| Rees IT Solutions Limited | Education | 2013 |
| Refreshing Supplies Limited | Wholesale & retail | 2007 |
| Regal Properties Limited | Professional & scientific | 1999 |
| Regal Rental Limited | Real estate | 2021 |
| Regatta Court Residents Association Limited(The) | Real estate | 1984 |
| Regency House Studios (Bedford) Limited | Professional & scientific | 1982 |
| Regera Properties Ltd | Real estate | 2023 |
| Regin Products Limited | Wholesale & retail | 1986 |
| Rein Auto Repair Ltd | Wholesale & retail | 2024 |
| Reliable Nursing Care Ltd | Administrative & support | 2024 |
| Remab Limited | Construction | 2022 |
| Remo COM Ltd | Transport & logistics | 2012 |
| Renaissance Trains Limited | Transport & logistics | 1997 |
| Renew Studio Limited | Professional & scientific | 2024 |
| Rent a Flat Ltd | Real estate | 2025 |
| Renting My Home Limited | Real estate | 2023 |
| Resaqua Ltd | Professional & scientific | 2021 |
| Resilient Support Services Ltd | Professional & scientific | 2026 |
| Resolve IT Solutions (Online) Ltd | Information & communication | 2013 |
| Restyle Garden & Home Ltd | Administrative & support | 2025 |
| Revconnect Ltd | Information & communication | 2023 |
| Reyes Healthcare Ltd | Health & social care | 2026 |
| RF Techno-Business Consulting Ltd | Professional & scientific | 2026 |
| RFS Clinical Consulting Ltd | Professional & scientific | 2022 |
| RGE Sparks Eroders | | 2005 |
| Rghv Limited | Financial services | 2018 |
| RHD Homes Ltd | Construction | 2019 |
| Rho-Eta Outreach Foundation C.I.C. | Health & social care | 2025 |
| Rhossili Brown Ltd | Real estate | 2021 |
| Richard Harris Performance Limited | Arts & recreation | 2012 |
| Richard Herrmann Associates Limited | Professional & scientific | 1992 |
| Richard Kenny Limited | Professional & scientific | 2011 |
| Richard Radcliffe Limited | Administrative & support | 2010 |
| Richardsons Property Services Ltd | Real estate | 2015 |
| Ridgebrook Partners Limited | Professional & scientific | 2015 |
| Ridsdale Pension Trustees Limited | Financial services | 2001 |
| Riello Limited | Wholesale & retail | 1976 |
| Riley Family Properties Limited | Real estate | 2016 |
| Ringhouse Developments Limited | Real estate | 1995 |
| RIP N SIP Beverages Ltd | Manufacturing | 2026 |
| Ripplexn Ltd | Administrative & support | 2021 |
| RISE21 Ltd | Real estate | 2025 |
| Rivenhall CAE Limited | Professional & scientific | 2008 |
| River View Management Company (Cambridge) Limited | Households | 2002 |
| Rivermill Properties Limited | Real estate | 1999 |
| Riverport Scaffolding Ltd | Construction | 2022 |
| Riverside (Clapham) Limited | Construction | 2011 |
| RJ Ellul Ltd | Manufacturing | 2026 |
| RJ House to Home Ltd | Construction | 2024 |
| RK Foot & Health Ltd | Health & social care | 2024 |
| Rkom Facility Services Ltd | Construction | 2018 |
| RKR Services Ltd | Professional & scientific | 2022 |
| RL Management Services Ltd | Construction | 2016 |
| RLH Solutions Limited | Professional & scientific | 2018 |
| RLM Electrical Services Limited | Construction | 2020 |
| RMK Trans Ltd | Transport & logistics | 2014 |
| RML Premises Limited | Real estate | 2016 |
| RNE Architecture Ltd | Professional & scientific | 2024 |
| RNJ Fabrications Limited | Manufacturing | 2004 |
| ROB & Co (East Anglia) Limited | Construction | 2016 |
| ROB & Co Developments Limited | Real estate | 2021 |
| ROB Maybank Consultancy Services Ltd | Wholesale & retail | 2021 |
| Roba Logistic Ltd | Transport & logistics | 2016 |
| Robert Couch Limited | Real estate | 2025 |
| Robert Gostkowski T/A Alterego UK Ltd | Transport & logistics | 2020 |
| Robert James Cambridge Limited | Construction | 2018 |
| Robert James Create Ltd | Real estate | 2022 |
| Robert James Group Limited | Construction | 2019 |
| Robert Lenton Limited | Agriculture & fishing | 1964 |
| Robert O'Connor Consultancy Services Ltd | Information & communication | 2017 |
| Robinsons Kimbolton Limited | Wholesale & retail | 2011 |
| Rockett Charles Ltd | Construction | 2020 |
| Rocketwrench Ltd | Professional & scientific | 2022 |
| ROD Mackenzie Ltd | Administrative & support | 2022 |
| Roland EVA Consulting Limited | Professional & scientific | 2020 |
| Rolling Forward Limited | Financial services | 2025 |
| RON W. DEW & SON Limited | Transport & logistics | 1975 |
| Room Genie Ltd | Extraterritorial | 2024 |
| Rope Access Rigging Ltd | Construction | 2026 |
| Rose and Cypher Properties Limited | Real estate | 2025 |
| Rose Maye Enterprises Ltd | Manufacturing | 2017 |
| Rose Meadows Management Company Limited | Real estate | 1997 |
| Roser Medical Ltd | Health & social care | 2016 |
| Rosern Estates Ltd | Energy | 2020 |
| Rosern Short Stays Limited | Hospitality | 2025 |
| Rosestar Investments Ltd | Real estate | 2024 |
| Rosstech Limited | Information & communication | 2006 |
| Rotash Power Projects Ltd | Construction | 2025 |
| Rothmere Consultants Limited | Professional & scientific | 2010 |
| Rothmere Estates Limited | Real estate | 2001 |
| Rothmere Galleries Limited | Wholesale & retail | 2008 |
| Rothmere Limited | Professional & scientific | 2019 |
| Rothmere.Com Limited | Professional & scientific | 1996 |
| Round and Round Limited | Wholesale & retail | 2015 |
| Roundhills View (Glatton) Limited | Households | 1997 |
| Roundthestore Limited | Information & communication | 2025 |
| Rowley Composites Ltd | Manufacturing | 2022 |
| ROY Sutton Limited | Construction | 2020 |
| Royal Oak Close Management Company Limited | Real estate | 2011 |
| RR Family Ltd | Education | 2021 |