| Rubicon Analytics Limited | Information & communication | 2018 |
| Rubix Partners Limited | Administrative & support | 2023 |
| Rubrix Building & Maintenance Limited | Construction | 2011 |
| Ruby London Colney Ltd | Hospitality | 2025 |
| Ruby Red Realty Ltd | Real estate | 2024 |
| Ruddle AQC Limited | Administrative & support | 2025 |
| Rudeboy Films Ltd | Information & communication | 2026 |
| Rudycode Ltd | Information & communication | 2018 |
| RUG Maker Limited | Extraterritorial | 2013 |
| Rug-Maker.Com Limited | Wholesale & retail | 2004 |
| Rujay Music Limited | Information & communication | 2018 |
| Rukmini Patel Limited | Professional & scientific | 2011 |
| Rumbo Ventures SPV I LLP | | 2024 |
| Run St.Albans Ltd | Wholesale & retail | 2010 |
| Running Green Ltd | Professional & scientific | 2006 |
| Rupal Antoniou PR Ltd | Professional & scientific | 2022 |
| Rupert Arnold Investments Watford Limited | Construction | 2019 |
| Rural Learning Limited | Education | 2025 |
| Rush, Bailey & Associates Limited | Health & social care | 2008 |
| Russell and Russell Roofing Ltd | Construction | 1994 |
| Russell Robinson Limited | Administrative & support | 2011 |
| Russell Sell Trading Company Limited(The) | Professional & scientific | 1955 |
| RVI Communications Ltd | Professional & scientific | 2017 |
| RVI Ltd | Professional & scientific | 2024 |
| RVP Accern LLP | | 2021 |
| RVP Calm LLP | | 2020 |
| RW Investments Holdings Ltd | Financial services | 2024 |
| RWD Outlet Ltd | Wholesale & retail | 2022 |
| RWD Outlet Resources Limited | Wholesale & retail | 2025 |
| RWP Floward Secondary LP | | 2023 |
| Rxbaker Ltd | Health & social care | 2026 |
| Ryan Ward Ltd | Other services | 2016 |
| Ryde Property Management Limited | Real estate | 2003 |
| Ryecroft Court Limited | Households | 2020 |
| Ryecroft Medical Services Limited | Health & social care | 2010 |
| Rylance Industries Ltd | Information & communication | 2024 |
| Ryterna UK Limited | Manufacturing | 2012 |
| RZH International Limited | Extraterritorial | 2017 |
| S & a Clothing Spa Limited | Wholesale & retail | 2023 |
| S & D Groundworks Surrey & Sussex Ltd | Construction | 2015 |
| S Alexander Law Ltd | Professional & scientific | 2025 |
| S and a DRY Cleaners Ltd | Other services | 2019 |
| S and K Assets Ltd | Real estate | 2024 |
| S C Carpentry & Locksmith Ltd | Manufacturing | 2012 |
| S Cheadle Transport Ltd | Transport & logistics | 2024 |
| S Clayton (HGV Driving Specialist) Ltd | Professional & scientific | 2018 |
| S J Services (NW) Limited | Construction | 2018 |
| S Jafari Ltd | Real estate | 2025 |
| S K C Plastering Ltd | Construction | 2025 |
| S Lamba & Company Ltd | Professional & scientific | 2025 |
| S P D Plastering Limited | Construction | 2016 |
| S R Professional Tiling Services Limited | Construction | 2025 |
| S S J Contract Services Limited | Professional & scientific | 2005 |
| S&D Platform Hire Ltd | Transport & logistics | 2019 |
| S&S Distro Ltd | Wholesale & retail | 2024 |
| S&T Collections Limited | Administrative & support | 2024 |
| S.G. Consultants Holdings Limited | Construction | 2005 |
| S.I.R Consulting Limited | Professional & scientific | 2015 |
| S.Noble Construction Ltd | Construction | 2011 |
| S1 Investments Limited | Construction | 2020 |
| S41 Electrical Services Ltd | Manufacturing | 2026 |
| SA Car Breakdown Recovery Ltd | Wholesale & retail | 2023 |
| SA Financial Consulting Limited | Professional & scientific | 2015 |
| SA Kuda SPV II, LLP | | 2020 |
| SA Kuda SPV III LLP | | 2021 |
| SA Kuda SPV, LLP | | 2020 |
| SA Solid Works Design Studio Ltd | Professional & scientific | 2022 |
| SAA Fabrications Ltd | Other services | 2018 |
| Saaf Business Ltd | Administrative & support | 2023 |
| Saaz Properties Limited | Real estate | 2019 |
| Saaz Realty Limited | Real estate | 2025 |
| SAB Power Limited | Manufacturing | 2020 |
| Saber Sets Ltd | Manufacturing | 2025 |
| Sable Estates Ltd | Real estate | 2018 |
| Sable Island Containers Ltd | Wholesale & retail | 2013 |
| Sacred Heart Holdings Ltd | Real estate | 2019 |
| Sada Architecture Limited | Professional & scientific | 2011 |
| Safe H Limited | Construction | 2020 |
| Safe Hearts Limited | Education | 2015 |
| Safeguard DX Limited | Administrative & support | 2024 |
| Safehands Projects Limited | Real estate | 2004 |
| Safety Footprint Limited | Construction | 2024 |
| Safety Performance Group Limited | Professional & scientific | 2021 |
| Safi Skye Properties Ltd | Real estate | 2025 |
| Safwat Ltd | Health & social care | 2021 |
| Saga Solutions Ltd | Professional & scientific | 2020 |
| Sahanjali Investment Company Ltd | Real estate | 2020 |
| Sahara's Kitchen Limited | Hospitality | 2025 |
| Sahasra Limited | Information & communication | 2025 |
| Sahil Properties Ltd | Real estate | 2024 |
| Sahl Regen KX Technologies Limited | Professional & scientific | 2025 |
| Sahl Regen Services Limited | Professional & scientific | 2026 |
| Sahl Regen UK Limited | Agriculture & fishing | 2025 |
| Said Abbos Limited | Wholesale & retail | 2025 |
| Saimar Limited | Wholesale & retail | 2020 |
| Saint & Green Limited | Wholesale & retail | 2021 |
| Saint Albans Property Services Limited | Construction | 2026 |
| Saint Land and Development Ltd | Construction | 2020 |
| Sajm Capital Ltd | Professional & scientific | 2021 |
| Salamis & Co Limited | Professional & scientific | 1982 |