| Red FOX Analysis Limited | Information & communication | 2018 |
| Red FOX Cyber & IA Limited | Information & communication | 2018 |
| Red Freckle Limited | Administrative & support | 2010 |
| Red Hot Chilli Northwest Limited | Wholesale & retail | 2005 |
| Red House Legal Limited | Professional & scientific | 2017 |
| Red House Properties (NW) Ltd | Real estate | 2025 |
| Red Isle Solutions Ltd | Professional & scientific | 2015 |
| Red Kite Clinical Limited | Administrative & support | 2024 |
| Red Kite Engineering Ltd | Administrative & support | 2023 |
| Red Kite Technology Projects Ltd. | Administrative & support | 2007 |
| Red Leaf Interiors Ltd | Other services | 2021 |
| Red Nori Bidco 1 Limited | Financial services | 2025 |
| Red Nori Limited | Financial services | 2025 |
| Red Nori SPV 1 Limited | Financial services | 2025 |
| Red Nori SPV 2 Limited | Financial services | 2026 |
| Red OR Blue Rooms 4 U Ltd | Real estate | 2025 |
| Red Panel Products Limited | Manufacturing | 2018 |
| Red Pumpkin Ltd | Professional & scientific | 2022 |
| Red Robin Property Letting and Management Ltd | Real estate | 2026 |
| Red Rock Facilities Management Limited | Administrative & support | 2013 |
| Red Rock Properties Ltd | Extraterritorial | 2013 |
| Red Rose Infrastructure Limited | Financial services | 2011 |
| Red Rose Rise Limited | Hospitality | 2023 |
| Red Security Solutions Limited | Administrative & support | 2012 |
| Red Tarn Racking Limited | Construction | 2007 |
| Red Web Digital Ltd | Information & communication | 2026 |
| Red Wrenn Education Limited | Administrative & support | 2022 |
| RED032 Ltd | Professional & scientific | 2007 |
| RED7 Projects Ltd | Professional & scientific | 2024 |
| Redacre Consulting Ltd | Professional & scientific | 2009 |
| Redacre Energy Associates Ltd | Professional & scientific | 2019 |
| Reddy Enterprise Limited | Households | 2021 |
| Reddy Learning & Development Limited | Professional & scientific | 2017 |
| Redecorate Ltd | Construction | 2026 |
| Redes Remote Engineering Design Services Limited | Professional & scientific | 2019 |
| Redfern Construction Management Limited | Construction | 2017 |
| Redfern Group Consulting Ltd | Professional & scientific | 2023 |
| Redfox Technology Limited | Administrative & support | 2008 |
| Redkoala Solutions Ltd | Information & communication | 2013 |
| Redlane (North West) Limited | Construction | 2018 |
| Redline Automotive Ltd | Wholesale & retail | 2019 |
| Redline Corp Holdings Limited | Financial services | 2024 |
| Redline Safety Ltd | Professional & scientific | 2020 |
| Redline Services Ltd | Professional & scientific | 2023 |
| Redmill Gardens Residents Management Company Limited | Households | 2026 |
| Redo Creative Ltd | Information & communication | 2024 |
| Redorr Heating and Cooling Services Ltd | Construction | 2025 |
| Redpeak Ventures Ltd | Hospitality | 2025 |
| Reds Fitness CIC | Public administration | 2019 |
| Redsky Power Limited | Manufacturing | 2014 |
| Redstone Rentals Limited | Real estate | 2025 |
| Redstone Strategic Partners LLP | | 2026 |
| Redtrail Limited | Extraterritorial | 2008 |
| Redtree Logistics Ltd | Transport & logistics | 2019 |
| Reduced Ligature Services Ltd | Professional & scientific | 2023 |
| Redzvision Security Limited | Administrative & support | 2022 |
| Reece Ackers Property Services Ltd | Real estate | 2023 |
| Reece Duncan Limited | Administrative & support | 2026 |
| Reenterprises Ltd | Wholesale & retail | 2023 |
| Rees Engineering Design Services Limited | Administrative & support | 2011 |
| Rees Environmental Ltd | Professional & scientific | 2011 |
| Refine Homewares Ltd | Wholesale & retail | 2025 |
| Refined Consultancy Limited | Administrative & support | 2014 |
| Refined Residences Ltd | Real estate | 2025 |
| Refinetex Limited | Manufacturing | 2025 |
| Reflex Courier Ltd | Transport & logistics | 2000 |
| Reflex Express Limited | Professional & scientific | 2005 |
| Reformix Consulting Ltd | Professional & scientific | 2026 |
| Reframe Education Ltd | Professional & scientific | 2024 |
| Refresh Mortgage Network Limited | Other services | 2018 |
| Refrigerant Gases (UK) Ltd | Extraterritorial | 2010 |
| Refrigerant Gases Ltd | Wholesale & retail | 2010 |
| Refuel & Recharge Ltd | Hospitality | 2025 |
| Refurban Limited | Construction | 2021 |
| Regaffairs Consulting Ltd | Professional & scientific | 2024 |
| Regal Cheshire Careprop Ltd | Real estate | 2025 |
| Regal Cheshire Investment Partners Ltd | Financial services | 2025 |
| Regal Cheshire Propco Ltd | Real estate | 2025 |
| Regal Commercial Property Investments Limited | Real estate | 2026 |
| Regal Compliance Ltd | Professional & scientific | 2017 |
| Regal Crown Holdings Limited | Financial services | 2024 |
| Regal Crown Logistics Limited | Other services | 1993 |
| Regal Crown Pacific Lines Limited | Other services | 1995 |
| Regency Glass Limited | Manufacturing | 2006 |
| Regency Nannies Limited | Administrative & support | 1996 |
| Regent Solutions Ltd | Information & communication | 2026 |
| Regent Street Investments Limited | Real estate | 2021 |
| Regenthaus Property Group Ltd | Hospitality | 2025 |
| Rehomy Ltd | Professional & scientific | 2022 |
| Reimagine Therapy Ltd | Health & social care | 2019 |
| Reiwa Limited | Real estate | 2021 |
| REJ Project Management Limited | Administrative & support | 2024 |
| Relax Private Barbering Studio Ltd | Other services | 2026 |
| Relay Systems Limited | Manufacturing | 2019 |
| Releasing My Potential Limited | Administrative & support | 2018 |
| Reliability Maintenance Solutions Limited | Professional & scientific | 1999 |
| Reliable Generation Ltd | Energy | 2016 |
| Reliable Manufacturing Limited | Professional & scientific | 2001 |
| Reliant Plumbing & Heating Ltd | Construction | 2023 |
| Reliaopt Ltd | Professional & scientific | 2023 |