| Stetchworth Properties Limited | Financial services | 2025 |
| Steven Seals Builder Limited | Construction | 2009 |
| Stickywrap UK Limited | Manufacturing | 2025 |
| Stiffkey Farms Limited | Agriculture & fishing | 1985 |
| Stilton Butchers Group UK Ltd | Wholesale & retail | 2026 |
| Stimela Claims Consultants Ltd | Professional & scientific | 2022 |
| Stonegate Creative Limited | Construction | 2021 |
| Stonetree Developments Ltd | Real estate | 2011 |
| Stories Projects in Film Ltd | Information & communication | 2015 |
| Storm Cloud Properties Ltd | Real estate | 2025 |
| Straiton Software Limited | Information & communication | 2004 |
| Stratton Recruitment Limited | Administrative & support | 2018 |
| Street Cafe Bistro Ltd | Hospitality | 2024 |
| Strong Intentions Ltd | Health & social care | 2022 |
| Struain (Projects) Ltd | Construction | 2017 |
| Stuart C Williams Racehorse Training & Management Limited | Arts & recreation | 2003 |
| Student Property Investments Limited | Real estate | 2007 |
| Studio Scribbles Limited | Wholesale & retail | 2015 |
| Studlands Business Centre Management Company Limited | Real estate | 1985 |
| Styxx Ltd | Hospitality | 2024 |
| SU Ltd | Extraterritorial | 2008 |
| Suffolk Community Enterprises Ltd | Administrative & support | 2015 |
| Suffolk Handmade Kitchens LLP | | 2012 |
| Suffolk Hideaways Limited | Professional & scientific | 2016 |
| Suffolk PE & Sport Network CIC | Arts & recreation | 2023 |
| Suffolk Unique Dog Services Ltd | Other services | 2026 |
| SUFFOLK32 Limited | Hospitality | 2019 |
| Sunbaba Marketing Services Limited | Wholesale & retail | 1987 |
| Sunbaba Systems Limited | Wholesale & retail | 1988 |
| Sunnyside Park Lane Residents Association Limited | Households | 1976 |
| Sunparadise Systems Ltd | Construction | 2004 |
| Sunrise Blinds & Conservatories Ltd. | Manufacturing | 2004 |
| Sunrise Blinds Limited | Manufacturing | 2009 |
| Superfood Newmarket Ltd | Hospitality | 2023 |
| Supernet Communications Limited | Construction | 2019 |
| Supporting Positively Limited | Professional & scientific | 2020 |
| Surrey Environmental Services (Pest Control Division) Limited | Other services | 1996 |
| Susan Hart Podiatry/Chiropody Services Ltd | Health & social care | 2013 |
| SW Electrical Services (UK) Limited | Construction | 2006 |
| SW Limited | Extraterritorial | 2007 |
| Sw&A East Limited | Professional & scientific | 2023 |
| Swarbrick IP Ltd | Professional & scientific | 2025 |
| Swarthy INK Ltd | Wholesale & retail | 2023 |
| SWE Group Ltd | Real estate | 2021 |
| Sweet Temtation Ltd | Manufacturing | 2025 |
| Sweetie City Ltd | Wholesale & retail | 2020 |
| Swift Recruit U.K Limited | Administrative & support | 2023 |
| Synagia Thermodynamics Limited | Extraterritorial | 2009 |
| Syronos Ltd | Information & communication | 2021 |
| T Carson Racing Ltd | Arts & recreation | 2019 |
| T Clover Racing Limited | Agriculture & fishing | 2020 |
| T&A Turner Limited | Professional & scientific | 2022 |
| T.R. Owen Limited | Financial services | 2007 |
| T2V Holdings Ltd | Administrative & support | 2024 |
| Taac Educational Consultancy Limited | Education | 2013 |
| Taleno Investments Ltd | Real estate | 2023 |
| Talisonny Thoroughbred Consultants Limited | Professional & scientific | 2015 |
| Tamok Racing Limited | Arts & recreation | 2024 |
| Tantivy Ltd | Arts & recreation | 2025 |
| Tappi Ltd | Information & communication | 2014 |
| TAW Automotive Limited | Administrative & support | 2025 |
| TAW Capital Holdings Limited | Financial services | 2025 |
| TAW Enterprises 1 Limited | Hospitality | 2025 |
| TAW Investments Limited | Professional & scientific | 2025 |
| TAW Partners Ltd | Professional & scientific | 2025 |
| TAW Real Estate Limited | Real estate | 2025 |
| Tax&Co Ltd | Professional & scientific | 2024 |
| Taylor Brothers Steam Group Limited | Other services | 2021 |
| TC Property Developments Ltd | Construction | 2013 |
| Tclass Buildres Ltd | Construction | 2026 |
| TCW Technology Services Ltd | Information & communication | 2024 |
| TD Estates Ltd | Real estate | 2020 |
| TD Ltd | Extraterritorial | 2009 |
| TE Ltd | Extraterritorial | 2009 |
| Tecforyou Ltd | Wholesale & retail | 2022 |
| Techmaster Mobile Ltd | Manufacturing | 2022 |
| Tecom International Limited | Professional & scientific | 2017 |
| Teevan Consulting Network Limited | Professional & scientific | 2004 |
| TEN Hats Limited | Professional & scientific | 2014 |
| Tennis Industry Association UK Limited | Other services | 2005 |
| Test and Evaluation Limited | Administrative & support | 2017 |
| TG Ltd | Extraterritorial | 2009 |
| TGM Financial Services Ltd | Professional & scientific | 2021 |
| Thai Elephant & Castle Ltd | Hospitality | 2025 |
| Thain Properties Limited | Real estate | 2008 |
| That Engineering Company Limited | Manufacturing | 2011 |
| THE Anglia Comedy Co. LLP | | 2022 |
| THE B.E.E.F. (Business Benefits) Limited | Other services | 2014 |
| THE Barber Shop Cambridge Limited | Other services | 2003 |
| THE Beauty Platform Ltd | Other services | 2023 |
| THE Black BOY Sudbury Ltd | Hospitality | 2017 |
| THE BN Shop Ltd | Wholesale & retail | 2025 |
| THE Botanical Alchemist Limited | Wholesale & retail | 2019 |
| THE Branch Ministries Limited | Other services | 2024 |
| THE Braughing Sausage Company Limited | Wholesale & retail | 2006 |
| THE Breeze UP Consignors Limited | Professional & scientific | 2017 |
| THE Brew Quarters Ltd | Hospitality | 2022 |
| THE British Bloodstock Agency Limited | Professional & scientific | 1993 |
| THE Business Machines Company (UK) Limited | Administrative & support | 1990 |
| THE Cambridge Loft Company Limited | Construction | 2017 |