| Stonepier Consultancy Limited | Professional & scientific | 2022 |
| Stones Lighting Ltd | Information & communication | 2011 |
| Stoolen Ltd | Professional & scientific | 2025 |
| Stop Making Sense Limited | Wholesale & retail | 2008 |
| Store Schools & Projects C.I.C. | Arts & recreation | 2014 |
| Store Store CIC | Education | 2022 |
| Storer Bereavement Services Ltd | Health & social care | 2021 |
| Storm Artist Representation Limited | Arts & recreation | 2015 |
| Storm Cloud Productions Ltd | Information & communication | 2025 |
| Storm Nine Limited | Professional & scientific | 2019 |
| Stormsec Systems Limited | Administrative & support | 2018 |
| Stott & Stevens Ltd | Construction | 2012 |
| Stoute Industries Ltd | Real estate | 2013 |
| Stradbrook Green Ltd | Other services | 2023 |
| Straddeo Limited | Professional & scientific | 2015 |
| Stragglethorpe Energy Limited | Manufacturing | 2015 |
| Strange Safety Ltd | Professional & scientific | 2023 |
| Stranz International Company (UK) Limited | Mining & quarrying | 2026 |
| Strategic BIZ Insight Ltd | Professional & scientific | 2023 |
| Strategic Marketing Solutions Limited | Wholesale & retail | 2025 |
| Strategic Momentum Ltd | Professional & scientific | 2010 |
| Stratford Court Residents Association Limited | Households | 1977 |
| Stratten Holdings Limited | Other services | 2019 |
| Stratton Court (Biggleswade) Management Company Limited | Households | 1981 |
| Stratton House Management Company Limited | Households | 2005 |
| Strawberry Properties Ltd | Real estate | 2022 |
| Streamline MK Ltd | Construction | 2025 |
| Streamline Supply Chain Consulting Ltd | Professional & scientific | 2022 |
| Streams Consult Limited | Information & communication | 2024 |
| Streets Sibling Ltd | Wholesale & retail | 2008 |
| Strength Made Simple Limited | Administrative & support | 2016 |
| Strikepoint Advisory Ltd | Information & communication | 2026 |
| Strive Engineering Limited | Professional & scientific | 2025 |
| Strivor Capital Limited | Financial services | 2025 |
| Structured Approach Limited | Information & communication | 2013 |
| Strytech Limited | Information & communication | 2022 |
| STS Imports Ltd | Wholesale & retail | 2024 |
| Stuart Brown Limited | Wholesale & retail | 2003 |
| Stuart Mccabe Fitness Academy Limited | Other services | 2024 |
| Student Berries Ltd | Hospitality | 2024 |
| Student Breakthrough Ltd | Education | 2018 |
| Studio 23 Beauty Ltd | Other services | 2026 |
| Studio 281 (MK) Ltd | Education | 2019 |
| Studio 281 Academy Ltd | Other services | 2019 |
| Studio 281 Ampthill Ltd | Arts & recreation | 2025 |
| Studio 281 Bedford Ltd | Arts & recreation | 2017 |
| Studio 281 Cambridge Ltd | Arts & recreation | 2025 |
| Studio 281 Enterprises Ltd | Other services | 2017 |
| Studio 281 Holdings Ltd | Financial services | 2025 |
| Studio 281 Olney Ltd | Arts & recreation | 2025 |
| Studio 57 Productions Ltd | Arts & recreation | 2015 |
| Studio AI Architecture & Interiors Ltd | Professional & scientific | 2023 |
| Studio Alux Ltd | Arts & recreation | 2025 |
| Studio Archer Limited | Professional & scientific | 2020 |
| Studio Booth Ltd | Construction | 2020 |
| Studio Louca Design Limited | Professional & scientific | 2025 |
| Studio Swanworth Ltd | Administrative & support | 2021 |
| Studs&Truck Ltd | Construction | 2019 |
| Studybugs Limited | Information & communication | 2013 |
| Stukeley Park Freehold Limited | Real estate | 2006 |
| Stukeley Park Limited | Real estate | 1989 |
| Stutley Brothers Limited | Real estate | 1934 |
| Stylenote Limited | Wholesale & retail | 1999 |
| Stylysh Edition Ltd | Other services | 2026 |
| Suame African Market Ltd | Wholesale & retail | 2026 |
| SUB Construction Ltd | Construction | 2020 |
| SUB Seven Limited | Administrative & support | 2026 |
| Subdigita Limited | Information & communication | 2017 |
| Submit IT Limited | Professional & scientific | 2008 |
| Substratum Consulting Limited | Professional & scientific | 2015 |
| Such Music Ltd | Arts & recreation | 2025 |
| Suffield Road Limited | Real estate | 2022 |
| Suffolk Plants Limited | Wholesale & retail | 2016 |
| Sufo Creatives Ltd | Arts & recreation | 2024 |
| Sugarcube Creatives Ltd | Information & communication | 2026 |
| Suiker Consulting Sevices Limited | Financial services | 2021 |
| Suisse PHL (Propco) Limited | Real estate | 2018 |
| Sukarika Market Limited | Wholesale & retail | 2026 |
| Sukh Invests Limited | Financial services | 2023 |
| Sukiseo Limited | Professional & scientific | 2017 |
| Suluko Ltd | Arts & recreation | 2016 |
| Summer Gardens (Banbury) Management Company Limited | Households | 2003 |
| Summerhouse Hill Ltd | Hospitality | 2024 |
| Summit Blasting Limited | Construction | 2015 |
| Summit Pulse Medical Ltd | Health & social care | 2025 |
| Summus Technology Solutions Ltd | Information & communication | 2010 |
| Sumsa Ltd | Financial services | 2025 |
| Sun Aesthetics Limited | Health & social care | 2023 |
| Sun and Star Properties Limited | Real estate | 2015 |
| Sun Realm Heating Services Limited | Professional & scientific | 1977 |
| Sunbeam Heating Limited | | 1981 |
| Sunda Desserts Ltd | Hospitality | 2024 |
| Sunda Properties Ltd | Real estate | 2019 |
| Sundew Doctors Limited | Health & social care | 2015 |
| Sungold Systems (UK) Limited | Other services | 1995 |
| Sunlife Healthcare Professionals Limited | Health & social care | 2019 |
| Sunlit Minds Limited | Wholesale & retail | 2024 |
| Sunrest Limited | Wholesale & retail | 2017 |
| Sunset Building Co. Limited | Construction | 2004 |
| Sunset Commercial Finance Limited | Professional & scientific | 2016 |