| RKB Agencies Limited | Wholesale & retail | 2022 |
| Rkvst Limited | Information & communication | 2018 |
| RL & HD Pilcher Limited | Health & social care | 2013 |
| RL Huxter & Co. Limited | Professional & scientific | 2016 |
| RL Painter and Decorator Limited | Construction | 2019 |
| RLF CNC Ltd | Manufacturing | 2023 |
| Rlkb Limited | Real estate | 2016 |
| RLN Corp Ltd | Information & communication | 2012 |
| RLS Husky Ltd | Wholesale & retail | 2025 |
| Rlse Ltd | Transport & logistics | 2022 |
| RLT Holdings (UK) Limited | Professional & scientific | 2011 |
| RLW Estates Limited | Real estate | 2002 |
| RM BIO Ltd | Professional & scientific | 2021 |
| RM China Group Ltd | Wholesale & retail | 2025 |
| RM Compliance Consulting Ltd | Administrative & support | 2011 |
| RM Construction (Cambridge) Limited | Construction | 2005 |
| RM Incorporations Ltd | Financial services | 2025 |
| RM Law Limited | Professional & scientific | 2010 |
| RM Technical Services Ltd | Manufacturing | 2025 |
| RM-8 Ltd | Wholesale & retail | 2020 |
| RMC Medical Consultancy Ltd | Health & social care | 2023 |
| RMH Events Ltd | Professional & scientific | 2022 |
| RMJ Investments Ltd | Extraterritorial | 2014 |
| RML Catering Services Ltd | Hospitality | 2016 |
| RML IT Consultants Limited | Information & communication | 2004 |
| RML IT Support Limited | Information & communication | 2012 |
| RMR Capital Finance Limited | Other services | 2017 |
| RMR Capital Investments Limited | Other services | 2019 |
| RMR Capital Limited | Other services | 2013 |
| RMR Capital Properties Limited | Other services | 2015 |
| RMR Joinery Services Limited | Manufacturing | 1996 |
| RN Gametech Ltd | Information & communication | 2020 |
| Rnassist Limited | Professional & scientific | 2013 |
| Rnavate Limited | Professional & scientific | 2023 |
| RNI Consulting Ltd | Administrative & support | 2019 |
| RNS Tech Ltd | Information & communication | 2015 |
| RO Century Co., Ltd | Extraterritorial | 2020 |
| RO7E Investments Ltd | Real estate | 2023 |
| Roach Family Holdings Ltd | Professional & scientific | 2016 |
| Road House Holdings Ltd | Real estate | 2021 |
| Road Rocket Recovery Ltd | Transport & logistics | 2021 |
| Road to Amherst Limited | Professional & scientific | 2023 |
| Roadaria Tyres Ltd | Wholesale & retail | 2025 |
| Roadgauge Ltd | Information & communication | 2023 |
| Roadquest Motors Ltd | Wholesale & retail | 2025 |
| Roads Luxury Group (UK) Limited | Wholesale & retail | 2021 |
| Roairtech Ltd | Manufacturing | 2026 |
| Roamful Ltd | Manufacturing | 2024 |
| Roar Events Agency Ltd | Hospitality | 2026 |
| Roarsome Productions Ltd | Administrative & support | 2019 |
| Roarsome Storage and Staff Ltd | Administrative & support | 2024 |
| ROB Aero Ltd | Manufacturing | 2023 |
| ROB Consultant Limited | Professional & scientific | 2017 |
| ROB Hogan Engineering Ltd | Information & communication | 2017 |
| ROB Property Construction & Maintenance Ltd | Construction | 2024 |
| ROB Taxi Ltd | Transport & logistics | 2024 |
| Rob&Imogen LLP | | 2024 |
| Robara Limited | Real estate | 2017 |
| Roben Builders Limited | Construction | 2010 |
| Roben Developments Limited | Construction | 2008 |
| Robert Buttery Medical Ltd | Health & social care | 2023 |
| Robert Edwards Property Services Ltd | Construction | 2023 |
| Robert Hobbs Limited | Financial services | 2021 |
| Robert J Ltd | Wholesale & retail | 2025 |
| Robert Kicsi Ltd | Manufacturing | 2024 |
| Robert Langford Ltd | Wholesale & retail | 2004 |
| Robert Macfarlane Limited | Arts & recreation | 2020 |
| Robert Roehen Fischer Limited | Education | 2012 |
| Robert Smart Agricultural Engineers Ltd | Professional & scientific | 2012 |
| Robert.Srl Ltd | Manufacturing | 2023 |
| Roberts Properties Holdings Limited | Real estate | 2020 |
| Robey Homes Ltd | Construction | 2020 |
| Robi Finance Ltd | Financial services | 2023 |
| Robin Gardens Management Company Limited | Households | 2024 |
| Robinson College Investments 1 Limited | Administrative & support | 2013 |
| Robinson Layer LLP | | 2001 |
| Robinson Orthopaedics Limited | Health & social care | 2014 |
| Robinson Ruthenberg Limited | Health & social care | 2010 |
| Robinsons Servicing & Repairs Limited | Wholesale & retail | 2019 |
| Robinsons Worldwide Solutions Limited | Construction | 1990 |
| Robique Limited | Administrative & support | 2023 |
| Robo Ltd | Construction | 2025 |
| Robok Limited | Information & communication | 2017 |
| Robot Snail Ltd | Information & communication | 2026 |
| Robotae Limited | Professional & scientific | 2014 |
| Roboticschools Limited | Education | 2024 |
| Robs Recovery Ltd | Transport & logistics | 2022 |
| Robzydone Limited | Manufacturing | 2023 |
| Rocabella Vcpm Limited | Financial services | 2020 |
| Rocca Cambridge Limited | Hospitality | 2024 |
| Rocine Industrial Co., Ltd | Extraterritorial | 2012 |
| Rock on Clothing Ltd | Wholesale & retail | 2023 |
| Rockadolla Dogs Limited | Extraterritorial | 2022 |
| Rockies Tyre Co ., Ltd | Extraterritorial | 2014 |
| Rockingham Road Properties Limited | Real estate | 2010 |
| Rockit Realms Limited | Administrative & support | 2025 |
| Rockschild Aircraft Maintenance Ltd | Manufacturing | 2024 |
| Rockspring | Professional & scientific | 1988 |
| Rockspring Advisory Services Limited | Professional & scientific | 2008 |
| Rockspring Nominees Limited | Professional & scientific | 2006 |