| Regina Global Enterprises Limited | Construction | 2024 |
| Regional Land & Property Holdings Limited | Real estate | 2013 |
| Regtech Consulting Limited | Information & communication | 2023 |
| Regtech Ltd | Information & communication | 2022 |
| REH Finance Limited | Professional & scientific | 2018 |
| Reid Architects Limited | Professional & scientific | 2001 |
| Reid Design Limited | Professional & scientific | 2022 |
| Reigning Media Limited | Professional & scientific | 2025 |
| Reignite Dent Ltd | Health & social care | 2023 |
| Reis Macacos Golf Ltd | Extraterritorial | 2023 |
| Rejuvedoc Ltd | Health & social care | 2016 |
| Reka AI Ltd. | Information & communication | 2022 |
| Rekalibrate Ltd | Administrative & support | 2019 |
| Rekha Medical Services Limited | Real estate | 2018 |
| Reliable Domestic Property Limited | Real estate | 2022 |
| Reliable Electrical Supplies Limited | Wholesale & retail | 2016 |
| Reliable Mortgage Services Limited | Professional & scientific | 2019 |
| Reliable Research Limited | Professional & scientific | 2013 |
| Reliance Contract Services Ltd | Administrative & support | 2018 |
| Reliance Contracting UK Ltd | Construction | 2023 |
| Reliant QA Ltd | Information & communication | 2025 |
| Remedial Restoration (Manchester) Limited | Construction | 2017 |
| Remedy Café & Kitchen Limited | Hospitality | 2017 |
| Remel Europe Limited | Wholesale & retail | 2001 |
| Remindu Ltd | Administrative & support | 2019 |
| Remould Limited | Manufacturing | 2013 |
| Renasa Properties Limited | Financial services | 2020 |
| Renati Limited | Construction | 2011 |
| Renewx Ltd | Professional & scientific | 2012 |
| Renmak Ltd | Wholesale & retail | 2019 |
| Renovature Ltd | Administrative & support | 2026 |
| Renown Dwellings Limited | Real estate | 2021 |
| Renowned Asset Management Limited | Professional & scientific | 2017 |
| Renshaw Limited | Professional & scientific | 2008 |
| Rent an Elephant Ltd | Wholesale & retail | 2020 |
| Rentrak Holdings UK Limited | Professional & scientific | 2009 |
| Rentrak Limited | Other services | 1990 |
| Renuyu Properties Ltd | Real estate | 2023 |
| Repay Direct Limited | Other services | 2005 |
| Reperta Ltd | Information & communication | 2026 |
| Replacement Hire Cars LLP | | 2005 |
| Repligen UK Limited | Manufacturing | 2022 |
| Reputational Risk Ltd | Information & communication | 2009 |
| Requisite Variety Solutions Ltd | Information & communication | 2024 |
| RES IT Limited | Administrative & support | 2014 |
| Rescare: the Society for Children and Adults With Learning Disabilities and Their Families | Other services | 2005 |
| Rescue Angels Network UK C.I.C. | Health & social care | 2026 |
| Rescue Intellitech UK Limited | Wholesale & retail | 2023 |
| Reservaway.Com Ltd | Administrative & support | 2024 |
| Reserve a Hotel Limited | Administrative & support | 2015 |
| Reserve Travel Group Limited | Administrative & support | 2021 |
| Residentia Limited | Real estate | 2022 |
| Residentium Limited | Real estate | 2024 |
| Resin Floor Design Limited | Construction | 2024 |
| Resolve College Limited | Education | 2019 |
| Resonate Speechwriting Limited | Professional & scientific | 2015 |
| Resource Engineering Limited | Mining & quarrying | 1978 |
| Result Consult Ltd | Professional & scientific | 2021 |
| Results Based Training Limited | Arts & recreation | 2023 |
| Resupply Operations Limited | Professional & scientific | 2024 |
| Retail Finance Intelligence Limited | Professional & scientific | 2008 |
| Retailsense Limited | Manufacturing | 1993 |
| Retrocade Ltd | Wholesale & retail | 2018 |
| Reuben ASH Ltd | Professional & scientific | 2004 |
| Revenue Haus Limited | Professional & scientific | 2025 |
| Reverse Engineering Services Limited | Manufacturing | 2008 |
| Reverse Life Ltd | Wholesale & retail | 2020 |
| Reversing Resistance Limited | Health & social care | 2023 |
| Revilo Corp Limited | Real estate | 2023 |
| Revision Pro Ltd | Education | 2025 |
| Revitaderm Ltd | Health & social care | 2024 |
| Revive Card House Ltd | Wholesale & retail | 2025 |
| Revive Management Solutions Limited | Information & communication | 2011 |
| Revolution Direct Ltd | Financial services | 2012 |
| Revtec Solutions Limited | Information & communication | 2024 |
| Rexwell Development LLP | | 2018 |
| REY REY Holdings Limited | Real estate | 2020 |
| Reyman Advisory Limited | Administrative & support | 2026 |
| Reynolds Street Limited | Construction | 2023 |
| RF Premium IT Services Limited | Information & communication | 2023 |
| Rf&Sam Limited | Professional & scientific | 2021 |
| RGC Consulting Limited | Professional & scientific | 2023 |
| Rgdc INT Limited | Health & social care | 2022 |
| Rhea Estates Ltd | Real estate | 2025 |
| Rhino Cases Limited | Wholesale & retail | 2017 |
| Rhino Design Services Limited | Administrative & support | 2007 |
| Rhjd Consultancy Limited | Professional & scientific | 2022 |
| RHK IT Consultancy Limited | Information & communication | 2025 |
| Rhocious Ltd | Administrative & support | 2014 |
| RHT Consultancy Limited | Professional & scientific | 2022 |
| Rhythm in Motion Limited | Arts & recreation | 2021 |
| RI Project 1 Limited | Real estate | 2021 |
| RI Project 2 Limited | Real estate | 2021 |
| RI Project 3 Limited | Real estate | 2023 |
| Riaan Solutions Ltd | Administrative & support | 2025 |
| Ribble Valley Properties Limited | Real estate | 2023 |
| Riber Consultants Limited | Administrative & support | 2017 |
| Richard Alan Group Holdings Limited | Financial services | 2017 |
| Richard Alexander Solutions Ltd | Administrative & support | 2011 |
| Richard Beal Consulting Limited | Administrative & support | 2025 |