| Regentry Limited | Administrative & support | 2019 |
| Regional Safety Group Limited | Administrative & support | 2021 |
| Reid Environmental Limited | Real estate | 2025 |
| Reilly Painters and Decorators Ltd | Construction | 2017 |
| Reimes Properties Ltd | Real estate | 2022 |
| Relaxity Ltd | Education | 2022 |
| Relfe & Co Limited | Administrative & support | 2018 |
| Reliable Grounds & Garden Maintenance Limited | Administrative & support | 2001 |
| Remarkabull Marketing Limited | Information & communication | 2026 |
| Remember Them Limited | Extraterritorial | 2009 |
| Remnant Services Ltd | Manufacturing | 2022 |
| Remote Engineering Consultancy Limited | Professional & scientific | 2021 |
| Renfields Tech Ltd | Information & communication | 2025 |
| Renovation Limited | Construction | 2003 |
| Renuka IT Limited | Professional & scientific | 2018 |
| Renvyle Bioservices Ltd | Professional & scientific | 2023 |
| RER Expert Witness Services Ltd | Professional & scientific | 2022 |
| RES Education Ltd | Education | 2022 |
| Research Development and Strategy Consulting Limited | Professional & scientific | 2023 |
| Resilience and Continuity Consulting Limited | Professional & scientific | 2023 |
| Resilient Partners Ltd | Professional & scientific | 2017 |
| Resolve Events Ltd | Arts & recreation | 2025 |
| Resonant Recruitment Development Ltd | Administrative & support | 2021 |
| Restless Pictures Limited | Arts & recreation | 2019 |
| Resultsiq Limited | Professional & scientific | 2023 |
| Reveal Events Limited | Arts & recreation | 2024 |
| Revere Competitions Ltd | Wholesale & retail | 2023 |
| Revert Sports Ltd | Wholesale & retail | 2021 |
| Revive Accountancy & Tax Services Ltd | Professional & scientific | 2024 |
| Revxops Ltd | Information & communication | 2025 |
| Rewilding Opportunities Limited | Agriculture & fishing | 2021 |
| Rezonic API Ltd | Information & communication | 2026 |
| Rfid Technology Limited | Information & communication | 2024 |
| RG Fire Services Ltd | Public administration | 2025 |
| RG27 Limited | Wholesale & retail | 2015 |
| RGP Pension Services Limited | Professional & scientific | 2015 |
| RGP Project Solutions Ltd | Administrative & support | 2007 |
| RH Coaching Ltd | Professional & scientific | 2020 |
| RH Home Improvements Limited | Construction | 2012 |
| RH Sixteen Electrical Ltd | Construction | 2026 |
| RH16 Meeting Rooms Ltd | Administrative & support | 2025 |
| Rhiannon Newman Brown Ltd | Professional & scientific | 2018 |
| Ribbon Consulting Ltd | Administrative & support | 2016 |
| RIC Props Ltd | Information & communication | 2025 |
| Rich Clinical Services Limited | Administrative & support | 2011 |
| Rich Hurley Limited | Professional & scientific | 2024 |
| Richard M Toms Limited | Construction | 2018 |
| Richard Payne Ltd | Information & communication | 2019 |
| Rickety Software Ltd | Information & communication | 2025 |
| Ricky Gache Farriers Limited | Other services | 2010 |
| Ridge & Shore Holdings Ltd | Real estate | 2026 |
| Ridiculous Corporation Limited | Manufacturing | 2025 |
| Rights of MAN (Lewes) Ltd | Hospitality | 2014 |
| Ringo Wearables Limited | Wholesale & retail | 2026 |
| RIO Davies Limited | Professional & scientific | 2025 |
| Rippon Solutions Limited | Professional & scientific | 2017 |
| Rise Together Consulting Limited | Professional & scientific | 2025 |
| Rise Wellbeing Studios Ltd | Other services | 2025 |
| Rising GEN Ltd | Professional & scientific | 2023 |
| Risk Quilt Ltd | Information & communication | 2026 |
| River 26 Ltd | Real estate | 2019 |
| Riverpeak Holdings Limited | Financial services | 2013 |
| Riverpeak Wealth Limited | Financial services | 2013 |
| Riverside (Lewes) Limited | Administrative & support | 1991 |
| RJS Electrochanical Engineering Services Ltd | Construction | 2009 |
| Rk(Eastbourne) Ltd | Wholesale & retail | 2025 |
| Rk(Haywards) Ltd | Wholesale & retail | 2025 |
| Rk(Horsham) Ltd | Wholesale & retail | 2025 |
| Rk(Lewes) Ltd | Wholesale & retail | 2025 |
| RLD Automation Limited | Professional & scientific | 2018 |
| RM Coastguard Limited | Real estate | 2025 |
| RM Investment Holdings Limited | Real estate | 2024 |
| RM Property Investments & Acquisitions Limited | Real estate | 2024 |
| RM Property Services Ltd | Real estate | 2023 |
| RMK Portable Appliance Testing Limited | Administrative & support | 2002 |
| RMP Testing Solutions Limited | Information & communication | 2018 |
| Robian Freeholds (Sussex) Ltd | Real estate | 2022 |
| Robin Rise Road Company Limited | Households | 2006 |
| Robin Stevenson Ltd | Construction | 2020 |
| Robin Stevenson Southern LLP | | 2009 |
| Robinson (South East) Limited | Transport & logistics | 2022 |
| Robinson Consultancy Services Limited | Professional & scientific | 2018 |
| Robus Business Concierge Ltd | Administrative & support | 2020 |
| Robyn Housing Limited | Real estate | 2016 |
| Rocandal Ltd | Professional & scientific | 2011 |
| ROCCA31 Limited | Other services | 2026 |
| Rochester Software Limited | Information & communication | 1996 |
| Rock Pensions Ltd | Professional & scientific | 2018 |
| Rock People Stories Limited | Professional & scientific | 2024 |
| Rock Strategic Consulting Ltd | Professional & scientific | 2018 |
| Rock Trustees Ltd | Extraterritorial | 2018 |
| Rocks and Waves Limited | Manufacturing | 2009 |
| Rocks Woodlands Limited | Agriculture & fishing | 2022 |
| Rocstar Recordings Limited | Information & communication | 2002 |
| Rocyn Limited | Information & communication | 2000 |
| Rodeo Digital Studio Limited | Information & communication | 2025 |
| Rogers Meadow Properties Limited | Real estate | 2017 |
| Rohan Solicitors LLP | | 2013 |
| ROK Skool (Haywards Heath) Limited | Arts & recreation | 2010 |
| ROK Skool Sound Strategies Ltd | Information & communication | 2024 |