| Rumour Consultancy Ltd | Professional & scientific | 2018 |
| Run My Clinics Limited | Health & social care | 2025 |
| Russell Matthews Limited | Real estate | 1999 |
| S G a Systems Limited | Information & communication | 2007 |
| S L Hotel Ltd | Hospitality | 2004 |
| S R Structures Limited | Manufacturing | 2023 |
| S, a & K Consulting Ltd | Information & communication | 2021 |
| S-Cinco Limited | Other services | 2015 |
| Saarena Consulting Limited | Professional & scientific | 2014 |
| Sabai Services Ltd | Construction | 2022 |
| Sadorp Brands Limited | Wholesale & retail | 2025 |
| Sadorp Global Holdings Ltd | Financial services | 2025 |
| Sadorp Holdings Limited | Financial services | 2024 |
| Sadorp UK Limited | Wholesale & retail | 2024 |
| Sait CNC Solutions Ltd | Manufacturing | 2025 |
| SAL Marine Limited | Manufacturing | 2003 |
| Saliann Ltd | Administrative & support | 2019 |
| Salisbury Antiques Centre Limited | Wholesale & retail | 2007 |
| Salix Interior Design Ltd | Professional & scientific | 2024 |
| Sally Harbut Ltd | Other services | 2024 |
| Salt & Heather Ltd | Professional & scientific | 2018 |
| Salterns END Properties Limited | Real estate | 1998 |
| Salternshill Consulting Ltd | Professional & scientific | 2025 |
| Saltware Solutions Limited | Information & communication | 2024 |
| Sampas Limited | Administrative & support | 2018 |
| Sanders Sails Limited | Manufacturing | 2003 |
| Sandfield Court Limited | Real estate | 2004 |
| Sans Frontiere Marketing Limited | Wholesale & retail | 1997 |
| Sarapino Global Foods Limited | Manufacturing | 2016 |
| Sarapino Limited | Manufacturing | 2014 |
| Sarnia Installations Ltd | Construction | 2018 |
| Savings Pittstop Ltd | Wholesale & retail | 2024 |
| Scarangar Travel Ltd | Hospitality | 2022 |
| Scholars Retreat Management Company Limited | Households | 2004 |
| School Lane Management Limited | Households | 1990 |
| Schroeder Knight Limited | Information & communication | 2000 |
| Scorpion Vision Limited | Wholesale & retail | 2006 |
| Scorvino Limited | Wholesale & retail | 2020 |
| Scott Bailey Properties LLP | | 2017 |
| Scriptex Limited | Health & social care | 2018 |
| Sea Maine Export Limited | Agriculture & fishing | 2017 |
| Sea Talk Systems Limited | Professional & scientific | 1997 |
| Sea Venues Limited | Transport & logistics | 2003 |
| Seacrest Properties Limited | Real estate | 2009 |
| Seahorse Rating Limited | Other services | 1986 |
| Seans Solutions Ltd | Professional & scientific | 2026 |
| Seapoint Construction Limited | Construction | 2001 |
| Seatrain Ltd | Professional & scientific | 2020 |
| Second Family Ltd | Health & social care | 2021 |
| SEE the Sights Tours Ltd | Arts & recreation | 2023 |
| Sefton Court (Milford-On-Sea) Limited | Hospitality | 1963 |
| Semidyne Ltd | Extraterritorial | 2010 |
| September Care (Holdings) Ltd | Real estate | 2019 |
| Serdet Ltd | Wholesale & retail | 2024 |
| Sesl Ltd | Health & social care | 2024 |
| Setley Holdings Limited | Professional & scientific | 1972 |
| Sewing Machine Workshop Limited | Other services | 2014 |
| SFP Electrical Ltd | Manufacturing | 2011 |
| SG Marketing (Property) Limited | Professional & scientific | 2019 |
| Sgtv Limited | Information & communication | 2003 |
| Shaftserv Ltd | Manufacturing | 2025 |
| Shantha Payso Limited | Administrative & support | 2018 |
| Shareyourjob.Com Ltd | Administrative & support | 2009 |
| Shearsmith Ltd | Real estate | 2025 |
| SHEDS4BOATS Ltd | Manufacturing | 2024 |
| Shepherds Prospect Consulting Limited | Health & social care | 2025 |
| Shepherds Way Residents Limited | Administrative & support | 2020 |
| Shine Group Holdings Limited | Administrative & support | 2025 |
| Shore Close Flats Limited | Households | 1963 |
| Shore Supported Housing Services Limited | Health & social care | 2012 |
| Shoreline Autos Ltd | Wholesale & retail | 2025 |
| Shorts Electrical Contractors Limited | Construction | 1998 |
| Shrine Holding Ltd | Financial services | 2023 |
| Shrine Retail Ltd | Wholesale & retail | 2023 |
| Si-Kaust Management Company Limited | Households | 1998 |
| Sieben-Roberts Consulting Ltd | Professional & scientific | 2025 |
| Sign BSL Ltd | Professional & scientific | 2021 |
| Sign IT Branding Solutions Ltd | Administrative & support | 2025 |
| Signature D Aesthetics Ltd | Other services | 2023 |
| Signature D Limited | Public administration | 2019 |
| Signina Limited | Administrative & support | 2013 |
| Silva Oak Ltd | Administrative & support | 2025 |
| Silver Street Associates LLP | | 2011 |
| Silver Street Estates Limited | Information & communication | 2001 |
| Silverbox Designer Jewellery (Christchurch) Ltd | Wholesale & retail | 2013 |
| Silverbox Online Limited | Wholesale & retail | 2017 |
| Silverfern Building Services Limited | Construction | 2019 |
| Silvergate Ltd | Extraterritorial | 2021 |
| Silvergate Property Ltd | Hospitality | 2021 |
| Silverland Estates Limited | Real estate | 2018 |
| Simon Helyar Ltd | Health & social care | 2023 |
| Simon Young Ltd | Construction | 2020 |
| Simpen & Company Limited | Real estate | 1995 |
| Sinclair's Fine Wine Limited | Wholesale & retail | 2026 |
| Sips Spaces Limited | Administrative & support | 2021 |
| Sivad (New Forest) Limited | Administrative & support | 2005 |
| SJH Properties Hampshire Limited | Real estate | 1978 |
| SJP Marine Enterprises Ltd | Arts & recreation | 2013 |
| Skippers Online Ltd | Professional & scientific | 2005 |
| Sky Blue Developments Limited | Real estate | 2000 |