| Renouf Bookkeeping Services Ltd | Professional & scientific | 2011 |
| Renovation Property Trading Limited | Construction | 2026 |
| Rensonia Limited | Real estate | 2024 |
| Rent and Renovation Piesas Ltd | Construction | 2026 |
| Rent Paid Ltd | Real estate | 2022 |
| Rent Villas Algarve Limited | Hospitality | 2014 |
| Rentalsbuy Ltd | Real estate | 2017 |
| Renus Takeaway Limited | Hospitality | 2013 |
| Renzee Limited | Education | 2016 |
| Renzhi Stainless Steel Co., Ltd | Manufacturing | 2022 |
| Reome Limited | Other services | 2021 |
| Repairbox Limited | Households | 2001 |
| Repeat Experience Ltd | Information & communication | 2021 |
| Repeater Media Ltd | Professional & scientific | 2012 |
| Repel Roofing Ltd | Construction | 2023 |
| Replacer Ltd | Information & communication | 2024 |
| Repmusic Limited | Information & communication | 2014 |
| Reprap Professional Limited | Manufacturing | 2011 |
| Reproductive Healthcare Limited | Health & social care | 2000 |
| Rerizani Property Limited | Households | 2022 |
| Rescintillat Consulting Ltd | Professional & scientific | 2025 |
| Research Design UK Limited | Professional & scientific | 2022 |
| Research Research Limited | Information & communication | 1994 |
| Researchsea Limited | Information & communication | 2004 |
| Reservoir and Water Services Limited | Professional & scientific | 2018 |
| Residential Renewables Ltd | Construction | 2022 |
| Residentially LLP | | 2024 |
| Residentially Services Limited | Real estate | 2011 |
| Residentialparkhomes.Co.Uk Limited | Extraterritorial | 2020 |
| Residentialparkhomes.Com Limited | Extraterritorial | 2018 |
| Resilience Web CIC | Information & communication | 2023 |
| Resolute Audio Visual Limited | Wholesale & retail | 2023 |
| Resolution Capital (UK) Limited | Financial services | 2013 |
| Resolve Home Energy Limited | Construction | 2013 |
| Resonance Centre Global Ltd | Professional & scientific | 2019 |
| Resonate Technologies Ltd | Wholesale & retail | 2023 |
| Resonify Audio Ltd | Information & communication | 2025 |
| Resource Extraction Monitoring Organisation | Professional & scientific | 2003 |
| Respacestudio Ltd | Wholesale & retail | 2024 |
| Responsible Rentals Ltd | Real estate | 2026 |
| Resq First AID Training Ltd | Education | 2023 |
| Resseti Ltd | Professional & scientific | 2024 |
| Restaurant Twenty Two Limited | Hospitality | 2017 |
| Resu Ltd | Professional & scientific | 2025 |
| Retire Nest Limited | Real estate | 2024 |
| Reton Ring Mesh Co., Ltd | Extraterritorial | 2013 |
| Retroboe Ltd | Wholesale & retail | 2024 |
| Retrovive Limited | Construction | 2022 |
| REV Autocare Ltd | Wholesale & retail | 2025 |
| Revelare Ltd | Administrative & support | 2023 |
| Revell Carpentry Ltd | Manufacturing | 2017 |
| Revelo Business Consultants Limited | Professional & scientific | 2014 |
| Revelstoke Consulting Ltd | Professional & scientific | 2006 |
| Revicks Limited | Professional & scientific | 2025 |
| Revira Technology for Industrial Machines Co., Ltd | Wholesale & retail | 2026 |
| Revita Wellbeing Limited | Health & social care | 2019 |
| Revive Interior Renovations Limited | Other services | 2022 |
| Revive Medics Ltd | Health & social care | 2023 |
| Revive! Auto Innovations (Cambridge) Limited | Wholesale & retail | 2007 |
| Revline Auto Ltd | Wholesale & retail | 2026 |
| Revolo Biotherapeutics Limited | Professional & scientific | 2011 |
| Revolution Health & Fitness Club Limited | Arts & recreation | 2007 |
| Revolution Media & Events Ltd | Professional & scientific | 2022 |
| Revvity Discovery Limited | Professional & scientific | 2005 |
| Rewa Limited | Wholesale & retail | 2026 |
| Rexinguk Ltd | Wholesale & retail | 2022 |
| Rezolv Energy Limited | Financial services | 2022 |
| Rezylix Ltd | Information & communication | 2025 |
| RF Module and Optical Design Ltd | Manufacturing | 2004 |
| RFJ Ltd | Real estate | 2017 |
| Rftc Ltd | Health & social care | 2022 |
| Rfxcel Limited | Professional & scientific | 2018 |
| RG Duria Ltd | Health & social care | 2023 |
| RGB Electrical Services (East Anglia) Limited | Construction | 2025 |
| RGB Monolithic Limited | Manufacturing | 2018 |
| RGB Sawston Ltd | Professional & scientific | 2022 |
| Rgbloom Ltd | Wholesale & retail | 2026 |
| RHB Associates Limited | Professional & scientific | 2007 |
| RHB TM Limited | Construction | 2022 |
| Rhea Management Limited | Real estate | 2019 |
| Rhee Valley Partnership Ltd | Professional & scientific | 2025 |
| RHG Energy Advisory (UK) Limited | Mining & quarrying | 2022 |
| RHH Associates Limited | Professional & scientific | 2009 |
| Rhino Project Solutions Ltd | Extraterritorial | 2018 |
| Rhino Properties Norfolk Ltd | Real estate | 2024 |
| Rhinocorn LLP | | 2016 |
| Rhipsalis Ltd | Professional & scientific | 2020 |
| Rhizome Research Limited | Wholesale & retail | 2010 |
| Rhodes Kemp Law Ltd | Professional & scientific | 2017 |
| Rhodes Pescod Limited | Administrative & support | 2011 |
| Rhombus Systems Limited | Manufacturing | 1981 |
| Rhubarb Capital Limited | Professional & scientific | 2022 |
| Rhyming Films Ltd | Information & communication | 2019 |
| RI Zhao Sohow Shipping Marine Service Co., Limited | Extraterritorial | 2022 |
| Riboscope Ltd | Information & communication | 2022 |
| RIC Aviation Limited | Manufacturing | 2015 |
| Rich Top Trading Co., Limited | Wholesale & retail | 2022 |
| Richard Buxton Legal Services Limited | Professional & scientific | 2025 |
| Richard Buxton Trustees Limited | Professional & scientific | 2025 |
| Richard F Day Consulting Ltd | Professional & scientific | 2023 |