| R&S Repairs Ltd | Other services | 2021 |
| R&Z Metals Ltd | Water & waste | 2002 |
| R&Z Transport Ltd | Water & waste | 2002 |
| R-Jit Business Solutions Ltd | Information & communication | 2024 |
| R. Treats Limited | Hospitality | 2015 |
| R.A. Lewin Transport Limited | Transport & logistics | 2012 |
| R.E. Searby Limited | Agriculture & fishing | 1957 |
| R.E.P. Air Services Limited | Professional & scientific | 1997 |
| R.W.Gent Limited | Transport & logistics | 1968 |
| R3 LML Ltd | Transport & logistics | 2025 |
| R3V Tech Ltd | Professional & scientific | 2023 |
| R@Ffaele Limited | Real estate | 2019 |
| Race Consulting Limited | Professional & scientific | 2024 |
| Race Hub Ltd | Arts & recreation | 2015 |
| RAD Automotive Ltd | Wholesale & retail | 2023 |
| Radcliffe Management Company Limited | Households | 2020 |
| Raddleman Business Services Limited | Administrative & support | 2019 |
| Raena Stones of London Limited | Wholesale & retail | 2023 |
| Rafpol Distribution Ltd | Manufacturing | 2019 |
| Ragdale Developments Limited | Construction | 2017 |
| Rail Vision Europe Ltd | Information & communication | 2004 |
| Rainbow Engineering UK Ltd | Professional & scientific | 2015 |
| Rainbow Pizza & Kabab Limited | Hospitality | 2019 |
| Ralph Grant & SON Limited | Real estate | 1946 |
| Rand 1 Ltd | Wholesale & retail | 2025 |
| Rani's Cuisine Limited | Hospitality | 2022 |
| Rapid Engineering Limited | Manufacturing | 2007 |
| Rapid Technology Development Ltd | Professional & scientific | 2014 |
| Rapid-Res Limited | Information & communication | 2024 |
| RAR Construction Ltd | Construction | 2026 |
| Rarus Ltd | Wholesale & retail | 2011 |
| Rasio Limited | Professional & scientific | 2011 |
| Rassool Consulting Ltd | Professional & scientific | 2014 |
| Rathbone Estates Development Limited | Construction | 2017 |
| Rathod Group Ltd | Construction | 2021 |
| Ravalia Limited | Information & communication | 2013 |
| RAW & MJG Limited | Hospitality | 2023 |
| Rawfell Investments Ltd | Real estate | 2015 |
| RAY Couriers Ltd | Transport & logistics | 2024 |
| Raya Films LLP | | 2025 |
| Rayalon Filter Services (UK) Limited | Energy | 2003 |
| Raysonlee Solutions Ltd | Financial services | 2025 |
| Raywood Investments Limited | Real estate | 2026 |
| Razedge Limited | Manufacturing | 1981 |
| RB Electrical & Control Services Limited | Construction | 2024 |
| RBD Haulage Limited | Transport & logistics | 2024 |
| RBG JAK Nest Ltd | Wholesale & retail | 2024 |
| RC Renovate Ltd | Real estate | 2023 |
| RCD Holdings Limited | Financial services | 2025 |
| RDB Assets Ltd | Real estate | 2023 |
| RDB Investment Holdings Ltd | Financial services | 2024 |
| RDB Orthopaedics Ltd | Health & social care | 2019 |
| RDF Property Developments Limited | Real estate | 2008 |
| Rdfr Properties Limited | Real estate | 2024 |
| RDR Wealth Management Ltd | Financial services | 2025 |
| RDZ PR Ltd | Professional & scientific | 2009 |
| Reaching Cloud Velocity Limited | Other services | 2020 |
| Real Cable Group Limited | Professional & scientific | 2025 |
| Real Change Consulting Limited | Professional & scientific | 2025 |
| Real Easy Property Ltd | Real estate | 2023 |
| Real Solutions (Leicester) Limited | Information & communication | 1997 |
| Reality Check Management Ltd | Administrative & support | 2011 |
| Really Nice Lettings Limited | Real estate | 2020 |
| Ream App Limited | Information & communication | 2023 |
| Rean Investments Group Ltd | Professional & scientific | 2022 |
| Reap What I SEW Ltd | Manufacturing | 2025 |
| Rebeca Logistics Limited | Transport & logistics | 2019 |
| Rebecca Strudwick Jewellery Design Ltd | Manufacturing | 2022 |
| Recell Energy Bloom Developments Limited | Energy | 2022 |
| Recenergy Ltd | Administrative & support | 2021 |
| Recover Recharge Repeat Limited | Other services | 2024 |
| Recruiterweb Limited | Information & communication | 2016 |
| Recue Ltd | Professional & scientific | 2025 |
| Recwork Community Ltd | Administrative & support | 2020 |
| Recycle Centre Limited | Water & waste | 2010 |
| Recycled Engineering Components REC Ltd | Professional & scientific | 2025 |
| Red BUS Ltd | Professional & scientific | 2019 |
| Red Cat Assets Ltd | Real estate | 2025 |
| Red Eagle One Limited | Financial services | 2019 |
| Red Falcon Limited | Real estate | 2013 |
| Red House Consulting Ltd | Professional & scientific | 2011 |
| Red Infinity Ltd | Information & communication | 2019 |
| Red Lorry Ltd | Professional & scientific | 2022 |
| Red Mills (UK) | Manufacturing | 2006 |
| Red Triangle Running Ltd | Arts & recreation | 2022 |
| Red Vector Ltd | Professional & scientific | 2016 |
| RED9 Consultancy Limited | Information & communication | 2014 |
| Reda Awad Private Practice Limited | Health & social care | 2004 |
| Redcircle CNC Ltd | Professional & scientific | 2025 |
| Redemption Capital Ltd | Information & communication | 2023 |
| Redface Records Ltd | Manufacturing | 2022 |
| Redline Garage (Lboro) Ltd | Wholesale & retail | 2026 |
| Redline MOT and Repair Services Ltd | Wholesale & retail | 2026 |
| Redline Motorcycles Holdings Limited | Financial services | 2022 |
| Reed & Baum Consultants & Trainers Ltd | Real estate | 2022 |
| Reel Cinema (Global) Limited | Information & communication | 2011 |
| Reel Cinemas (Europe) Limited | Information & communication | 2011 |
| Reel Cinemas Limited | Information & communication | 1998 |
| Rees Asset Management Ltd | Real estate | 2007 |
| Rees Wealth Management Ltd | Financial services | 2019 |