| Red Zeus Limited | Administrative & support | 2011 |
| Redfort Gurkha Ltd | Hospitality | 2024 |
| Redgate Property Development Limited | Real estate | 2022 |
| Redkite Creative Productions Ltd | Professional & scientific | 2025 |
| Redoubtable Limited | Health & social care | 2017 |
| Redside Limited | Real estate | 2001 |
| REDSTINGRAY5 Ltd | Professional & scientific | 2019 |
| Reesy Limited | Wholesale & retail | 2021 |
| Reeves Contract Services Limited | Manufacturing | 2003 |
| Refactor Code Limited | Information & communication | 2015 |
| Refi Investments Ltd | Financial services | 2023 |
| Refi Ventures Ltd | Professional & scientific | 2022 |
| Refinasol Holdings Limited | Financial services | 2021 |
| Reflex Point of Sale Limited | Extraterritorial | 2015 |
| Reflex Properties LLP | | 2013 |
| Refurbishment Masterclass Limited | Education | 2016 |
| Reginald Ames Limited | Manufacturing | 1947 |
| Reinforced Deckchairs Limited | Information & communication | 1998 |
| Reinsurance Recoveries Limited | Professional & scientific | 2001 |
| Relation Limited | Professional & scientific | 2022 |
| Relf Facilities Management Ltd | Administrative & support | 2025 |
| Remount House Ltd | Construction | 2026 |
| Renair Limited | Real estate | 1967 |
| Renaissance Risk Management Limited | Professional & scientific | 2020 |
| Renegade Parts Store Ltd | Wholesale & retail | 2024 |
| Renewal Churches Trust | Other services | 2003 |
| Renia Mucha Interiors & Art Ltd | Professional & scientific | 2021 |
| Rentucky Cars Ltd | Wholesale & retail | 2020 |
| Repeatly Ltd | Information & communication | 2025 |
| Repford Consulting Limited | Real estate | 2010 |
| Repford Holdings Limited | Real estate | 2010 |
| RER POC Ltd | Transport & logistics | 2019 |
| Residential Creations Limited | Construction | 2004 |
| Respiratory Medicolegal Reports Ltd | Health & social care | 2023 |
| Response Heating Ltd | Construction | 2022 |
| Responsible Commodities Sourcing Initiative Ltd | Other services | 2012 |
| Restorguard Ltd | Administrative & support | 2013 |
| Retro Barber Shop Limited | Other services | 2014 |
| Retro Wheelz Ltd | Manufacturing | 2021 |
| Revenue Essentials Limited | Hospitality | 2009 |
| Reverend Omotola Fawehinmi Organisation Ltd | Education | 2025 |
| Review Security and IT Solutions Ltd | Information & communication | 2025 |
| Reviresco Communications LLP | | 2023 |
| Reviresco Education LLP | | 2023 |
| Reviresco Medical Ltd | Health & social care | 2026 |
| Reviresco Real Estate Ltd | Real estate | 2022 |
| Reviresco Sport LLP | | 2023 |
| Reviresco Wellbeing LLP | | 2023 |
| Revolution Energy Services Ltd | Construction | 2015 |
| Revolution Financial Limited | Administrative & support | 2015 |
| Revolution Lighting Limited | Manufacturing | 2020 |
| Revolution Technology Limited | Administrative & support | 2014 |
| REX Roofing and Building Ltd | Construction | 2026 |
| Rexam C S Pension Trustees Limited | Professional & scientific | 1971 |
| Rexam Pension Trustees Limited | Administrative & support | 1971 |
| REY Holdings Limited | Administrative & support | 2018 |
| Reyediology Ltd | Health & social care | 2024 |
| Reynolds Project Solutions Limited | Construction | 2014 |
| Rgtec Ltd. | Information & communication | 2020 |
| RH Editorial Limited | Professional & scientific | 2015 |
| RH Electrical Solutions Limited | Construction | 2017 |
| RHB Procurement Ltd | Wholesale & retail | 2023 |
| RHH Group Limited | Professional & scientific | 2017 |
| Rhino Rock LLP | | 2010 |
| Rhinobird Limited | Professional & scientific | 2017 |
| Rhoden Rehabilitation Ltd | Agriculture & fishing | 2019 |
| Rhythm 6 Capital Ltd | Information & communication | 2026 |
| Riansaar Limited | Health & social care | 2020 |
| Rice Paper Rhino Limited | Administrative & support | 2019 |
| Rich Nutrients Limited | Hospitality | 2025 |
| Richard Croucher & Co Limited | Professional & scientific | 2012 |
| Richard Drycleaners Limited | Other services | 2010 |
| Richard Piercy Professional Services Ltd | Professional & scientific | 2018 |
| Richardson Heating & Electrical Services Limited | Construction | 2003 |
| Richie Vince Entertainment Ltd | Arts & recreation | 2024 |
| Rickard Windows Ltd | Wholesale & retail | 2026 |
| Ridge Property Limited | Real estate | 2015 |
| Ridgecroft Management Company Ltd | Households | 2009 |
| Ridgemount Medical Services Limited | Health & social care | 2019 |
| Riding Farm Equestrian Centre Limited | Agriculture & fishing | 2022 |
| Riding Lane Paddock Limited | Real estate | 1998 |
| Ridinghouse Ltd | Information & communication | 2024 |
| Ridings Cafe Ltd | Hospitality | 2020 |
| Rigging Matters Limited | Arts & recreation | 2024 |
| Right Flow Plumbing Solutions Ltd | Construction | 2022 |
| Ringden Ltd | Real estate | 2026 |
| Risk and Compliance Holdings Ltd | Financial services | 2023 |
| Riskco Solutions Ltd | Real estate | 2023 |
| Risorius Search Limited | Administrative & support | 2025 |
| Rite Industrial Doors Ltd | Manufacturing | 2001 |
| Rivelin Commercial Limited | Real estate | 2021 |
| Rivelle & Leaf Company Limited | Real estate | 2025 |
| River&Wilder Ltd | Manufacturing | 2025 |
| Riverton Property Management Services Limited | Real estate | 2017 |
| Rixandmortar Ltd | Professional & scientific | 2025 |
| RJ Pepper Medical Ltd | Health & social care | 2023 |
| RJ Spray Painting Limited | Construction | 2016 |
| Rj-Bat Consulting Limited | Professional & scientific | 2023 |
| RK Architectural Services Ltd. | Construction | 2015 |
| RKC Special Projects Rainscreen & Facades Ltd | Construction | 2021 |