| Radnevo Ltd | Wholesale & retail | 2024 |
| Radvasta Limited | Extraterritorial | 2007 |
| RAE Cornwell Mckeown Limited | Professional & scientific | 2015 |
| Rafal Tomasz Suliga Limited | Extraterritorial | 2025 |
| Rafmo Ltd | Real estate | 2026 |
| Ragana Recruitment Limited | Administrative & support | 2023 |
| Ragar Relocations Limited | Households | 2022 |
| Rahmini Logistics 2025 Ltd | Transport & logistics | 2025 |
| Rainbow Stout Productions Ltd | Arts & recreation | 2024 |
| Rainy Days Pictures Limited | Arts & recreation | 1996 |
| Raiqc Ltd | Health & social care | 2015 |
| Raised by the Bar Limited | Education | 2015 |
| RAJ Oxford Ltd | Hospitality | 2013 |
| Raja Brothers (Oxford ) Limited | Real estate | 2022 |
| Raja Yoga Ltd | Real estate | 2025 |
| Raji Ltd | Real estate | 2024 |
| Rako Performance Limited | Wholesale & retail | 2026 |
| Rakoya Limited | Transport & logistics | 2021 |
| Rama Builders Oxford Ltd | Construction | 2018 |
| Rama Property Solutions Ltd | Construction | 2026 |
| Ramen Koncept Ltd | Hospitality | 2025 |
| Ramfam Services Limited | Professional & scientific | 2013 |
| Rami Beauty Limited | Other services | 2019 |
| Ramica Medical Ltd | Information & communication | 2026 |
| Ramis Edits Ltd | Information & communication | 2026 |
| Ramona's Therapy Limited | Other services | 2018 |
| Ramos Nests Ltd | Construction | 2020 |
| Rams Quantity Surveying Limited | Construction | 2015 |
| Ramsdale Management Ltd | Real estate | 2022 |
| Ramsden ORR Limited | Information & communication | 2006 |
| Ramztek Ltd | Information & communication | 2023 |
| Rana Homes (Summertown) Limited | Construction | 2020 |
| Randall Communications Limited | Information & communication | 2014 |
| Rangel Motorcycle Limited | Wholesale & retail | 2026 |
| Raniga Property Investment Limited | Real estate | 2022 |
| Ranoush Catering Limited | Hospitality | 2026 |
| RAO Management Services Ltd | Professional & scientific | 2010 |
| Rapid Courier Limited | Transport & logistics | 2021 |
| Rapid Indigo Ltd | Information & communication | 2022 |
| Rapid Plumbing & Electrics Ltd | Construction | 2026 |
| Rapid Skills Limited | Arts & recreation | 2026 |
| Rapidliving Properties Ltd | Real estate | 2023 |
| RAR Global Ltd | Wholesale & retail | 2026 |
| Rara Estates Limited | Real estate | 2020 |
| Ratio F&B Limited | Hospitality | 2016 |
| Rattan Logistics Ltd | Transport & logistics | 2026 |
| Rattanology Ltd | Manufacturing | 2024 |
| Rauf Niyar Properties Ltd | Real estate | 2024 |
| Rauni Logistics Limited | Transport & logistics | 2024 |
| Ravenhall IT Solutions Limited | Information & communication | 1998 |
| Ravenloop Design Limited | Arts & recreation | 2016 |
| Ravenscourt Builders Ltd | Construction | 2011 |
| RAW Brand Limited | Professional & scientific | 2018 |
| RAW Entertainment Limited | Extraterritorial | 2017 |
| RAW Hospitality Limited | Hospitality | 2017 |
| RAW Workshop | Manufacturing | 1992 |
| Rawmotion Partners Limited | Wholesale & retail | 2025 |
| RAY Valley Solar Limited | Energy | 2019 |
| Rayan Intelligence Limited | Administrative & support | 2018 |
| Rayleigh LOW Carbon Hydrogen Limited | Administrative & support | 2022 |
| Raypat Limited | Real estate | 1963 |
| Rays & Glow Ltd | Other services | 2025 |
| RB Beauty Lounge Ltd | Other services | 2026 |
| RB Investment Properties Ltd | Real estate | 2020 |
| Rbfurtado Limited | Wholesale & retail | 2023 |
| RBJ Immigration Ltd | Professional & scientific | 2024 |
| RBR Engineering Solutions Limited | Professional & scientific | 2015 |
| Rc-Max Products Ltd | Manufacturing | 2017 |
| RCB Consulting Ltd | Professional & scientific | 2026 |
| Rccg Lighthouse Witney | Other services | 2026 |
| Rcluzzi Limited | Health & social care | 2017 |
| Rcrookautomotive Ltd | Wholesale & retail | 2024 |
| Rcube Labs Ltd | Information & communication | 2019 |
| RD Beverages Ltd | Administrative & support | 2013 |
| Rdmi Services Limited | Construction | 2012 |
| Rdmt Enterprises Ltd | Hospitality | 2024 |
| RDR Ortholegal Ltd | Health & social care | 2025 |
| Re-Aim Therapeutics Ltd | Professional & scientific | 2024 |
| Re-New Air Limited | Construction | 2018 |
| Reachup Ltd | Hospitality | 2022 |
| Reactive Technologies Limited | Energy | 2010 |
| Reactive Technologies UK Limited | Energy | 2016 |
| Readerama Ltd | Information & communication | 2025 |
| Readshield Limited | Construction | 1988 |
| Ready JOB Ltd | Administrative & support | 2022 |
| Ready Teddy Go Limited | Wholesale & retail | 2010 |
| Readyformed Solutions Ltd | Information & communication | 2022 |
| Real AI Ltd | Information & communication | 2023 |
| Real Educational Research Investments Limited | Real estate | 2004 |
| Realisis Limited | Professional & scientific | 2002 |
| Reallight Semiconductor Ltd | Wholesale & retail | 2021 |
| Realservice Ltd | Professional & scientific | 1998 |
| Realuk Limited | Real estate | 2020 |
| Reanimate Ltd | Information & communication | 2014 |
| Rebecca Mooney Consulting Limited | Professional & scientific | 2019 |
| Rebel & Love Ltd | Wholesale & retail | 2022 |
| Rebel Pharma Services Ltd | Professional & scientific | 2023 |
| Rebellion 2000 AD Ltd | Information & communication | 2018 |
| Rebellion Asset Holdings Ltd | Professional & scientific | 2018 |
| Rebellion Central Holdings Ltd | Professional & scientific | 2020 |