| Red Brick Group Ltd | Real estate | 2023 |
| Red Chilli (Ashbourne) Ltd | Hospitality | 2013 |
| Red Chilli Indian Limited | Hospitality | 2020 |
| Red COW Allestree Ltd | Administrative & support | 2016 |
| Red Dog Leisure Limited | Arts & recreation | 2023 |
| Red DOT Creative Limited | Information & communication | 2009 |
| Red Firs Carehome Limited | Health & social care | 2013 |
| Red Herring Properties Ltd | Real estate | 2023 |
| Red Herring Smokehouses Ltd | Construction | 2021 |
| Red Horse Consulting Ltd | Administrative & support | 2017 |
| Red Hours Consulting Ltd | Information & communication | 2017 |
| Red Kite UK Limited | Professional & scientific | 2004 |
| Red Lion Repton Ltd | Hospitality | 2020 |
| Red Mountain Investments Limited | Construction | 2015 |
| Red Oaks Care Home Limited | Health & social care | 2020 |
| Red Olive Ltd | Hospitality | 2001 |
| Red Pepper Pictures Limited | Professional & scientific | 2007 |
| Red Pill Technologies Ltd | Information & communication | 2018 |
| Red RAG Project Management Ltd | Professional & scientific | 2010 |
| Red Reef Developments Limited Liability Partnership | | 2013 |
| Red Repster Limited | Real estate | 2009 |
| Red Rocks Technology Limited | Information & communication | 2022 |
| Red Rose Car Club Limited | Wholesale & retail | 2026 |
| Red Rose Foods Limited | Administrative & support | 2003 |
| Red Sea Freight Services Ltd | Transport & logistics | 2017 |
| Red Table Holdings Ltd | Real estate | 2018 |
| Red Tree PR Limited | Professional & scientific | 2013 |
| Red Tree Projects Limited | Professional & scientific | 2017 |
| Red-Print Agency Limited | Arts & recreation | 2024 |
| Red.Shoes Counselling Limited | Health & social care | 2025 |
| RED19 Creatives CIC | Education | 2026 |
| Redback Visual Limited | Professional & scientific | 2013 |
| Redberry Consultants Ltd | Information & communication | 2014 |
| Redby Limited | Construction | 2004 |
| Redcar Creative Limited | Professional & scientific | 2020 |
| Redearth Forestry Ltd | Agriculture & fishing | 2026 |
| Redefined Consult Ltd | Professional & scientific | 2024 |
| Redemption Remaps & Services Ltd | Manufacturing | 2025 |
| Redfeather Coaching Limited | Education | 2022 |
| Redfern Building Limited | Construction | 2022 |
| Redfern Tiling Solutions Ltd | Construction | 2016 |
| Redferns Estate Limited | Education | 2023 |
| Redferns Rail Services Limited | Manufacturing | 2018 |
| Redgate Serviced Offices Limited | Real estate | 2019 |
| Redhill Academy | Education | 2012 |
| Redhill MB Enterprises Limited | Real estate | 2017 |
| Redi-Lift Limited | Education | 1998 |
| Redmay Homes Limited | Real estate | 2017 |
| Redo Business Limited | Real estate | 2022 |
| Redrose Industries Limited | Wholesale & retail | 1995 |
| REDRUG2 Ltd | Professional & scientific | 2025 |
| Reds Bespoke Electrical Limited | Construction | 2026 |
| Reds Property Developments Limited | Real estate | 2014 |
| Redwood Films Limited | Arts & recreation | 2004 |
| Reececollects Ltd | Wholesale & retail | 2026 |
| Reed Family Property Investments Ltd | Real estate | 2018 |
| Reef Futures Consulting Ltd | Professional & scientific | 2020 |
| Reefcourt Limited | Real estate | 1985 |
| Reeree Services Ltd | Information & communication | 2025 |
| Reeve (Sheffield) Limited | Wholesale & retail | 2005 |
| Reeve James Property Ltd | Real estate | 2020 |
| Reeves Bricklaying Limited | Construction | 2019 |
| REF 57 Limited | Manufacturing | 2022 |
| Refine Dental Care Limited | Health & social care | 2009 |
| Refine Holdings Limited | Financial services | 2015 |
| Reflections Psychology Clinic Ltd | Health & social care | 2021 |
| Reflective Services Valet Ltd | Administrative & support | 2023 |
| Reforme Pilates Ltd | Arts & recreation | 2025 |
| Refresco Beverages UK Limited | Manufacturing | 1919 |
| Refresco Drinks UK Limited | Manufacturing | 1993 |
| Refresco Financing UK 001 Ltd | Professional & scientific | 2017 |
| Refresco Financing UK 002 Ltd | Professional & scientific | 2017 |
| Refreshing Training Company Limited | Professional & scientific | 2013 |
| Refyne Ltd | Arts & recreation | 2025 |
| Regainbelper Ltd | Arts & recreation | 2026 |
| Regal Fitness Ltd | Wholesale & retail | 2025 |
| Regal Garden Design & Landscapes Ltd | Administrative & support | 2023 |
| Regal Trade Automotive Ltd | Wholesale & retail | 2025 |
| Regal Trade Limited | Transport & logistics | 2018 |
| Regal View Management Company Limited | Households | 2020 |
| Regency East Midland Limited | Administrative & support | 2023 |
| Regency Gardens (Southwell) Management Company Limited | Households | 2016 |
| Regency Luxury Living Limited | Health & social care | 2024 |
| Regency Painting & Decorating Limited | Construction | 2013 |
| Regent Chairs Limited | Wholesale & retail | 2021 |
| Regent Cleaning Services Ltd | Administrative & support | 2026 |
| Regent Developments (Midlands) Limited | Construction | 1988 |
| Regent Living Homes Limited | Real estate | 2025 |
| Regent Street (Beeston) Management Company Limited | Households | 2015 |
| Regent Street Law Limited | Financial services | 2019 |
| Regentrecruitment Ltd | Administrative & support | 2024 |
| Regents Square (Grappenhall) Management Company Limited | Households | 2003 |
| Reggie (Long Eaton) Limited | Wholesale & retail | 2011 |
| Reggie Taylor Property Ltd | Real estate | 2025 |
| Regional Drilling Limited | Construction | 2016 |
| Regionalfx Medical Ltd | Real estate | 2017 |
| Rehab Medical Services Ltd | Health & social care | 2010 |
| Rehana Bishop Associates Limited | Health & social care | 2013 |
| Rehman & Grandsons Ltd | Information & communication | 2022 |
| Reids Motors Ltd | Manufacturing | 2025 |