| RC Plumbing&Electrical Ltd | Construction | 2026 |
| RC Power Ltd | Wholesale & retail | 2025 |
| RC Victorian Brickwork Ltd | Construction | 2018 |
| Rcbtech Ltd | Wholesale & retail | 2018 |
| RCD Electrical (Yorkshire) Limited | Construction | 2018 |
| Rcdn Property Services Limited | Construction | 2017 |
| Rch-Care Limited | Health & social care | 2021 |
| RCM Charnwood Limited | Construction | 2019 |
| RCM Dragon Parade Limited | Real estate | 2020 |
| RCM Dudley Street Limited | Real estate | 2020 |
| RCM Gedling Road Limited | Real estate | 2020 |
| RCM Linegate Limited | Real estate | 2020 |
| RCM NEO Holdco Limited | Construction | 2023 |
| RCM Ryelands Crescent Limited | Real estate | 2020 |
| RCM Trinity Chapel Limited | Real estate | 2021 |
| RCS (LH) Limited | Professional & scientific | 2010 |
| Rcwj Limited | Financial services | 2017 |
| RD Davies Limited | Health & social care | 2008 |
| RDC Design and Build Limited | Construction | 2020 |
| RDE Civil Engineering Ltd | Construction | 2023 |
| RDH Consultants Limited | Information & communication | 2011 |
| Rdje Services Ltd | Other services | 2019 |
| Rdls Land Limited | Extraterritorial | 2014 |
| RDP Cladding Ltd | Construction | 2013 |
| RDS Consultants Limited | Other services | 2018 |
| RDS Global Limited | Information & communication | 1997 |
| RDW Paving Limited | Construction | 2019 |
| RE 10 Limited | Administrative & support | 2003 |
| RE10 (London) Limited | Real estate | 2003 |
| RE10 Restructuring and Advisory Limited | Administrative & support | 1998 |
| RE4ORM Construction Limited | Construction | 2019 |
| Re:Hr Solutions Ltd | Administrative & support | 2025 |
| Reach OUT Home Care Ltd | Health & social care | 2023 |
| Reach OUT Remedy Limited | Professional & scientific | 2020 |
| Reachwise AI Limited | Information & communication | 2025 |
| Reaction Sports Limited | Arts & recreation | 2010 |
| Reactive Accounting Solutions Limited | Professional & scientific | 2014 |
| Reactive Bookkeeping Solutions Limited | Professional & scientific | 2016 |
| Reactive Plumber Ltd | Construction | 2024 |
| Readie Construction Limited | Construction | 2007 |
| Reading Space Ltd | Information & communication | 2025 |
| Ready Logistics Ltd | Transport & logistics | 2026 |
| Ready Steady Study Ltd | Professional & scientific | 2012 |
| Ready Steady Work Limited | Construction | 2014 |
| Readyroom Health Limited | Professional & scientific | 2020 |
| Readyroom Holdings UK Limited | Professional & scientific | 2020 |
| Readyroom Performance Limited | Professional & scientific | 2020 |
| Real Entertainment VJ Ltd | Hospitality | 2018 |
| Real Estate Acquisitions & Investment Ltd | Real estate | 2019 |
| Real MAN Talk Ltd | Health & social care | 2023 |
| Real Small Business Solutions Ltd | Information & communication | 2017 |
| Real World Designs Limited | Professional & scientific | 2003 |
| Realisation 1237 Limited | Professional & scientific | 1997 |
| Realisation 1243 Ltd | Construction | 2005 |
| Realisation 1244 Ltd | Real estate | 2020 |
| Realisation 1245 Ltd | Construction | 2025 |
| Realisation 1246 Ltd | Other services | 2024 |
| Realisation 1247 Ltd | Construction | 2024 |
| Realise Clean Limited | Administrative & support | 2019 |
| Realise Science Research Limited | Professional & scientific | 2026 |
| Reality Press Limited | Information & communication | 2006 |
| Realstar Limited | Hospitality | 1991 |
| Realty Northampton Limited | Construction | 2012 |
| Ream-Clean Limited | Administrative & support | 2012 |
| Rearguard Ltd | Construction | 2021 |
| Reative Limited | Information & communication | 2025 |
| Rebeck Communications Limited | Construction | 2002 |
| Rebel Collective Consulting Limited | Professional & scientific | 2018 |
| Reborn Barbers Ltd | Other services | 2024 |
| Reborn Demo Ltd | Construction | 2023 |
| Rebuilt Different Ltd | Wholesale & retail | 2025 |
| Recast Marketplace Ltd | Wholesale & retail | 2025 |
| Recon Catering Equipment Ltd | Wholesale & retail | 2024 |
| Recon Transport Ltd | Administrative & support | 2017 |
| Reconit Limited | Water & waste | 2026 |
| Recourse Collective Limited | Professional & scientific | 2025 |
| Recovermee Limited | Public administration | 2023 |
| Recruitico Limited | Administrative & support | 2018 |
| Recruitive Technology Ltd | Information & communication | 2023 |
| Recruitment 4 Care Ltd | Administrative & support | 2016 |
| Recruitment 4U Ltd | Administrative & support | 2010 |
| Recruitment Finder Ltd | Administrative & support | 2005 |
| Recruitment Traffic Limited | Professional & scientific | 2016 |
| Rectory Road (Rushden) "a" Limited | Households | 1988 |
| Rectory Road (Rushden) "B" Limited | Households | 1988 |
| Recycleless Ltd | Manufacturing | 2023 |
| Red Abington Limited | Hospitality | 2026 |
| Red Bank Limited | Extraterritorial | 2016 |
| Red Cafes Limited | Hospitality | 2010 |
| Red Chair Homes Ltd | Real estate | 2023 |
| Red COW Films Limited | Information & communication | 2018 |
| Red COW Holdings Ltd | Financial services | 2018 |
| Red DOT Electromechanical Company (Redemco) UK Limited | Wholesale & retail | 2024 |
| Red Eight Gallery Ltd | Arts & recreation | 2019 |
| Red Elephant Mentors Ltd | Professional & scientific | 2010 |
| Red Horse Associates Limited | Professional & scientific | 2016 |
| Red Horse Digital LLP | | 2016 |
| Red House Park (NO.2) Limited | Professional & scientific | 1999 |
| Red House Park Limited | Households | 1999 |
| Red Lion PP Ltd | Hospitality | 2025 |