| RSB Assure Ltd | Professional & scientific | 2026 |
| RSB Synergy Ltd | Financial services | 2025 |
| RSF Management Solutions Ltd | Information & communication | 2010 |
| RSM Solutions Ltd | Information & communication | 2025 |
| RSP UK Trader Ltd | Construction | 2019 |
| Rspukk Ltd | Real estate | 2025 |
| Rssh Ltd | Wholesale & retail | 2025 |
| RTB Engineering Limited | Manufacturing | 2010 |
| Rtndco Limited | Administrative & support | 2023 |
| Ruah Solutions Limited | Administrative & support | 2025 |
| Rubber Brains Ltd | Information & communication | 2026 |
| Rubec Global Limited | Administrative & support | 2012 |
| Rubin Medical Services Ltd | Health & social care | 2016 |
| Ruby Capital Investments Limited | Financial services | 2025 |
| Ruchik Brews Ltd | Wholesale & retail | 2025 |
| Rudbygroup Ltd | Hospitality | 2024 |
| Rudest Brand Ltd | Wholesale & retail | 2025 |
| Rudzi Community Interest Company | Education | 2023 |
| Ruffy Bullard & Lucinda Wright Interior Designs Limited | Other services | 2013 |
| Rugby Cleaning Services Ltd | Financial services | 2025 |
| Rugby Cubs Ltd | Education | 2020 |
| Rugged Online Limited | Wholesale & retail | 2021 |
| Rugged Reclaim Ltd. | Wholesale & retail | 2016 |
| Ruined Running Events Ltd | Arts & recreation | 2025 |
| RUK Property Maintenance Limited | Transport & logistics | 2026 |
| Rukan Ltd | Information & communication | 2026 |
| RUM & Resin Printing LLP | | 2021 |
| Rumble Tums Meals Limited | Hospitality | 2020 |
| Run MAD Limited | Other services | 2023 |
| Runebyte Ltd | Information & communication | 2025 |
| Runger Events Ltd | Arts & recreation | 2025 |
| Runica Ltd | Professional & scientific | 2025 |
| Runner Bean Web Design Limited | Information & communication | 2013 |
| Running Ostrich Limited | Transport & logistics | 2015 |
| Runnymede Basketball Club CIC | Education | 2021 |
| Runway Pigs Limited | Agriculture & fishing | 2025 |
| Rushbrooke Knife Company Ltd | Manufacturing | 2023 |
| Rushly Ltd | Information & communication | 2026 |
| Rushmere Technology Limited | Professional & scientific | 2012 |
| Rusholme Prime Properties Ltd | Real estate | 2024 |
| Russell Scientific Instruments Limited | Manufacturing | 2022 |
| Russon Campbell (Oundle) Limited | Construction | 2019 |
| Russon Campbell Developments Limited | Construction | 2018 |
| Rustic Renovations Limited | Real estate | 2024 |
| Rusticodeli Ltd | Wholesale & retail | 2024 |
| Ruston Planning Limited | Professional & scientific | 2013 |
| Ruth Duffield Lactation Ltd | Health & social care | 2025 |
| Ruth Ingram Associates Ltd | Professional & scientific | 2012 |
| Ruthven Property Ltd | Extraterritorial | 2024 |
| Rutland Associates Limited | Administrative & support | 2019 |
| Rutonga Ltd | Wholesale & retail | 2021 |
| Rvckstar Ltd | Wholesale & retail | 2020 |
| RVE Property Ltd | Real estate | 2021 |
| Rvercrest Group Ltd | Wholesale & retail | 2025 |
| RVN Consultancy Ltd | Other services | 2021 |
| Rvwest Ltd | Administrative & support | 2021 |
| RW & SW School-Wear Limited | Wholesale & retail | 2014 |
| RW Competitions Limited | Arts & recreation | 2026 |
| RW Online Ltd | Professional & scientific | 2022 |
| RWE Solutions Ltd | Professional & scientific | 2026 |
| RXL Technologies Ltd | Wholesale & retail | 2025 |
| Rxperience Events Ltd | Administrative & support | 2025 |
| Ryan Electrical Limited | Construction | 2008 |
| Ryan Wingate Golf Ltd | Wholesale & retail | 2025 |
| Ryanmangansitblog Limited | Information & communication | 2017 |
| Ryanmcounselling Ltd | Health & social care | 2021 |
| Rybinska Technology Ltd | Information & communication | 2023 |
| Rycote Microphone Windshields Limited | Manufacturing | 1994 |
| Rysun Limited | Real estate | 2000 |
| Rytros LAB Solutions Ltd | Wholesale & retail | 2026 |
| Rzari Foods Ltd | Extraterritorial | 2016 |
| Rzari Limited | Information & communication | 2012 |
| S & B Group Limited | Financial services | 2017 |
| S & D Groundwork (Suffolk) Ltd | Administrative & support | 2016 |
| S & M Risby Cafe Limited | Administrative & support | 2019 |
| S & P Oaktree Limited | Professional & scientific | 2018 |
| S Buss Development Ltd | Information & communication | 2011 |
| S Colomb Ltd | Professional & scientific | 2023 |
| S Dean Building Services Limited | Construction | 2011 |
| S G Machining Solutions Limited | Manufacturing | 2009 |
| S Gold Ltd | Arts & recreation | 2024 |
| S Houghton Accounting Ltd | Professional & scientific | 2018 |
| S I Property Maintenance Limited | Real estate | 2004 |
| S J Baldock Ltd | Professional & scientific | 2013 |
| S J Daniel Construction Ltd | Construction | 2023 |
| S J Hitchcock Ltd | Construction | 2012 |
| S Nash Roofing Ltd | Construction | 2015 |
| S P Rust (Farrier) Limited | Agriculture & fishing | 2013 |
| S White Services Ltd. | Construction | 2015 |
| S&A 3 UK Ltd | Transport & logistics | 2019 |
| S&A Consultancy Ltd | Professional & scientific | 2025 |
| S&A Rentals Ltd | Real estate | 2021 |
| S&E Orajuba Ltd | Real estate | 2026 |
| S&S Luxury Constructions Ltd | Construction | 2022 |
| S&T Abodes Ltd | Real estate | 2025 |
| S&V Retailing Limited | Wholesale & retail | 2025 |
| S&W Financial Solutions Ltd | Professional & scientific | 2021 |
| S. C. Cranston & Company Limited | Real estate | 1960 |
| S.A.S Hydraulics Limited | Manufacturing | 2019 |
| S.A.W Resourcing Ltd | Administrative & support | 2024 |