| Rehman & Sons Properties Limited | Real estate | 2024 |
| Rehoboth Cleaning & Facility Management Ltd | Administrative & support | 2026 |
| Rehoboth Technology Services Ltd | Professional & scientific | 2018 |
| Rehsye Ltd | Health & social care | 2024 |
| Reifam Limited | Construction | 2014 |
| Reign and Aayah Ltd | Wholesale & retail | 2022 |
| Reign Residences Ltd | Real estate | 2024 |
| Reis Electrical Ltd | Construction | 2021 |
| Rejo's UK Ltd | Wholesale & retail | 2021 |
| Rejuiced Liquids Limited | Manufacturing | 2016 |
| REL Building Contractors Ltd | Construction | 2019 |
| Rela Consultants Ltd | Real estate | 2022 |
| Rela Support Services Ltd | Health & social care | 2009 |
| Relane Corporation Limited | Professional & scientific | 2016 |
| Releaf Energy Ltd | Construction | 2025 |
| Reliable Environmental Ltd | Water & waste | 2013 |
| Reliable Utility Consulting Ltd | Professional & scientific | 2026 |
| Reliance Enterprises UK Limited | Education | 1999 |
| Reliance Nationwide Services Ltd | Administrative & support | 2019 |
| Reliance UK Care Ltd | Health & social care | 2023 |
| Reliancemove Ltd | Transport & logistics | 2025 |
| Reliant Commerce Limited | Wholesale & retail | 2025 |
| Reliant Ventures Limited | Information & communication | 2023 |
| Relicstone Limited | Professional & scientific | 2013 |
| REM Supreme Construction Ltd | Construction | 2023 |
| Remand by Arch Ltd | Education | 2025 |
| Remark Trends Ltd | Wholesale & retail | 2019 |
| Remco Executive Ltd | Transport & logistics | 2014 |
| Remedy Tea Rooms UK Limited | Hospitality | 2026 |
| Remedy Teas Ltd | Hospitality | 2022 |
| Remember Productions Limited | Arts & recreation | 2024 |
| Remexpress Limited | Hospitality | 2020 |
| Remi Enterprise Ltd | Wholesale & retail | 2017 |
| Remiah Digital Ltd | Professional & scientific | 2021 |
| Remman Ltd | Hospitality | 2017 |
| Remote Hire Group Ltd | Administrative & support | 2023 |
| Remote Run Ltd | Information & communication | 2025 |
| Remotlys London Ltd | Financial services | 2025 |
| Remotlys Property Holding Limited | Financial services | 2025 |
| Remotlys.Com Limited | Hospitality | 2023 |
| Removaltree Ltd | Transport & logistics | 2016 |
| REN Therapeutics Ltd | Manufacturing | 2024 |
| Renaissance Coffee Limited | Hospitality | 2026 |
| Renava Ltd | Real estate | 2022 |
| Rendmaster Limited | Wholesale & retail | 2021 |
| Rendol Limited | Construction | 2010 |
| Rene Muyot Properties Limited | Real estate | 2021 |
| Renee Clothing Ltd | Wholesale & retail | 2022 |
| Renegade Trading Ltd | Wholesale & retail | 2024 |
| Renkler Ltd | Other services | 2015 |
| Renowise Limited | Administrative & support | 2020 |
| Rent a Garden Space Ltd | Arts & recreation | 2025 |
| Rentman Limited | Financial services | 2021 |
| Rentman Software Limited | Information & communication | 2003 |
| Rentnest Limited | Real estate | 2020 |
| Rentprops Ltd | Real estate | 2026 |
| Renu Heat 2010 Ltd | Construction | 2025 |
| Renua Ltd | Construction | 2024 |
| Renwangit Limited | Health & social care | 2018 |
| REP Manufacturing Limited | Manufacturing | 2001 |
| REP33 Ltd | Professional & scientific | 2021 |
| Repair Crew Limited | Manufacturing | 2025 |
| Resear-Ligent Limited | Information & communication | 2022 |
| Resi Auto Sales Ltd | Wholesale & retail | 2024 |
| Resin Art Supplies UK Limited | Wholesale & retail | 2021 |
| Resin Dreams Ltd | Professional & scientific | 2026 |
| Resolute Carpentry Ltd | Manufacturing | 2021 |
| Resonance Diagnostics Limited | Health & social care | 2019 |
| Resound Training and Development Ltd | Administrative & support | 2004 |
| Resource Facilities Management Ltd | Administrative & support | 2024 |
| Resourcingdirect Group Ltd | Professional & scientific | 2024 |
| Resourz Group Ltd | Construction | 2024 |
| Respect Digital Limited | Information & communication | 2020 |
| Respite Medicals Ltd | Extraterritorial | 2011 |
| Response Electrical Services Limited | Construction | 2011 |
| Response Repro Limited | Administrative & support | 2002 |
| Responsible Focus Ltd | Construction | 2019 |
| Rest Ltd | Real estate | 2021 |
| Rester Limited | Hospitality | 2023 |
| Resting Home Limited | Real estate | 2024 |
| Restockers Ltd | Wholesale & retail | 2025 |
| RESTORE2HEALTH Ltd | Health & social care | 2025 |
| Restoring Crowns CIC | Education | 2025 |
| Resurrection Life Centre Ltd | Education | 2009 |
| Retail Gateway Limited | Administrative & support | 2001 |
| Retail Homeware Limited | Wholesale & retail | 2021 |
| Retail Sales Ltd | Wholesale & retail | 2021 |
| Retford Properties Limited | Real estate | 2021 |
| Retro Gaming Ltd | Other services | 2017 |
| Retro Giant Ltd | Wholesale & retail | 2018 |
| Retro Kick OFF Ltd | Wholesale & retail | 2025 |
| Retrocore Ltd | Information & communication | 2025 |
| Retrofit Assessor Group Ltd | Construction | 2024 |
| Retrospect Property Solutions Ltd | Construction | 2023 |
| Revarex Limited | Information & communication | 2020 |
| Revex Recovery Ltd | Other services | 2008 |
| Revised Nutri Ltd | Health & social care | 2019 |
| Revival Studios Wellness Ltd | Other services | 2025 |
| Revive and Shine Aesthetics Ltd | Other services | 2025 |
| Revived Developments Limited | Construction | 2025 |