| Reach Remarkable Ltd | Professional & scientific | 2012 |
| Read Insurance Brokers Limited | Professional & scientific | 2006 |
| Reading Curry House Ltd | Hospitality | 2025 |
| Reading East Amateur Boxing Club CIC | Education | 2025 |
| Reading HFS Ltd | Wholesale & retail | 2013 |
| Reading Roofing Ltd | Construction | 2026 |
| Reading Storage Solutions (Wokingham) Ltd | Other services | 2016 |
| Readings Ventures Limited | Hospitality | 2026 |
| Readypower Complete Drain Clearance Limited | Administrative & support | 1998 |
| Readypower Group Limited | Transport & logistics | 2016 |
| Readypower Rail Services Limited | Administrative & support | 1992 |
| Readypower Terrawise Limited | Construction | 2006 |
| Real DG Ltd | Professional & scientific | 2023 |
| Real Time Communications Limited | Information & communication | 2019 |
| Realdealz Ltd | Wholesale & retail | 2026 |
| Realguard Security Limited | Construction | 2020 |
| Rebasoft Limited | Information & communication | 2009 |
| Rebello Games Limited | Information & communication | 2024 |
| Reber Luke Ltd | Construction | 2025 |
| Recenso Services Limited | Information & communication | 2017 |
| Records Made Simple Limited | Administrative & support | 2018 |
| Recoverable Labs Ltd | Information & communication | 2022 |
| Recovery ME NOW Ltd | Wholesale & retail | 2025 |
| Recruit by Nature Limited | Administrative & support | 2014 |
| Rectory Lodge Management Company Limited | Real estate | 2004 |
| Rectro Ltd | Administrative & support | 2025 |
| Red Balloon Entertainment Ltd | Professional & scientific | 2025 |
| Red Beard Barbell Club Limited | Arts & recreation | 2018 |
| Red C Research Ltd | Professional & scientific | 2015 |
| Red Cedar Developments Ltd | Construction | 2022 |
| Red Cedar Homes Ltd | Real estate | 2021 |
| Red Compass Consulting Ltd | Professional & scientific | 2025 |
| Red Lion Motors Limited | Wholesale & retail | 2021 |
| Red Oak Stores Ltd | Wholesale & retail | 2018 |
| RED4LIME Ltd | Arts & recreation | 2019 |
| Redbill Properties Limited | Construction | 2005 |
| Redbrick Luggage Limited | Manufacturing | 2015 |
| Redcube Global Ltd | Information & communication | 2025 |
| Redenham Park Dental Practice Ltd | Health & social care | 2019 |
| Redgate & Redgate Limited | Information & communication | 2003 |
| Redhammer Demolition Limited | Construction | 2013 |
| Redheart UK Limited | Administrative & support | 2026 |
| Redkite Training Solutions Ltd | Administrative & support | 2014 |
| Redline Refined Ltd | Wholesale & retail | 2026 |
| Redporth Assure Limited | Professional & scientific | 2025 |
| Redporth Group Limited | Financial services | 2025 |
| Redporth Limited | Professional & scientific | 2020 |
| Redporth Resource Ltd | Administrative & support | 2023 |
| Redridge Home Improvements Ltd | Construction | 2026 |
| Redthread London Ltd | Professional & scientific | 2001 |
| Redwing Robey Ltd | Financial services | 2021 |
| REE Design Ltd | Construction | 2024 |
| Reed Homes Holdings Limited | Real estate | 2023 |
| Reeves Chase Limited | Real estate | 2017 |
| Refine: Nightingale Aesthetics Company Ltd | Health & social care | 2020 |
| Reflection Training Ltd | Wholesale & retail | 2020 |
| Refresh Barbers Ltd | Other services | 2024 |
| Refresh Head Quarters Ltd | Arts & recreation | 2025 |
| Regatta Court Management Company Limited | Households | 1999 |
| Regents Court (Newbury) Management Limited | Households | 1988 |
| Reggie Hinton Hire Ltd | Administrative & support | 2018 |
| Regroup Pharma Ltd | Administrative & support | 2024 |
| Reineke Property Company Ltd | Real estate | 2025 |
| Reineke Watch Company Ltd | Manufacturing | 2023 |
| Relationship Matters Ltd | Extraterritorial | 2016 |
| Reliance Energy (LN) Limited | Administrative & support | 2016 |
| Rely-Tech Consultancy Ltd | Information & communication | 2015 |
| Remaking Ltd | Arts & recreation | 2012 |
| Remedi Extracts Ltd | Wholesale & retail | 2025 |
| REN Decorating Limited | Construction | 2020 |
| Renascence Group Ltd | Professional & scientific | 2005 |
| Rendered Ltd | Administrative & support | 2026 |
| Renew Health and Wellness Ltd | Health & social care | 2023 |
| Renewable Land Resources Limited | Administrative & support | 2016 |
| Requiem Law Ltd | Professional & scientific | 2023 |
| Requisit Consultancy Limited | Information & communication | 2017 |
| Research in Focus Limited | Professional & scientific | 2013 |
| Resolve Resources Limited | Administrative & support | 2019 |
| Resource Experience Limited | Professional & scientific | 1995 |
| Responsichain Limited | Information & communication | 2024 |
| Resto Coachtrimming Ltd | Wholesale & retail | 2024 |
| Restore Roofing Ltd | Construction | 2026 |
| Resurgence Gear UK Ltd | Wholesale & retail | 2015 |
| Resurgence Limited | Information & communication | 2015 |
| Resurv Limited | Information & communication | 2004 |
| Retail Active Limited | Administrative & support | 2000 |
| Rethink Packaging Ltd | Professional & scientific | 2006 |
| Retro Motive Ltd | Manufacturing | 2022 |
| Review Revive AI Ltd | Professional & scientific | 2026 |
| Revive Customs Ltd | Wholesale & retail | 2013 |
| Revive Restore & Repair Limited | Other services | 2024 |
| Revivox Limited | Wholesale & retail | 2026 |
| Revolute Ltd | Public administration | 2025 |
| Revolution Development UK Ltd | Information & communication | 2022 |
| Revving Limited | Other services | 2020 |
| Revyo Limited | Hospitality | 2025 |
| Rewo Electrical Ltd | Construction | 2026 |
| Rexxol Limited | Wholesale & retail | 2011 |
| Reynolds Wood Limited | Professional & scientific | 2014 |
| Rezone Ltd | Information & communication | 2025 |