| Reading Concrete Services Limited | Transport & logistics | 2011 |
| Rebecca Steel Aesthetics Ltd | Health & social care | 2026 |
| Red 6 Tech Ltd | Professional & scientific | 2019 |
| Red Mailer Ltd | Professional & scientific | 2016 |
| Red Maple Consulting Ltd | Professional & scientific | 2018 |
| Redcoat U.K. Ltd | Construction | 1963 |
| Reddings Court (Sandhurst) Management Company Limited | Households | 2018 |
| Redlands Southern Limited | Construction | 2013 |
| Redpole Limited | Extraterritorial | 2011 |
| Redroof Wealth Ltd | Financial services | 2025 |
| Reeve Court Building Management Company Limited | Households | 1998 |
| Reeve Court Estate Management Company Limited | Households | 1998 |
| Reformu Limited | Arts & recreation | 2013 |
| Regexbio Limited | Professional & scientific | 2009 |
| Remar Beck Limited | Professional & scientific | 2024 |
| Rereadz Ltd | Wholesale & retail | 2026 |
| Retba Consulting Ltd | Wholesale & retail | 2020 |
| Reveal Holdings Limited | Administrative & support | 2019 |
| Ribo Workwear Ltd | Manufacturing | 2025 |
| Richmond Green Music Services Ltd | Information & communication | 2024 |
| Riseley Road Flats RTE Company Limited | Real estate | 2002 |
| Rivendale Roof Tiling and Slating Ltd | Construction | 2014 |
| Rivenna IT Consulting Limited | Professional & scientific | 2017 |
| RJM Consulting Berkshire Ltd | Professional & scientific | 2023 |
| RJS Consultancy Limited | Professional & scientific | 2000 |
| RO Properties 2 Ltd | Real estate | 2022 |
| Robin Hill Management Company Limited | Households | 2005 |
| Rockplace Properties Limited | Real estate | 2004 |
| Rombus Packaging Limited | Manufacturing | 2009 |
| Roofing Group Berkshire Ltd | Construction | 2025 |
| Roqubin Ltd | Real estate | 1952 |
| RR Civils & Plant Ltd | Administrative & support | 2023 |
| RSR Sports Limited | Education | 2012 |
| Rtjm Digital International Ltd | Information & communication | 2025 |
| Ruegg & Co Limited | Professional & scientific | 2010 |
| Russellhighbury Properties Limited | Real estate | 2015 |
| S D Rigging Limited | Information & communication | 2009 |
| S Wells Construction Ltd | Construction | 2024 |
| S&E Property Ltd | Construction | 2016 |
| Sacre Group Limited | Professional & scientific | 2022 |
| SAI Trading Ltd | Wholesale & retail | 2013 |
| Salon 55 Academy Limited | Education | 2021 |
| Samphire Padstow Freehold Limited | Households | 2018 |
| Samphire Padstow Management Limited | Real estate | 2011 |
| Sansari Intellect Ltd | Information & communication | 2013 |
| Sarren Education Ltd | Administrative & support | 2024 |
| Saudi Luxury Real Estate Limited | Administrative & support | 2026 |
| SCD Capital Investment Limited | Financial services | 2024 |
| SCD Technology Limited | Manufacturing | 2018 |
| Scios Business Consulting Limited | Professional & scientific | 2006 |
| Scott L P Electrical Services Ltd | Construction | 2014 |
| Scutum Estates Limited | Construction | 1974 |
| Seabs Ltd | Financial services | 2021 |
| Seka Inn Hotel Limited | Hospitality | 2026 |
| Selborne Management Company Limited | Real estate | 2001 |
| Seoul Dynasty Limited | Information & communication | 2024 |
| Sequoia Field Farm Imports Ltd | Wholesale & retail | 2011 |
| Serele Ltd | Health & social care | 2020 |
| Servqual Limited | Information & communication | 2020 |
| Seven Tenths Motion Pictures Limited | Information & communication | 2015 |
| Seventh Floor Communications Ltd | Professional & scientific | 2024 |
| Sgoc Limited | Information & communication | 2014 |
| Shaw PAY Limited | Professional & scientific | 2019 |
| Shay & Eash Property Services Ltd | Real estate | 2024 |
| Shortsound Ltd | Information & communication | 2022 |
| Shot in the Light Limited | Arts & recreation | 1990 |
| Showpiece Limited | Arts & recreation | 1995 |
| Sibit Limited | Other services | 2006 |
| Sienya Ltd | Information & communication | 2018 |
| Signum Signs Limited | Construction | 2009 |
| Silky Ocean Studios Ltd | Information & communication | 2015 |
| Silverwood Growth Advisory Limited | Professional & scientific | 2026 |
| Simply HR Limited | Professional & scientific | 2002 |
| Simulearn Ltd | Information & communication | 2025 |
| Sire Technology Limited | Information & communication | 1993 |
| SIX Foot Investments Ltd | Real estate | 2025 |
| SJA Interiors Ltd | Professional & scientific | 2026 |
| Skate Hangar Limited | Wholesale & retail | 2026 |
| Skinners Green Barns (Newbury) Management Limited | Households | 1999 |
| SKV Pharma Limited | Wholesale & retail | 2026 |
| Slice Signage Limited | Professional & scientific | 2024 |
| Smart Coastal Property Ltd | Real estate | 2024 |
| Smith Brown Properties Ltd | Real estate | 2024 |
| Smith Haulage Limited | Water & waste | 2024 |
| Smith Tyres Limited | Wholesale & retail | 2024 |
| SMS Partners Ltd | Education | 2025 |
| Snow Garden Maintenance & Landscape Management Ltd | Construction | 2013 |
| Snowball Consulting Services Ltd | Professional & scientific | 2023 |
| Solarchart Limited | Other services | 2000 |
| Sonder Dance CIC | Arts & recreation | 2026 |
| Sonnie LOW Ltd | Professional & scientific | 2024 |
| Sophie Hathaway Ltd | Real estate | 2026 |
| Soul Purpose Records Limited | Information & communication | 2004 |
| Southbank Software Limited | Information & communication | 2021 |
| Space Filler Ltd | Education | 2025 |
| Spanforward Property Management Limited | Households | 1995 |
| Spectus Energy Limited | Manufacturing | 2001 |
| Speedy Cleaning Services Ltd | Other services | 2013 |
| Springbok Junction Limited | Wholesale & retail | 2026 |
| Springhill Court Bracknell Management Limited | Households | 1987 |