| Regal House Construction Limited | Construction | 2004 |
| Regen Medical Ltd | Professional & scientific | 2018 |
| Regeneration Southern Limited | Real estate | 2023 |
| Regent Court (Gloucester) Management Limited | Real estate | 2006 |
| Regent Moon Limited | Hospitality | 2020 |
| Regents Star Limited | Hospitality | 2025 |
| Regessential Limited | Professional & scientific | 2019 |
| Regione Della Campania Limited | Hospitality | 2019 |
| Regions Beyond UK | Administrative & support | 2013 |
| Rego Estates Limited | Real estate | 2025 |
| Regueira Limited | Financial services | 2011 |
| Regulatory Accounting Limited | Professional & scientific | 2015 |
| Regulatory Law (Commercial) Limited | Professional & scientific | 2024 |
| Regulatory Law Limited | Professional & scientific | 2011 |
| Regus Caring Professionals Ltd | Health & social care | 2021 |
| Rehearsal Limited | Professional & scientific | 2025 |
| Rehmati Ltd | Real estate | 2025 |
| Rehsq Limited | Professional & scientific | 2018 |
| Reilly's Paving Limited | Construction | 2016 |
| Rein and Shine Ltd | Arts & recreation | 2013 |
| Rejuvelis Clinic Ltd | Health & social care | 2026 |
| Reklaim Ltd | Professional & scientific | 2022 |
| Relative Contact Limited | Other services | 2006 |
| Relaxify Limited | Professional & scientific | 2011 |
| Release Management Associates Limited | Information & communication | 2012 |
| Reliable Care & Support Ltd | Health & social care | 2026 |
| Reliable Driveways and Construction Ltd | Construction | 2025 |
| Reliasat Limited | Professional & scientific | 2020 |
| Reliasat Space Limited | Manufacturing | 2024 |
| Relog Xpress Limited | Construction | 2023 |
| Remac Lettings Limited | Real estate | 2025 |
| Remistec Limited | Information & communication | 2017 |
| Rencorr Limited | Transport & logistics | 2010 |
| Rend Co UK Limited | Wholesale & retail | 2008 |
| Render Seller Ltd | Wholesale & retail | 2025 |
| Rendermedia Ltd | Information & communication | 2011 |
| Rendy Limited | Extraterritorial | 2019 |
| Renekton Logistics Ltd | Transport & logistics | 2019 |
| Renew Swindon CIC | Other services | 2022 |
| Renewa Volt Security Ltd | Financial services | 2025 |
| Rent N Chill Limited | Real estate | 2023 |
| Rental Dynamics Limited | Real estate | 2012 |
| Repl International Limited | Manufacturing | 1992 |
| Replica Railways Limited | Professional & scientific | 1989 |
| Required Property Solutions Ltd | Water & waste | 2020 |
| Rescue Angel Ltd | Wholesale & retail | 2025 |
| Research Health Ltd | Health & social care | 2014 |
| Reshoes Ltd | Wholesale & retail | 2019 |
| Residential Window Cleaners Limited | Other services | 2003 |
| Resido Limited | Real estate | 2025 |
| Resins-Online Limited | Extraterritorial | 2007 |
| Respiratory Care Ltd | Health & social care | 2026 |
| Respiro Health Solutions Ltd | Information & communication | 1997 |
| Respond Social Care Limited | Health & social care | 2014 |
| RESPONS24 Ltd | Administrative & support | 2018 |
| Response Heat Ltd | Construction | 2024 |
| Responsive First AID Training Ltd | Education | 2022 |
| Responsive Personnel Limited | Professional & scientific | 2014 |
| Responsive Property Management Ltd | Households | 2024 |
| RESQ365 Ltd | Information & communication | 2025 |
| Restart Technology Limited | Information & communication | 2018 |
| Restoration and Stone Ltd | Construction | 2018 |
| Restoration Roofing Limited | Construction | 2015 |
| Restrop Limited | Professional & scientific | 2017 |
| Results Rules OK Limited | Professional & scientific | 2010 |
| Resurety Ltd | Financial services | 2019 |
| Retail Action Crime KIT Limited | Information & communication | 2024 |
| Retail Lighting Design Limited | Professional & scientific | 2000 |
| Retail of Goods Ltd | Wholesale & retail | 2025 |
| Retain Property Ltd | Real estate | 2023 |
| Retain Recruitment and Consultancy Limited | Administrative & support | 2018 |
| Retain Skills Ltd | Education | 2018 |
| Retainit Education Consultancy Ltd | Education | 2024 |
| Retreats for Peace Ltd | Other services | 2025 |
| Reuben Digital Limited | Information & communication | 2016 |
| Reuben Managed Services Ltd | Information & communication | 2015 |
| Revamp Home Ltd | Construction | 2021 |
| Revivals & Restorations Ltd | Other services | 2016 |
| Revive & Refresh Ltd | Administrative & support | 2025 |
| Revive Services Limited | Health & social care | 2022 |
| Revline Limited | Real estate | 2016 |
| Revolution Performing Arts Limited | Health & social care | 2012 |
| Revolution Speciality Food Ltd | Manufacturing | 2025 |
| Revoultit Ltd | Information & communication | 2023 |
| Rexforce Limited | | 1985 |
| Rexhepi Construction Ltd | Construction | 2023 |
| Reya K Limited | Hospitality | 2019 |
| Reykyn. Limited | Other services | 2023 |
| Reynish Ecommerce Contacts Ltd | Manufacturing | 2009 |
| Reynolds Brimfield Limited | Real estate | 2021 |
| Reynolds Plumbing & Heating (Swindon) Ltd | Construction | 2022 |
| RFS Designs Ltd | Wholesale & retail | 2020 |
| Rfsignal Ltd | Information & communication | 2023 |
| RG Consulting & Solutions Ltd | Administrative & support | 2025 |
| RG Theatre LLP | | 2023 |
| RG1 CAB Ltd | Transport & logistics | 2026 |
| RGD Heating Ltd | Construction | 2026 |
| RGD Motor Ltd. | Wholesale & retail | 2020 |
| RGH & SON Builders Limited | Construction | 2020 |
| RGH New Elements Ltd | Professional & scientific | 2019 |