| R.Somasundaram Ltd | Health & social care | 2009 |
| R.Swipe Limited | Financial services | 2026 |
| RABA9 Ltd | Hospitality | 2025 |
| Racer and Rascal Ltd | Wholesale & retail | 2025 |
| Radi Investments Ltd | Construction | 2025 |
| Rado C & J Limited | Construction | 2015 |
| Radu V Services Ltd | Construction | 2023 |
| Radu-Dumitru Dragos Limited | Transport & logistics | 2016 |
| Rafay Communications Ltd | Wholesale & retail | 2014 |
| RAH Logistics Ltd | Transport & logistics | 2025 |
| Rahmati Ltd | Extraterritorial | 2018 |
| RAI Wealth Management Ltd. | Financial services | 2019 |
| Rajani Limited | Real estate | 2024 |
| Rajaratnam Properties Limited | Real estate | 2025 |
| Rajdoot RT Ruislip Ltd | Hospitality | 2023 |
| RAM & Sons Khajum Limbu Property Ltd | Real estate | 2021 |
| RAM Sita Ltd | Other services | 2024 |
| Ramaco Impex Limited | Wholesale & retail | 1982 |
| Ramana IT Consultancy UK Limited | Information & communication | 2012 |
| Randhawa Properties Portfolio Ltd | Households | 2020 |
| Range Construction Limited | Construction | 2012 |
| Rapid EYE Marketing Limited | Professional & scientific | 2004 |
| Rapid Hub Cleaners Ltd | Other services | 2021 |
| Rapid Logistics LDN Limited | Transport & logistics | 2025 |
| Rappidd Supplies Ltd | Wholesale & retail | 2019 |
| Rashmian Limited | Wholesale & retail | 1976 |
| Rasquared Investments Limited | Real estate | 2024 |
| Rassi Engineering Ltd | Wholesale & retail | 2021 |
| Rated Damp Solutions Ltd | Financial services | 2025 |
| Rated Property Development Ltd | Administrative & support | 2025 |
| Ratel Movement Diaspora Limited | Health & social care | 2026 |
| Ravenson Project Solutions Ltd | Professional & scientific | 2012 |
| RAW Performance Cars Limited | Wholesale & retail | 2026 |
| RAW Planet & Co Ltd. | Manufacturing | 2012 |
| RBM Consultancy Group Limited | Professional & scientific | 2023 |
| RC Heating and Engineering Ltd | Construction | 2022 |
| RCH International Trade Co,. Limited | Administrative & support | 2023 |
| RCM Strategy Ltd | Professional & scientific | 2021 |
| Rcube Properties Ltd | Real estate | 2016 |
| RD Management Consultancy Ltd | Professional & scientific | 2017 |
| RD Marketing Services Limited | Wholesale & retail | 2021 |
| RDB Trades Limited | Wholesale & retail | 2025 |
| Rdds Group Ltd | Real estate | 2021 |
| RDS Music Ltd | Arts & recreation | 2013 |
| RE Elite Limited | Education | 2026 |
| Re-A-Lokisa Limited | Professional & scientific | 2015 |
| Reason Development Group Ltd | Construction | 2024 |
| REB Europe Limited | Construction | 2020 |
| Reborn 22 Ltd | Administrative & support | 2022 |
| Recelera Ltd | Real estate | 2021 |
| Red Audio Post Production Limited | Information & communication | 2011 |
| Red Jaguar Marketing Ltd | Information & communication | 2020 |
| Red Lion Souvenir Ltd | Wholesale & retail | 2025 |
| Red Road Hire Ltd | Transport & logistics | 2019 |
| Red Wolf Ltd | Wholesale & retail | 2019 |
| Redandwhitemist Limited | Professional & scientific | 2020 |
| Redcroft Builders Ltd | Construction | 2019 |
| Reddy Quality Services Ltd | Manufacturing | 2019 |
| Redrock Development Group Ltd | Real estate | 2017 |
| Redroute International Limited | Information & communication | 2007 |
| Redrow Roofing Ltd | Construction | 2023 |
| Redstar London Limited | Other services | 2022 |
| Redstone Heating Ltd | Construction | 2024 |
| Reems Barber Shop Limited | Other services | 2015 |
| Refill Your CUP Limited | Wholesale & retail | 2025 |
| Reflective Space Ltd | Professional & scientific | 2021 |
| Reflex Autos Limited | Wholesale & retail | 2016 |
| Refuel Music Limited | Professional & scientific | 2010 |
| REG R US Ltd | Manufacturing | 2023 |
| Regal Car Hire Limited | Administrative & support | 2023 |
| Regalium Pharma Limited | Manufacturing | 2026 |
| Regel Services Ltd | Construction | 2019 |
| Regency Roofing & Drainage Limited | Construction | 2023 |
| Regent's Gate (Virginia Water) Management Company Limited | Households | 2025 |
| Regulatory Practice Limited | Other services | 2011 |
| Rehco Limited | Professional & scientific | 2024 |
| Reid Estates & Developments Ltd | Other services | 2022 |
| Reis Restaurants Ltd | Hospitality | 2021 |
| Reki Media Ltd | Information & communication | 2024 |
| Relax Homes Limited | Real estate | 2019 |
| Relayr Ltd | Wholesale & retail | 2026 |
| Reldas Property Ltd | Real estate | 2024 |
| Reliable Movers & Transport Ltd | Transport & logistics | 2023 |
| Relief Facilities Ltd | Education | 2024 |
| Remos Village Ltd | Administrative & support | 2019 |
| Remt Estate Ltd | Real estate | 2025 |
| Rendezvous 7 UK Ltd | Financial services | 2020 |
| Renewablesforless Ltd | Extraterritorial | 2023 |
| Renewcore Recycling Ltd | Water & waste | 2026 |
| Rent N’ Drive Ltd | Administrative & support | 2021 |
| Repairall Ltd | Real estate | 2020 |
| Resin Drives & Patios Ltd | Other services | 2020 |
| Resourcefueled Limited | Professional & scientific | 2012 |
| Restoring Life Ministries | Administrative & support | 2007 |
| Retro Redux Ltd | Administrative & support | 2024 |
| Retronovia Limited | Wholesale & retail | 2006 |
| Return Path Electrical Ltd | Construction | 2021 |
| Revaj Machinery Ltd | Wholesale & retail | 2025 |
| Revenue Experts Ltd | Other services | 2023 |
| Revenuemax Limited | Information & communication | 2026 |