| Red ANT Ltd | Construction | 2025 |
| Red Cylinder Ltd | Wholesale & retail | 2026 |
| Red Door Research Ltd | Professional & scientific | 2013 |
| Red Douc Limited | Information & communication | 2007 |
| Red Root Pictures Ltd | Information & communication | 2022 |
| Redbridge Capital Limited | Financial services | 2025 |
| Redges-Of-London Ltd | Wholesale & retail | 2021 |
| Redmaran Properties Limited | Real estate | 2026 |
| Redwood Carpentry Ltd | Construction | 2025 |
| Reece AI Ltd | Information & communication | 2026 |
| Reel Frames Creative Ltd | Information & communication | 2025 |
| Refiner's Flame Ltd | Wholesale & retail | 2026 |
| Regelous Media Consulting Ltd | Extraterritorial | 2023 |
| Regency Brides Limited | Wholesale & retail | 2017 |
| Reggiecom Ltd | Information & communication | 2002 |
| Reggie’S Place Limited | Administrative & support | 2021 |
| Regional Developments Limited | Construction | 2014 |
| Reign Consulting Ltd | Professional & scientific | 2022 |
| Reis Estates Ltd | Real estate | 2026 |
| Reliable Repair Crew Ltd | Construction | 2024 |
| Remax Maintenance Ltd | Construction | 2023 |
| Remedy Therapy and Coaching Ltd | Health & social care | 2025 |
| Remix London Limited | Wholesale & retail | 2017 |
| Renatus Consulting Limited | Professional & scientific | 2012 |
| Rendezvous Properties Limited | Construction | 2019 |
| Renee Parris Limited | Manufacturing | 2009 |
| Renegade Wellness Limited | Health & social care | 2023 |
| Renel Limited | Health & social care | 2004 |
| Rentr Check Ltd | Administrative & support | 2026 |
| Repair Restore Rebuild Limited | Professional & scientific | 1998 |
| Resin Bound London Ltd | Construction | 2024 |
| Resolute Medicare Ltd | Health & social care | 2022 |
| Resourcing Risk Ltd | Real estate | 2004 |
| Retail Fifty Two Ltd | Professional & scientific | 2022 |
| RETURN2PLAY Ltd | Administrative & support | 2015 |
| Revive Croydon CIC | Construction | 2026 |
| Reward 2 Ltd | Other services | 2018 |
| Reya Catering Ltd | Hospitality | 2024 |
| Rezkhiz Ltd | Real estate | 2022 |
| RG Sound Solutions Limited | Administrative & support | 2018 |
| Rhoden Transportation Solutions Ltd | Transport & logistics | 2019 |
| Rhone Associates Limited | Health & social care | 2007 |
| RHS Projects Limited | Real estate | 2021 |
| RHS Services Ltd | Transport & logistics | 2019 |
| Rhss Limited | Professional & scientific | 2007 |
| RIC Rendel Limited | Health & social care | 2024 |
| Ricdip Software Solution Ltd | Information & communication | 2018 |
| Richards-Invest Ltd | Real estate | 2021 |
| Richeducation Ltd | Education | 2025 |
| Richina Limited | Administrative & support | 2009 |
| Richina Trading Limited | Wholesale & retail | 2020 |
| Richmond Accountants Ltd | Professional & scientific | 2016 |
| Riddleah C RTM Company Limited | Households | 2025 |
| Ridgestone Ltd | Real estate | 2024 |
| Ridhkrish Property Limited | Real estate | 2025 |
| Riem Johnson Limited | Health & social care | 2020 |
| Right Quality Ltd | Wholesale & retail | 2012 |
| Risked Return Ltd | Professional & scientific | 2022 |
| Riverbourne Estates Limited | Real estate | 2010 |
| Riverbourne Financial Solutions Limited | Financial services | 2010 |
| Riviera Paris Limited | Wholesale & retail | 2019 |
| Rizzydetailz Ltd | Administrative & support | 2026 |
| RJ 777 Limited | Health & social care | 2016 |
| RJA Construction & Renovation Limited | Construction | 2013 |
| RJD Contractor Services Ltd | Financial services | 2026 |
| RJL Mechanical Ltd | Construction | 2023 |
| Rman Global Ltd | Real estate | 2015 |
| Rmgss Limited | Information & communication | 2013 |
| RMK Brother's Limited | Real estate | 2020 |
| RNB Construction & Roofing Ltd | Construction | 2024 |
| ROB Ricketts Studio Ltd | Professional & scientific | 2023 |
| Robert Nibbs Limited | Manufacturing | 2012 |
| Roberts Design Associates Ltd | Arts & recreation | 2015 |
| Robertson's Colour - Photography X Fashion Ltd | Professional & scientific | 2024 |
| Robust AE Ltd | Construction | 2018 |
| Rochelles Maintenance Ltd | Administrative & support | 2013 |
| Rockie Ltd | Information & communication | 2026 |
| Rocklands Drive Management Company Limited | Real estate | 2010 |
| Rocksalt Investments Limited | Real estate | 2021 |
| Rocksys Ltd | Information & communication | 2011 |
| Rocla Ltd | Wholesale & retail | 2023 |
| Rodasan Solutions Limited | Information & communication | 2013 |
| Rolled Sleeves Ltd | Professional & scientific | 2018 |
| Roman Catering Limited | Hospitality | 2019 |
| Romark Projects Managment Limited | Construction | 2017 |
| Rons Vending Ltd | Wholesale & retail | 2026 |
| Rontas Limited | Other services | 2019 |
| Rood Property Ltd | Real estate | 2024 |
| Rootfloe Ltd | Information & communication | 2017 |
| Rootstack Ltd | Information & communication | 2024 |
| Rope Access Dynamics Ltd | Construction | 2025 |
| Roscoe Ventures Limited | Real estate | 2017 |
| Rosebuds UK Services Limited | Administrative & support | 2024 |
| Rosedecor & Developments Limited | Construction | 2010 |
| Rosehill Cafe Carshalton Limited | Hospitality | 2018 |
| Rosetta IT Consulting Ltd | Information & communication | 2025 |
| Roseweir Limited | Real estate | 2021 |
| Rossco & Sons Limited | Construction | 2025 |
| Rossiter Films Ltd | Arts & recreation | 2025 |
| Rothesay Property Partners Ltd | Real estate | 2025 |