| RB Roofing & Construction Limited | Construction | 2026 |
| RB Scout Ltd | Information & communication | 2025 |
| RB Surveyors Ltd | Real estate | 2019 |
| RB Vinyls Ltd | Extraterritorial | 2023 |
| RB2 Plumbing and Heating Ltd | Construction | 2020 |
| RB40 Ltd | Information & communication | 2018 |
| RBA Construction Consultants Limited | Administrative & support | 1996 |
| RBC Geomatics Limited | Administrative & support | 2006 |
| RBC Homes Limited | Construction | 2005 |
| RBC Motor Ltd | Wholesale & retail | 2025 |
| Rbcd Medical Ltd | Health & social care | 2026 |
| RBG Safety Services Ltd | Public administration | 2021 |
| RBJ Residential Services Limited | Health & social care | 2024 |
| RBK Haulage Ltd | Transport & logistics | 2021 |
| RBK Pipework Services Ltd | Construction | 2022 |
| Rbkf Yorkshire Ltd | Other services | 2025 |
| Rbpt Coaching Ltd | Other services | 2023 |
| RBS Food Consultancy Limited | Professional & scientific | 2011 |
| RBS IT Solutions Ltd | Information & communication | 2011 |
| RBT Consultancy Limited | Professional & scientific | 2025 |
| RBW Leeds Ltd | Professional & scientific | 2020 |
| RBW Pubs Ltd | Hospitality | 2026 |
| RC Locums Ltd | Other services | 2015 |
| RC Software Solutions Ltd | Information & communication | 2022 |
| RC Sports Promotions Limited | Arts & recreation | 2019 |
| RC Yachts Ltd | Wholesale & retail | 2025 |
| Rc/Dc Amazing Budget Rc's Ltd | Arts & recreation | 2026 |
| RCB Group Ltd | Administrative & support | 2009 |
| Rcbt Holdings Limited | Financial services | 2020 |
| RCC Health Consultancy Limited | Professional & scientific | 2002 |
| Rccb Solutions Limited | Wholesale & retail | 2017 |
| Rccg Living Praise Parish | Other services | 2018 |
| Rccg the Citadel Church LSC | Other services | 2024 |
| RCD Britannia Limited | Financial services | 2013 |
| Rcdw Ltd | Wholesale & retail | 2025 |
| RCI Limited | Construction | 2023 |
| Rcisw Limited | Construction | 2024 |
| RCJ Manufacturing Limited | Manufacturing | 2018 |
| Rckm Leisure Limited | Hospitality | 2016 |
| RCL Digital Ltd | Information & communication | 2018 |
| RCM Electrical Ltd | Construction | 2023 |
| RCM Real Estate Ltd | Real estate | 2024 |
| RCM Reporting Ltd | Other services | 2013 |
| RCM Scaffolding Services Limited | Construction | 2023 |
| Rcns Holdings Limited | Financial services | 2026 |
| RCR Bars Harrogate Ltd | Hospitality | 2019 |
| Rcsh Investments Ltd | Financial services | 2020 |
| RD Ducting Limited | Construction | 2009 |
| RD Forestry Ltd | Administrative & support | 2015 |
| RD Transport Leeds Ltd | Transport & logistics | 2019 |
| RD Zion Homecare Service Ltd | Administrative & support | 2024 |
| Rdeco Limited | Wholesale & retail | 2015 |
| RDG Associates Ltd | Administrative & support | 2021 |
| RDG Electrical & Security Ltd | Manufacturing | 2020 |
| RDG Property Holdings Limited | Real estate | 2019 |
| RDI Worldwide Limited | Professional & scientific | 2016 |
| Rdja Lighting Ltd | Construction | 2013 |
| RDK Live Ltd | Professional & scientific | 2018 |
| Rdla Investments Limited | Real estate | 2020 |
| RDM IT Limited | Information & communication | 2007 |
| RDM Properties Ltd | Real estate | 2025 |
| RDM Property Solutions Ltd | Real estate | 2023 |
| RDM Sales Ltd | Wholesale & retail | 2019 |
| RDN Consultancy Ltd | Professional & scientific | 2023 |
| RDR Systems Limited | Construction | 2012 |
| RDS Consultancy Ltd | Professional & scientific | 2023 |
| Rdsa Properties Ltd | Real estate | 2024 |
| RDX Pharma Ltd | Health & social care | 2025 |
| RDZ Autos Ltd | Wholesale & retail | 2023 |
| RE (2013) Limited | Extraterritorial | 2013 |
| RE 10 (Finance) Limited | Professional & scientific | 2003 |
| RE Design Projects Ltd | Professional & scientific | 2019 |
| RE Imagined Ltd | Professional & scientific | 2021 |
| Re-Ba Fitness Limited | Arts & recreation | 2008 |
| Re-Circle Energy Ltd | Construction | 2022 |
| Re-Envisageit Ltd | Information & communication | 2015 |
| Re-Start Creative Outreach C.I.C. | Health & social care | 2022 |
| Re:Gen Spaces Ltd | Real estate | 2025 |
| Re:Solve Alternative Provision Bristol Limited | Education | 2025 |
| Re:Solve Alternative Provision Hemel Hempstead Limited | Education | 2026 |
| Re:Solve Alternative Provision High Wycombe Limited | Education | 2025 |
| Re:Solve Alternative Provision Hillingdon Limited | Education | 2025 |
| Re:Solve Alternative Provision Swindon Limited | Education | 2025 |
| Re:Solve AP Limited | Financial services | 2025 |
| Re:Treat Retreat Limited | Arts & recreation | 2014 |
| REA Valley Tractors Limited | Manufacturing | 1984 |
| Reach 4 Solutions Limited | Financial services | 2003 |
| Reach 4 Wealth Limited | Professional & scientific | 2021 |
| Reach Aware Limited | Information & communication | 2016 |
| Reach Belvedere Limited | Construction | 2004 |
| Reach Education & Employment CIC | Education | 2026 |
| Reach Education Ltd | Administrative & support | 2007 |
| Reach Electrical Ltd | Construction | 2023 |
| Reach+ Ltd | Professional & scientific | 2025 |
| Reacs Health Care Ltd | Public administration | 2024 |
| React Electrics Limited | Construction | 2025 |
| React K9 Security Service Ltd | Administrative & support | 2020 |
| React Security Group Ltd | Administrative & support | 2003 |
| Reacta Build Limited | Professional & scientific | 2001 |
| Reaction Engines Limited | Professional & scientific | 1989 |