| RCN Ventures Ltd | Professional & scientific | 2024 |
| RDA Aesthetics Ltd | Health & social care | 2024 |
| RDS Merchants Ltd | Wholesale & retail | 2023 |
| Read QA Limited | Education | 2026 |
| Reap Developments Limited | Extraterritorial | 2007 |
| Red Academy Dance Ltd | Arts & recreation | 2018 |
| Red Academy Fitness Ltd | Arts & recreation | 2024 |
| Red Cloud Film Services Limited | Information & communication | 1997 |
| Red Lion Auto Service Ltd | Wholesale & retail | 2014 |
| Refined Electrical Contractors Ltd | Construction | 2026 |
| REG Group Holdings Limited | Financial services | 2024 |
| REG Group Ltd | Wholesale & retail | 2017 |
| Render & Resin Ltd | Construction | 2021 |
| Renlix Ltd | Administrative & support | 2026 |
| REP & Reform Ltd | Arts & recreation | 2025 |
| Resilience One Limited | Administrative & support | 2007 |
| Rezeebox Properties Ltd | Real estate | 2026 |
| Richaire Limited | Construction | 1972 |
| Richards Electrical Contractors Limited | Construction | 2022 |
| Ridgeway Transport Services (UK) Limited | Transport & logistics | 2014 |
| RIG and Rope Ltd | Professional & scientific | 2024 |
| Rikwoods Presentation Ltd | Manufacturing | 2010 |
| Rioco Communications Ltd | Professional & scientific | 2021 |
| Ritarena Ltd | Health & social care | 2023 |
| Rivacy Ltd | Other services | 2021 |
| Rivers Residential Properties Limited | Real estate | 2020 |
| RJ Leather Studio Ltd | Manufacturing | 2019 |
| RJ Winch Electrical Limited | Construction | 2015 |
| RM Asset Investments Ltd | Real estate | 2021 |
| Roadcraft UK Limited | Wholesale & retail | 1985 |
| Roberts Transport (Sussex) Ltd | Transport & logistics | 2010 |
| Roberts Transport Self Drive Hire Ltd | Administrative & support | 2015 |
| Rocbuild Ltd | Construction | 2022 |
| Rocket Consulting Services Ltd | Professional & scientific | 2026 |
| Rojhat Arda UK Ltd | Hospitality | 2019 |
| Romsey Medical Practice Limited | Health & social care | 2017 |
| Rooting Clouds Ltd | Information & communication | 2022 |
| Roussel Property Group Ltd | Real estate | 2020 |
| RR (Worthing) Limited | Real estate | 2007 |
| RS Auto Services Lancing Limited | Wholesale & retail | 2024 |
| Rstr Holdings Limited | Financial services | 2025 |
| RT Sussex Limited | Extraterritorial | 2019 |
| Rudford Property Management Limited | Real estate | 1999 |
| Rudford Property Storage Ltd | Administrative & support | 2022 |
| Ruhrpumpen Industrial Europa Limited | Manufacturing | 2019 |
| Ruhrpumpen UK Ltd | Manufacturing | 2014 |
| Ruth Booker Limited | Administrative & support | 2006 |
| Rvsb Property Ltd | Real estate | 2025 |
| S & B GRP Roofing Limited | Construction | 2023 |
| S & B Management Consultants Ltd | Other services | 2008 |
| S. P. a. Welding Supplies Limited | Wholesale & retail | 2004 |
| Sabil (Rent) Ltd | Real estate | 2017 |
| Safety Case Partnership Ltd | Professional & scientific | 2022 |
| Safety Wear and Signs Limited | Wholesale & retail | 1981 |
| Sahara Tanning Burgess Hill Ltd | Other services | 2026 |
| Sahara Tanning Haywards Heath Ltd | Other services | 2026 |
| Sahara Tanning Shoreham by Sea Ltd | Other services | 2026 |
| Saint Cosmetics Ltd | Other services | 2022 |
| SAJ Software Consultants Limited | Information & communication | 2025 |
| Saleforsale Ltd | Transport & logistics | 2019 |
| SAM Cowley Ltd | Arts & recreation | 2020 |
| Samasrl Ltd | Health & social care | 2015 |
| Sandbar Deli Limited | Hospitality | 2020 |
| Sandhurst Garden Centre Limited | Real estate | 1975 |
| Sangole Ltd | Real estate | 2018 |
| Sapphire CCS Limited | Administrative & support | 2023 |
| Sara Brunettini Property Limited | Real estate | 2025 |
| Sara Morgan Ltd | Information & communication | 2015 |
| Sarah Stacey and Co Ltd | Administrative & support | 2023 |
| Saunders Quality CMM Programming Ltd | Professional & scientific | 2025 |
| Sawyers Lawn (Freehold) Limited | Administrative & support | 2007 |
| Sbem Ltd | Other services | 2010 |
| SBS Electrical Limited | Construction | 2016 |
| Scene Clean Ltd | Administrative & support | 2026 |
| Scenic Route Ltd | Information & communication | 2013 |
| School of Memphis | Education | 2024 |
| Scout Insurance Services Limited | Financial services | 2004 |
| Scout Shops Limited | Wholesale & retail | 1973 |
| Scout Store EST.1917 Limited | Wholesale & retail | 2018 |
| Scout Store Limited | Wholesale & retail | 2018 |
| Scoutworks Ltd | Other services | 2026 |
| Scrase Estates Limited | Real estate | 2016 |
| SD Brands Ltd | Wholesale & retail | 2011 |
| SD Offshore Limited | Professional & scientific | 2021 |
| Seadom Ltd | Hospitality | 2024 |
| Sealanes Brighton Ltd | Construction | 2017 |
| Sealanes Opco Limited | Hospitality | 2019 |
| Sean Logan Electrical Ltd | Construction | 2017 |
| Seanic Developments Limited | Construction | 2011 |
| Seanowen Electrical Limited | Construction | 2010 |
| Seaspray Media Ltd | Professional & scientific | 2008 |
| Seaview Assets Limited | Real estate | 2025 |
| Seaview Building and Developments Ltd | Construction | 2019 |
| Seaview Building Company Ltd | Construction | 2019 |
| Seaview Landholding Limited | Real estate | 2025 |
| Sebastian Scott Limited | Arts & recreation | 2009 |
| Seevent Plastics Limited | Manufacturing | 1987 |
| SEL Opco Ltd | Real estate | 2022 |
| Sentian Ltd | Professional & scientific | 2024 |
| Sentinel Integrated Systems Limited | Construction | 2025 |