| RTM Business Ltd | Wholesale & retail | 2023 |
| RTN Therapies Limited | Health & social care | 2025 |
| RTP Wholesale Limited | Wholesale & retail | 2014 |
| Rttp Services Ltd | Wholesale & retail | 2019 |
| RTU Group Ltd | Wholesale & retail | 2019 |
| RU Cheng Ltd | Extraterritorial | 2014 |
| Ruban & Suja Ltd | Wholesale & retail | 2022 |
| Rubaru Ltd | Professional & scientific | 2018 |
| Rubbernecker Limited | Arts & recreation | 2016 |
| Rubbish Cleared Promptly Ltd | Water & waste | 2018 |
| Rubicon Consultancy Limited | Information & communication | 2014 |
| Rubicon Event Management Ltd | Administrative & support | 2026 |
| Rubicon Facilities Management Ltd | Administrative & support | 2015 |
| Rubicon Foods Ltd | Hospitality | 2025 |
| Rubicon Training Ltd | Administrative & support | 2014 |
| Rubicon Woodland Management Ltd | Real estate | 2025 |
| Rubicone Bidco Limited | Financial services | 2021 |
| Rubicone Finco Limited | Financial services | 2021 |
| Rubicone Midco Limited | Financial services | 2021 |
| Rubiks Formula Ltd | Other services | 2018 |
| Rubin Altman Limited | Wholesale & retail | 2022 |
| Rubin Diamond&Gold Ltd | Mining & quarrying | 2025 |
| Rubix Cubed Recycling Limited | Water & waste | 2016 |
| Rubiz Ltd | Wholesale & retail | 2026 |
| Rublez Ltd | Wholesale & retail | 2025 |
| Ruby CDM Ltd | Professional & scientific | 2025 |
| Ruby Pharmacy Limited | Wholesale & retail | 2021 |
| Ruby PUB Company Ltd | Hospitality | 2017 |
| Rubydent Limited | Health & social care | 2026 |
| Rubylicious Dance Studio CIC | Arts & recreation | 2026 |
| Rubypolly Catering Limited | Manufacturing | 2023 |
| Rubyrose Limited | Hospitality | 2005 |
| Rucewrig Limited | Manufacturing | 2023 |
| Rudar Shop Ltd | Professional & scientific | 2019 |
| Rudb Medical Ltd | Health & social care | 2022 |
| Rudeena Solutions Ltd | Administrative & support | 2021 |
| Rudolph London Commercial Investments Limited | Wholesale & retail | 2025 |
| Rudrak Soma Nitya Limited | Manufacturing | 2026 |
| Rufus George Ltd | Real estate | 2015 |
| Rufus GUY Limited | Professional & scientific | 2018 |
| Rufus Law Ltd | Information & communication | 2016 |
| Rufus Monty Ltd | Professional & scientific | 2024 |
| Rugby Escapes Ltd | Other services | 2025 |
| Rugby Jobs Limited | Administrative & support | 2024 |
| Rugby Recruitment Services Limited | Administrative & support | 1988 |
| Rugby Roofing Solutions Ltd | Construction | 2025 |
| Ruhi Ltd | Professional & scientific | 2019 |
| Ruhid Payroll & HR Services Ltd | Professional & scientific | 2022 |
| Ruichilong Business Ltd | Wholesale & retail | 2024 |
| Ruida Limited | Hospitality | 2024 |
| Ruion Limited | Wholesale & retail | 2021 |
| Rukambs Ltd | Health & social care | 2012 |
| Rukhsana Nadeem Designer Wear Ltd | Wholesale & retail | 2011 |
| Rukomasis and Co Ltd | Wholesale & retail | 2023 |
| Ruksy's Kitchen Limited | Health & social care | 2019 |
| Rulebreakers Ltd | Hospitality | 2025 |
| RUM and Pear Ltd | Information & communication | 2025 |
| RUM Emporium Limited | Wholesale & retail | 2019 |
| RUM Hound Ltd | Wholesale & retail | 2023 |
| Rumble Media Group Limited | Professional & scientific | 2025 |
| Rume Barber Shop Limited | Other services | 2017 |
| Rumi Digital Ltd | Wholesale & retail | 2026 |
| Rumney Automotive Centre Limited | Manufacturing | 2013 |
| Rumney Care and Ambulance Service Ltd | Administrative & support | 2017 |
| Rumney Court Company Limited | Households | 1983 |
| Rumney Endodontics Ltd | Health & social care | 2023 |
| Rumney Endodontics Property Ltd | Other services | 2023 |
| Rumney Fish and Chips Limited | Hospitality | 2013 |
| Rumney Hill DP Ltd | Health & social care | 2023 |
| Rumney Motor Spares Ltd | Wholesale & retail | 2009 |
| Rumney OFF Licence Limited | Wholesale & retail | 2023 |
| Rumney Pottery Limited | Manufacturing | 2002 |
| Rumney Service Centre Ltd | Wholesale & retail | 2026 |
| Rumney Shop Limited | Wholesale & retail | 2025 |
| Rumney Test and Service Centre Limited | Wholesale & retail | 2010 |
| Rumneytakeaway Limited | Hospitality | 2025 |
| Run 4 Wales Ltd. | Arts & recreation | 2012 |
| RUN254 Republic Limited | Professional & scientific | 2019 |
| Runblast Limited | Professional & scientific | 1900 |
| Runeraffle Ltd | Information & communication | 2025 |
| Runestone Group Ltd | Wholesale & retail | 2025 |
| Runexfly Ltd | Wholesale & retail | 2022 |
| Runhedi Trading Limited | Wholesale & retail | 2023 |
| Runicon Ltd | Wholesale & retail | 2026 |
| Runnerock Co., Ltd | Extraterritorial | 2021 |
| Running Cliche Limited | Information & communication | 2022 |
| Running Home Trading Limited | Wholesale & retail | 2020 |
| Running Snail Limited | Agriculture & fishing | 2021 |
| Runrec Ltd | Administrative & support | 2013 |
| Runtz Versātilis Ltd | Manufacturing | 2025 |
| Ruodnl Limited | Wholesale & retail | 2021 |
| Ruperra Castle Equestrian & Holdings Limited | Agriculture & fishing | 2023 |
| Ruperra Castle Preservation Trust | Administrative & support | 2008 |
| Ruperra Countryside Services CIC | Agriculture & fishing | 2011 |
| Ruperra Holdings Limited | Construction | 2019 |
| Rural Skills Centre Limited | Agriculture & fishing | 2018 |
| Ruralsky Limited | Hospitality | 2005 |
| Rusgold Manufacturing Ltd | Manufacturing | 2022 |
| Rush (Central) Limited | Real estate | 2007 |
| Rush Hour Trading Limited | Wholesale & retail | 2021 |