| RDA Rope Access Ltd | Manufacturing | 2025 |
| RDA Topco Limited | Financial services | 2024 |
| Rdmc Properties Ltd | Real estate | 2019 |
| RDP Metalwork Limited | Manufacturing | 2011 |
| RDR Services Northern Limited | Administrative & support | 2016 |
| RDT Enterprise Ltd | Administrative & support | 2024 |
| RE & BC Ltd | Real estate | 2020 |
| RE Dinner Limited | Hospitality | 2022 |
| Re-Usse Limited | Manufacturing | 2019 |
| REA Brothers Developments Limited | Real estate | 2002 |
| REA Interiors Ltd | Professional & scientific | 2024 |
| Reach Training and Coaching Limited | Education | 2010 |
| Reach Velocity Ltd | Administrative & support | 2020 |
| Reach XL Ltd | Wholesale & retail | 2024 |
| Read the Zone Limited | Information & communication | 2025 |
| Readers Specialist Tours Limited | Extraterritorial | 1987 |
| Reads Residentials Ltd | Real estate | 2024 |
| Ready Recipe Solutions Ltd | Hospitality | 2021 |
| Real Co Retreats Ltd | Health & social care | 2025 |
| Real Estate Groundworks Ltd | Construction | 2023 |
| Real Food Delivered Limited | Hospitality | 2020 |
| Real Heat Limited | Manufacturing | 2013 |
| Real Language Experience Ltd | Education | 2024 |
| Real Snowsports Limited | Administrative & support | 2014 |
| Real Soul Food Ltd | Hospitality | 2024 |
| Reallyenglish (UK) Limited | Information & communication | 2013 |
| Reallygoodthings Ltd | Information & communication | 2025 |
| Realstone Gardens Ltd | Wholesale & retail | 2018 |
| Realstone Ltd | Mining & quarrying | 2017 |
| Realtime Services Ltd | Professional & scientific | 2013 |
| Realtime Travel Services Ltd | Administrative & support | 2025 |
| Reaman Engineering Limited | Professional & scientific | 2016 |
| Reaver Tactical Ltd | Wholesale & retail | 2025 |
| Rebalance Your Life Ltd | Health & social care | 2017 |
| Rebarrel Ltd | Hospitality | 2025 |
| Rebekah Fowler Ltd | Extraterritorial | 2021 |
| Rebel Hospitality Ltd | Hospitality | 2021 |
| Reboundog Ltd | Information & communication | 2025 |
| Recall Psychology Limited | Health & social care | 2023 |
| Reclaro Limited | Professional & scientific | 2016 |
| Reconstruct Ltd | Construction | 2018 |
| Recovery College Collective Limited | Health & social care | 2017 |
| Recovery Group 961 Ltd | Transport & logistics | 2025 |
| Recovery Matters Limited | Health & social care | 2023 |
| Recovery Property London Ltd | Health & social care | 2020 |
| Recruit Reward Retain Ltd | Professional & scientific | 2022 |
| Recruiteneers Ltd | Administrative & support | 2024 |
| Recruitment Services NE Ltd | Information & communication | 2025 |
| Recseekers Limited | Administrative & support | 2024 |
| Recycle Wise Limited | Water & waste | 2025 |
| Recycling and Renewable Energy Associates Limited | Water & waste | 2003 |
| Recyke Y'Bike Ltd. | Wholesale & retail | 2006 |
| Red Biscuit Ltd | Professional & scientific | 2024 |
| Red Clover Limited | Hospitality | 2006 |
| Red COW Tavern Limited | Hospitality | 2024 |
| Red Disc Limited | Real estate | 2014 |
| Red Door Tattoo Studio Ltd | Arts & recreation | 2025 |
| Red Farm Business Services Ltd | Professional & scientific | 2013 |
| Red FOX Living Limited | Wholesale & retail | 2020 |
| Red Hall Estate Management Company Limited | Real estate | 2017 |
| Red Hall Real Estate Limited | Real estate | 2022 |
| Red Heather Experts Ltd | Professional & scientific | 2024 |
| Red Heating Solutions Ltd | Wholesale & retail | 2022 |
| Red Hope Limited | Real estate | 1982 |
| Red House Farm Management Limited | Real estate | 1992 |
| Red House Farm PUB Company Ltd | Hospitality | 2022 |
| Red I55 Ltd | Professional & scientific | 2011 |
| Red Kite Land & Property Ltd | Real estate | 2024 |
| Red Maple Consultants Ltd | Information & communication | 2006 |
| Red Momentum Management Ltd | Professional & scientific | 2017 |
| Red Nonagon Limited | Information & communication | 2016 |
| Red Olive Art Limited | Arts & recreation | 2011 |
| Red Property Solutions (UK) Ltd | Real estate | 2009 |
| Red Ridge Developments Limited | Real estate | 2000 |
| Red Ridge Residential Limited | Real estate | 2000 |
| Red Rover Interactive Limited | Information & communication | 2023 |
| Red Rover Interactive UK Limited | Information & communication | 2023 |
| Red Siren Security Ltd | Administrative & support | 2018 |
| Redbead Limited | Real estate | 2004 |
| Redbrick Rural Limited | Construction | 2007 |
| Redcar Bulk Terminal Limited | Transport & logistics | 2010 |
| Redfern Properties (Barnard Castle) Ltd | Real estate | 2021 |
| Redfern Properties Limited | Real estate | 2015 |
| Redha Consultants Ltd | Health & social care | 2024 |
| Redhead Engineering Design Ltd | Professional & scientific | 2025 |
| Redhead Roofing NE Ltd | Construction | 2022 |
| Redhead Trustee Co Ltd | Professional & scientific | 2026 |
| Redheads MAC N Cheese (Retail) Limited | Hospitality | 2024 |
| Redhouse Estate (NE) Ltd. | Real estate | 2021 |
| Redhouse Mews (Whitley Bay) Management Company Limited | Real estate | 1990 |
| Redhouse Mews 2 (Whitley Bay) Management Company Limited | Real estate | 1991 |
| Redkeygroup Ltd | Real estate | 2019 |
| Redkite Innovations Ltd | Professional & scientific | 2014 |
| Redress Group Limited | Professional & scientific | 2019 |
| Redstone Dynamics Ltd | Other services | 2024 |
| Reduce My Costs Limited | Information & communication | 2020 |
| Redwood Business Management Ltd | Administrative & support | 2017 |
| Redwood Cable Projects Limited | Information & communication | 2009 |
| Redworth Furniture Centre Limited | Wholesale & retail | 2004 |
| Reece Property Limited | Real estate | 2013 |