| Rentsecure Solutions Ltd | Real estate | 2025 |
| Rentwell Group Limited | Real estate | 2025 |
| Renu Consultancy Ltd | Manufacturing | 2011 |
| Renugen Limited | Wholesale & retail | 2010 |
| Renure Limited | Wholesale & retail | 2017 |
| Renvillo Ltd | Wholesale & retail | 2025 |
| Repair for YOU Ltd | Construction | 2021 |
| Repair Guys Workshop Ltd | Wholesale & retail | 2024 |
| Repair My TEK Ltd | Other services | 2019 |
| Repair Partner Network Limited | Construction | 2013 |
| Repair Protect Ltd | Construction | 2019 |
| Repair Simply Ltd | Other services | 2022 |
| Repalto Ltd | Information & communication | 2025 |
| Repast & Repose Ltd | Administrative & support | 2012 |
| Repetitive Energy Company Limited | Professional & scientific | 2013 |
| Replab Consulting Ltd | Professional & scientific | 2022 |
| Replica Team Ltd | Information & communication | 2024 |
| Repobot UK Ltd | Information & communication | 2019 |
| Reposx Global Ltd | Wholesale & retail | 2024 |
| Repuserve Ltd | Information & communication | 2023 |
| Repute Agency Ltd | Wholesale & retail | 2025 |
| Reputy Ltd | Information & communication | 2018 |
| Repvos Limited | | 1969 |
| Repzone Fitness Ltd | Wholesale & retail | 2025 |
| Requirox Ltd | Wholesale & retail | 2025 |
| Rerrie Electrical Ltd | Construction | 2021 |
| Resa Homes Limited | Real estate | 2023 |
| Resala Services Ltd | Professional & scientific | 2014 |
| RESALE4U Ltd | Wholesale & retail | 2024 |
| Rescape Innovation Limited | Administrative & support | 2017 |
| Research and Development Solutions Group Ltd | Information & communication | 2025 |
| Research Recruiters Ltd | Professional & scientific | 2019 |
| Researchers Crew Consulting Limited | Construction | 2025 |
| Resedebri New Life Ltd | Wholesale & retail | 2026 |
| Reserv Group Limited | Professional & scientific | 2022 |
| Reserve Book Go Ltd | Hospitality | 2017 |
| Reserve London General Limited | Financial services | 2025 |
| Reservoir Data Limited | Administrative & support | 2024 |
| Reset Retreats Ltd | Hospitality | 2025 |
| Resfeber Solution Ltd | Professional & scientific | 2015 |
| Resident Connection Limited | Real estate | 2023 |
| Resident Management (01) Co Ltd | Households | 2018 |
| Residential Asset Management Limited | Real estate | 2018 |
| Residential Connect Ltd | Real estate | 2016 |
| Residential Rooms London Ltd | Real estate | 2014 |
| Residential Storage Limited | Transport & logistics | 2025 |
| Residian Capital Limited | Real estate | 2021 |
| Residian Limited | Real estate | 2021 |
| Resilience Health Ltd | Professional & scientific | 2020 |
| Resilience Sustainable Solutions Ltd | Professional & scientific | 2014 |
| Resilient City Limited | Information & communication | 2019 |
| Resilio (Defence and Security) Ltd | Information & communication | 2014 |
| Resilio Ltd | Information & communication | 2011 |
| Resin Bound Maintenance Ltd | Construction | 2025 |
| Resin Driveways (NW) Ltd | Construction | 2017 |
| Resinbound Driveways Ltd | Construction | 2024 |
| Resincrete Limited | Administrative & support | 2026 |
| Resinwoodshop Ltd | Wholesale & retail | 2025 |
| Resistance Entertainment Limited | Information & communication | 2005 |
| Resistronix Ltd | Wholesale & retail | 2025 |
| Reskalla Group Ltd | Financial services | 2025 |
| Reskalla Property Group Ltd | Real estate | 2026 |
| Resolute Media Ltd | Professional & scientific | 2015 |
| Resolution 247 Limited | Administrative & support | 2019 |
| Resolution at Work Limited | Administrative & support | 2010 |
| Resolve Bioenergy Ltd | Professional & scientific | 2019 |
| Resonance Biotech Ltd | Professional & scientific | 2022 |
| Resonance Saas Ltd | Information & communication | 2025 |
| Resono Limited | Professional & scientific | 2019 |
| Resort & Home Services Ltd | Extraterritorial | 2011 |
| Resort Limited | Water & waste | 1971 |
| Resource Conversion Financial Engineering Services Ltd | Financial services | 2017 |
| Resource Conversion PLC | Water & waste | 2011 |
| Resource Efficiency Wales Limited | Administrative & support | 2006 |
| Resource Efficient Data Limited | Information & communication | 2018 |
| Resource Employment Ltd | Administrative & support | 2020 |
| Resource Limited | Administrative & support | 1990 |
| Resource One Limited | Extraterritorial | 2011 |
| Resource R1 Limited | Real estate | 2016 |
| Resource R10 Limited | Real estate | 2019 |
| Resource R11 Limited | Real estate | 2020 |
| Resource R14 Limited | Wholesale & retail | 2020 |
| Resource R15 Limited | Financial services | 2023 |
| Resource R2 Limited | Real estate | 2016 |
| Resource R3 Limited | Professional & scientific | 2016 |
| Resource R4 Limited | Real estate | 2016 |
| Resource R5 Limited | Real estate | 2017 |
| Resource R6 Limited | Real estate | 2017 |
| Resource R8 Limited | Real estate | 2010 |
| Resource R9 Limited | Real estate | 2019 |
| Resource Right Group Ltd | Administrative & support | 2019 |
| Resource Trustees Limited | Professional & scientific | 2021 |
| Resource Two Limited | Extraterritorial | 2011 |
| Resources Management U.K. Limited | Water & waste | 1986 |
| Resourcing Partnership Wales Limited | Administrative & support | 2002 |
| Resourcing Talent Ltd | Administrative & support | 2015 |
| Respection Music Ltd | Information & communication | 2024 |
| Respectoffer Limited | Real estate | 1996 |
| Respects Bereavement Services Limited | Other services | 2016 |
| Respiror Ltd | Manufacturing | 2024 |