| RC Hanson Consulting Ltd | Information & communication | 2023 |
| RCG Surrey Limited | Hospitality | 2019 |
| RCM Carpentry (Chobham) Ltd. | Construction | 2008 |
| RCT Land & Development Ltd | Real estate | 2026 |
| RD Sengtech Sentry Ltd | Information & communication | 2024 |
| Rdct Limited | Professional & scientific | 2026 |
| RDS 03 Ltd | Construction | 2020 |
| Reach Contact Limited | Administrative & support | 1975 |
| Reach Holdings Limited | Professional & scientific | 2007 |
| Ready Car Sales Ltd | Wholesale & retail | 2020 |
| Ready Case Limited | Manufacturing | 1981 |
| READY4RIDE Ltd | Transport & logistics | 2025 |
| Readycut UK Limited | Other services | 2012 |
| Real Chateau Limited | Administrative & support | 2022 |
| Real Design Group Ltd | Manufacturing | 2007 |
| Real Estate Evolution Limited | Construction | 1999 |
| Real Estate Investment Solutions Ltd | Professional & scientific | 2021 |
| Real Fast Club Limited | Wholesale & retail | 2018 |
| Real Touch Paris Ltd | Wholesale & retail | 2026 |
| Realand Limited | Construction | 2024 |
| Reality of Time Limited | Information & communication | 2026 |
| Realworldfundraising Ltd | Professional & scientific | 2023 |
| Reaper Enterprises Limited | Information & communication | 2000 |
| Reardon Williams Group Ltd | Health & social care | 2023 |
| Reason Factory Ltd | Information & communication | 2011 |
| Reburth Property Group Ltd | Real estate | 2024 |
| Recentrich Limited | Information & communication | 1988 |
| Rectory Assured Limited | Real estate | 1993 |
| Red EYE Print Ltd | Manufacturing | 2003 |
| Red Fashions 2024 Limited | Wholesale & retail | 2024 |
| Red Fern Innovation Ltd | Information & communication | 2016 |
| Red Lion Educational & Travel Services Limited | Education | 2025 |
| Red Lion Logistics Ltd | Transport & logistics | 2021 |
| Red MEN Media Ltd | Information & communication | 2015 |
| Red Project Management Limited | Professional & scientific | 2004 |
| Red Rulers Limited | Construction | 2017 |
| Red Sentence Limited | Administrative & support | 2014 |
| Red Squirrel Renovations Ltd | Construction | 2025 |
| Red Venus QI Ltd | Other services | 2023 |
| Redberry Living Limited | Real estate | 2015 |
| Redcurrant Jobs Ltd | Administrative & support | 2011 |
| Redeemed Christian Church of GOD Dominion Way Ltd | Other services | 2024 |
| Redfinch Court Residents Association Limited | Households | 2009 |
| Redimo Evaluators Limited | Professional & scientific | 2026 |
| Redline Performance Training Limited | Professional & scientific | 2005 |
| Redrup Plumbing & Heating Limited | Construction | 2003 |
| Redstart Strategy and Projects Ltd | Professional & scientific | 2020 |
| Redthread Advisory Ltd | Professional & scientific | 2026 |
| Redux Capital Advisers Limited | Professional & scientific | 2018 |
| Redwood Entertainment Ltd | Information & communication | 2022 |
| Redwood Financial Limited | Financial services | 2019 |
| Redwood Property Lettings Ltd | Real estate | 2025 |
| Reed LE Coutre Limited | Information & communication | 2007 |
| Reelta Holdings Ltd | Real estate | 2025 |
| Reflect Ltd | Other services | 2018 |
| Reflexion Technologies Ltd | Professional & scientific | 2024 |
| Refrigeration NO. 1 Limited | Professional & scientific | 1937 |
| Regal Guard Security Limited | Administrative & support | 2018 |
| Regene Medical Group Ltd | Health & social care | 2019 |
| Regenerate Rise & Shine CIC | Hospitality | 2026 |
| Regeneration 3 Property Limited | Construction | 2021 |
| Regnerus Consulting Limited | Administrative & support | 2013 |
| Regtrac Limited | Professional & scientific | 2018 |
| Reidy Media Limited | Education | 2010 |
| Relaydigit Limited | Information & communication | 1990 |
| Relentless Generation Ltd | Professional & scientific | 2022 |
| Reliance Ventures Limited | Real estate | 2026 |
| Relicripz Ltd | Wholesale & retail | 2026 |
| Relish Pictures Limited | Administrative & support | 2010 |
| Reload Aquarius Consultancy Services (UK) Limited | Professional & scientific | 2015 |
| REM Fire and Security Limited | Administrative & support | 2022 |
| Remap Performance Ltd | Professional & scientific | 2026 |
| Remaxbuild Ltd. | Construction | 2015 |
| Remrealty Ltd | Real estate | 2023 |
| Renaissance Capital Investments Limited | Financial services | 2025 |
| Renderhouse Limited | Wholesale & retail | 2018 |
| Reos Group Ltd | Wholesale & retail | 2022 |
| Rescue Hour Solution Ltd | Health & social care | 2017 |
| Reservation Solutions Services Limited | Administrative & support | 2016 |
| Resilixx Ltd | Information & communication | 2025 |
| Resolute Build Limited | Construction | 2025 |
| Resolute Engineering Services Limited | Construction | 1999 |
| Resoluteness Consulting Limited | Information & communication | 2026 |
| Restaurant Holdings Limited | Financial services | 2006 |
| Restoration House Limited | Health & social care | 2024 |
| Restore Official Ltd | Administrative & support | 2023 |
| Retailability Ltd | Wholesale & retail | 2026 |
| Retrofit Aero Limited | Professional & scientific | 2023 |
| Returntitle Property Management Limited | Households | 1997 |
| Reubalie Limited | Households | 2025 |
| Reva Group Limited | Professional & scientific | 2017 |
| Revbits UK & Europe Limited | Information & communication | 2021 |
| Revford Securities Limited | Financial services | 1971 |
| Revive Building Projects Ltd | Construction | 2012 |
| Revolution IT Solutions Ltd | Information & communication | 2012 |
| Revolution Realtors Ltd | Real estate | 2022 |
| Revvi Ltd | Wholesale & retail | 2015 |
| Rewok Ltd | Wholesale & retail | 2024 |
| Reynolds Freehold Ltd | Households | 2021 |
| RF Insulator Products & Services Ltd | Professional & scientific | 2006 |