| Ramzan & Sons Investments Limited | Real estate | 2009 |
| Raqui | | 1987 |
| Rawalair Ltd | Transport & logistics | 2023 |
| React - Acting for Business Ltd | Professional & scientific | 2007 |
| Realworld Employee Surveys Ltd | Administrative & support | 2005 |
| Reconst Limited | Construction | 2021 |
| Redcar Estates Limited | Real estate | 1988 |
| Redfin Models Limited | Wholesale & retail | 2016 |
| Regaline Limited | Professional & scientific | 1976 |
| Regency Polythene and Packaging Limited | | 1982 |
| Revision Flooring Company Limited | | 1983 |
| RGL & GE Ebsworth Limited | Construction | 2005 |
| Rhones Building Services Ltd | Construction | 2017 |
| Risetech Limited | Professional & scientific | 2017 |
| Risk I.T. Ltd | Information & communication | 2003 |
| Riverain Bowls Club Ltd | Arts & recreation | 1986 |
| Riverglide Limited | Information & communication | 2009 |
| Riverplace Properties Limited | Real estate | 2001 |
| RMV Solutions Ltd | Construction | 2014 |
| RO 102 Limited | Construction | 1961 |
| RO Frome Limited | Construction | 2005 |
| Robin Goodchild Associates Limited | | 1981 |
| Roebuck Court Management Company Limited | Households | 1978 |
| Roger Kimber Limited | Professional & scientific | 2004 |
| Romeo's Limited | Other services | 1989 |
| Romsoft Limited | Professional & scientific | 2004 |
| Rossbriar Limited | Professional & scientific | 1983 |
| Rougewell Limited | | 1978 |
| Rowlandson Investments Limited | Construction | 1961 |
| Rowlandson Properties Limited | Extraterritorial | 1964 |
| Roxywest Limited | | 1987 |
| ROY Carter Limited | Wholesale & retail | 1981 |
| Roysia Flooring Limited | Construction | 2003 |
| Royston Glass Works | | 1989 |
| Royston Masonic Hall Company Limited | Other services | 1993 |
| Royston Services Limited | Other services | 2003 |
| RSK Limited | Professional & scientific | 2006 |
| RSL Agri Limited | Real estate | 2018 |
| RTB London Ltd | Hospitality | 2017 |
| Russell Smith Farms Limited | Agriculture & fishing | 2007 |
| Russo Real Estate Limited | Real estate | 2006 |
| RWH Travel Limited | Administrative & support | 1953 |
| Ryefield Engineering Company Limited | Manufacturing | 1990 |
| S & S Haulage Limited | | 1986 |
| S. & D. Electrics (Barnet) Limited | | 1979 |
| S. Graham Rowlandson & Co. Limited | Administrative & support | 1966 |
| S.A.H. Distribution Limited | Professional & scientific | 1996 |
| S.Hille & Co.(Holdings)Limited | Real estate | 1964 |
| S.J.Waterman Limited | Construction | 1960 |
| S.K Enterprises Private Limited | Wholesale & retail | 2012 |
| Safepurpose Property Management Limited | Households | 1996 |
| SAM Car Wrapping Ltd | Manufacturing | 2025 |
| Samad Property Investments Limited | Real estate | 2016 |
| Sanders (Investments) Limited | Financial services | 1960 |
| Satyam Investments Limited | Real estate | 1993 |
| Sawmills Bristol Limited | Arts & recreation | 2026 |
| SC Technologies LP | | 2002 |
| Scott Blain Insurance Consultants Limited | Financial services | 2000 |
| SDF Trading Limited | Wholesale & retail | 2011 |
| SDG Investments Limited | Financial services | 2001 |
| Sea Titan Group UK Ltd | Administrative & support | 2023 |
| Sealtag Limited | Professional & scientific | 1982 |
| Season Master Double Glazing Limited | Manufacturing | 1975 |
| Second Take Ltd | Information & communication | 2026 |
| Selsea Fish & Lobster Co. Limited | Manufacturing | 1994 |
| Senior Aerospace Limited | Professional & scientific | 1973 |
| Senior Automotive Limited | Professional & scientific | 1986 |
| Senior Engineering Investments Limited | Professional & scientific | 1968 |
| Senior Flexonics Limited | Professional & scientific | 2004 |
| Senior Trustee Limited | Professional & scientific | 1986 |
| Sevenpace Limited | | 1983 |
| Seventh-Day Adventist Association Limited | Administrative & support | 1906 |
| Seventh-Day Adventist Trust Company Limited | Administrative & support | 1982 |
| Shared Xpertise Limited | Real estate | 2003 |
| Shebana Gifts Limited | Wholesale & retail | 2007 |
| Sheerwater Healthcare Limited | Health & social care | 2008 |
| Sheerwater House Holdings Limited | Financial services | 2017 |
| Shepfield Batteries Limited | Extraterritorial | 1992 |
| Signature Fires Limited | Construction | 2009 |
| Sika Limited | Manufacturing | 1927 |
| Silver Court Residents Company Limited | Households | 1998 |
| Silvio's Quality Sandwich Bars Limited | Hospitality | 1987 |
| Sindbad (UK) Limited | Professional & scientific | 2002 |
| Skillsphe (UK) Heat Exchangers Limited | Extraterritorial | 2019 |
| Skyline Loft Conversions (London) Limited | | 1989 |
| Soccersums Ltd | Education | 2023 |
| Softsell Ltd | Information & communication | 2015 |
| Solarap Limited | Manufacturing | 2024 |
| Solaripe Ltd | Extraterritorial | 2010 |
| Solartek Films Limited | Construction | 2001 |
| Solid Management & Consultancy Services Limited | Professional & scientific | 1997 |
| Soto Performing Arts Ltd | Arts & recreation | 2018 |
| Southbank Publishing Limited | Information & communication | 2003 |
| Southdowns Manor Limited | Hospitality | 2013 |
| Southwold Road (Block E) Freehold Company Limited | Real estate | 2007 |
| Space Crate Ltd | Arts & recreation | 2016 |
| Sparc Electrical Limited | Construction | 2004 |
| Sparshotts (Fruiterers) Limited | Manufacturing | 1961 |
| Speedenvoy Limited | | 1985 |
| Speyhawk Place Residents Company Limited | Real estate | 2000 |