | Arts & recreation | 2021 |
| SBS Salvage Limited | Other services | 2011 |
| Scandi Studio Ltd | Other services | 2015 |
| Scenery Fencing UK Limited | Manufacturing | 2009 |
| School Breathe CIC | Health & social care | 2022 |
| Scoffs Food Limited | Hospitality | 2021 |
| Scott Associates Safety Consulting Ltd | Professional & scientific | 2019 |
| Scrap Cars Cardiff Ltd | Other services | 2021 |
| Scriptorium Limited | Professional & scientific | 1998 |
| Seacliff Garden Ltd | Extraterritorial | 2012 |
| Seacliff House (Ventnor) Limited | Administrative & support | 2008 |
| Seanav Limited | Information & communication | 2016 |
| Searchpedia Ltd | Professional & scientific | 2025 |
| Secret Sauce Sales Consultancy Ltd | Professional & scientific | 2025 |
| Sedbury Park Consortium | | 1996 |
| Seers Courier Services Ltd | Transport & logistics | 2025 |
| Seers Couriers Limited | Transport & logistics | 2020 |
| Seers Hospitality Ltd | Hospitality | 2024 |
| Seftron Limited | Professional & scientific | 1999 |
| Semper Fidelis Haulage and Construction Ltd | Transport & logistics | 2023 |
| Senojtek Ltd | Information & communication | 2023 |
| Sense of Self Ltd | Other services | 2025 |
| Sentomol Limited | Professional & scientific | 2011 |
| SEP Automotive UK Ltd | Professional & scientific | 2020 |
| Seren Kitchen & Property Developments Limited | Construction | 2025 |
| Service Management Connect Limited | Information & communication | 2009 |
| Seven Crows Ltd | Other services | 2024 |
| SFK Holdings Ltd | Agriculture & fishing | 2026 |
| SFR Building Ltd | Construction | 2024 |
| SFS Electrical Services Limited | Construction | 2018 |
| SG Events Ltd | Hospitality | 2012 |
| Shampooch Dog Spa Ltd | Other services | 2024 |
| Sharpe Masonry Limited | Construction | 2012 |
| Sheppard Davies Asset Management Ltd | Financial services | 1998 |
| Shine Consulting Limited | Professional & scientific | 2016 |
| Shire Paving Ltd | Construction | 2019 |
| Shires Law (Gloucester) Ltd | Professional & scientific | 2015 |
| Sigtech Rail Limited | Professional & scientific | 2024 |
| Sikh Empire Ltd | Wholesale & retail | 2023 |
| Siltbuster Limited | Water & waste | 2003 |
| Simbay Ltd Company Limited | Administrative & support | 2016 |
| Simi Kitchens Limited | Wholesale & retail | 2009 |
| Simon N Khoury Limited | Health & social care | 2010 |
| Simplify Ergonomics Limited | Professional & scientific | 2007 |
| Simply Catnip Ltd | Wholesale & retail | 2016 |
| Skenfrith Angling Club Limited | Agriculture & fishing | 2015 |
| Skidsteer Hire Solutions Ltd | Administrative & support | 2023 |
| Skymark Financial Ltd | Professional & scientific | 2019 |
| SL & JP Properties Ltd | Real estate | 2025 |
| Slabb Ltd | Manufacturing | 2025 |
| Slingshot Design Limited | Information & communication | 2010 |
| SLT Consultancy Limited | Administrative & support | 2009 |
| Socialight Stroud Ltd | Hospitality | 2019 |
| Society of the Sacred Cross | Other services | 2010 |
| Sociitech Limited | Extraterritorial | 2024 |
| Solrose Limited | Professional & scientific | 1964 |
| Somerfield Storage Ltd | Real estate | 2026 |
| Sonicbond Promotions Ltd | Arts & recreation | 2015 |
| SOS Testing Ltd | Professional & scientific | 2012 |
| Sosocialgb Ltd | Professional & scientific | 2017 |
| South Wales Truck and Trailer Repairs Limited | Manufacturing | 2017 |
| Southern Shaolin Arts Limited | Arts & recreation | 2025 |
| Specialist Metal Products Limited | Other services | 2014 |
| Spice Trail 24 Ltd | Hospitality | 2022 |
| Sportiva School of Motoring Ltd | Education | 2024 |
| Spray Revolution Ltd | Construction | 2021 |
| Springdent Ltd | Health & social care | 2025 |
| SRA Building Ltd | Construction | 2023 |
| Standing Start Solutions Limited | Professional & scientific | 2010 |