| RPM Site Management Ltd | Construction | 2019 |
| Rpmd Invest Limited | Real estate | 2016 |
| RR Land and Buildings Limited | Real estate | 2013 |
| RR SW Ltd | Health & social care | 2022 |
| Rrml (Rebecca’S) Kitchen Ltd | Hospitality | 2023 |
| Rrml Ltd | Hospitality | 2025 |
| RS Locum Services Limited | Health & social care | 2023 |
| RSF Health Limited | Health & social care | 2022 |
| RSF1 Limited | Real estate | 2020 |
| RSG MOT Service Centre Ltd | Wholesale & retail | 2026 |
| RSI Services Ltd | Real estate | 2022 |
| RSP Architects Limited | Professional & scientific | 2007 |
| RSW 247 Ltd | Real estate | 2024 |
| Rubberdesk UK Ltd | Real estate | 2020 |
| Ruben Van Alebeek Consulting Ltd | Information & communication | 2023 |
| Rubex UK Limited | Wholesale & retail | 2010 |
| Rubicon Regeneration Limited | Professional & scientific | 2000 |
| Rubicon Resilience Limited | Other services | 2016 |
| Ruby Marketing Ltd | Administrative & support | 2017 |
| Ruby Red Training Limited | Professional & scientific | 2023 |
| Ruby Zena Ltd | Arts & recreation | 2024 |
| Ruci Media Ltd | Professional & scientific | 2017 |
| Rudy UN Limited | Information & communication | 2021 |
| Rugbytots Sussex by the Sea LLP | | 2022 |
| Rule 58 Limited | Wholesale & retail | 2013 |
| Ruminate Ltd | Professional & scientific | 2018 |
| Run Like the Wolf Ltd | Health & social care | 2021 |
| Run of the Mill Productions Ltd | Arts & recreation | 2015 |
| Run Shop Limited | Wholesale & retail | 2002 |
| Runner Duck Games Independent Ltd | Information & communication | 2026 |
| Runner London Ltd | Wholesale & retail | 2018 |
| Rupert Toovey Antique & Fine Art Valuations Limited | Other services | 2005 |
| Rurouni Limited | Information & communication | 2023 |
| Russell Keefe Limited | Arts & recreation | 2002 |
| Russell Mews (Brighton) Limited | Households | 2016 |
| Russell Rooms Ltd | Real estate | 2018 |
| Russets Investment Ltd | Real estate | 2021 |
| Ruta KA Holistic Health Ltd | Health & social care | 2021 |
| Rutland Gardens Management Limited | Households | 1993 |
| Rutland Nivas Limited | Households | 2020 |
| Ruxley Investments Limited | Financial services | 2018 |
| RW Building Ltd | Construction | 2020 |
| Rweg Limited | Other services | 2004 |
| RWN Trading Limited | Extraterritorial | 2005 |
| Rxcd Ltd | Health & social care | 2023 |
| Ryan Havoc Taylor Limited | Information & communication | 2022 |
| Ryan RDC Limited | Professional & scientific | 2026 |
| Ryde Court RTM Company Limited | Households | 2024 |
| Ryvo App Ltd | Information & communication | 2026 |
| S & H Brickwork Contractors Ltd | Construction | 2011 |
| S and S Acquisitions Limited | Real estate | 2025 |
| S D Electrical Contractors Ltd | Construction | 2015 |
| S E Lifts Ltd | Extraterritorial | 2023 |
| S E Technical Limited | Manufacturing | 2018 |
| S Growth Partners Limited | Professional & scientific | 2023 |
| S J Hull Consulting Limited | Professional & scientific | 2023 |
| S J Metals Limited | Wholesale & retail | 2003 |
| S J R (UK) Limited | Real estate | 2010 |
| S P Sussex Ltd | Construction | 2026 |
| S W W C Ltd | Construction | 2016 |
| S Waters Decorating Limited | Construction | 2005 |
| S&C Block Management Limited | Extraterritorial | 2023 |
| S&H Bookkeeping Ltd | Professional & scientific | 2019 |
| S&J Pipework & Building Limited | Construction | 2025 |
| S'Osei Ltd | Wholesale & retail | 2025 |
| S. T. Productions Ltd | Arts & recreation | 2015 |
| S.D. (Sussex) Ltd | Other services | 2008 |
| S.Lewis Property Services Limited | Construction | 2006 |
| S.R. Solar Heat Limited | | 1977 |
| S.T.F. Start to Finish (Sussex) Ltd | Construction | 2019 |
| S25 Dental Limited | Health & social care | 2024 |
| S4 BAH Limited | Administrative & support | 2019 |
| SA Creative Labs Limited | Information & communication | 2013 |
| Saas Power Ltd | Information & communication | 2025 |
| SAC Holdings Limited | Professional & scientific | 2004 |
| SAC RTM Company Limited | Extraterritorial | 2024 |
| Sackville Pizza Ltd | Hospitality | 2024 |
| Sackville Property Management Limited | Households | 2024 |
| Sackville Road Orthodontic Clinic Limited | Health & social care | 2009 |
| Sackville United RTM Company Limited | Households | 2019 |
| Sacrosanct Hospitality Ltd | Hospitality | 2025 |
| Sadikot Solutions Ltd | Construction | 2017 |
| Sadza Limited | Health & social care | 2022 |
| Safeday Consultancy Services Ltd | Professional & scientific | 2024 |
| Saffron Gallacher Ltd | Administrative & support | 2019 |
| Saffron Yard Limited | Hospitality | 2025 |
| Sagar Properties Ltd | Real estate | 1999 |
| Sage Company Branding & Print Ltd | Manufacturing | 2023 |
| Sage Roxborough Limited | Financial services | 2005 |
| Sagelabs Ltd | Information & communication | 2019 |
| Saghir Holdings Ltd | Real estate | 2020 |
| Sahand Foods Limited | Hospitality | 2022 |
| Sahas Consulting Limited | Professional & scientific | 2023 |
| Sahas Properties Limited | Real estate | 2017 |
| Sahas Sussex Limited | Hospitality | 2021 |
| Saheera Store Ltd | Wholesale & retail | 2025 |
| Sahell Limited | Wholesale & retail | 2021 |
| Sahoori Limited | Hospitality | 2025 |
| Saifi Tech Limited | Wholesale & retail | 2025 |
| Sailing by Night Limited | Information & communication | 2012 |