| Synichoe Ltd | Manufacturing | 2024 |
| Syntactics Limited | Information & communication | 1996 |
| T & C Business Consultants Limited | Professional & scientific | 1986 |
| T & D Oram Limited | Agriculture & fishing | 2001 |
| T & S Property Development Limited | Construction | 2003 |
| T and T Serivces Ltd | Information & communication | 2023 |
| T B Marine Services Limited | Construction | 2002 |
| T ORR Roofing Ltd | Construction | 2019 |
| T.H. Harries & Co. Limited | Wholesale & retail | 1939 |
| TA RENT2RENTS Ltd | Hospitality | 2023 |
| Tailbloomdesigns Ltd | Wholesale & retail | 2025 |
| Tailbloomresin Ltd | Wholesale & retail | 2025 |
| Tailwispdecor Ltd | Wholesale & retail | 2025 |
| Taishan Ventures Ltd | Wholesale & retail | 2019 |
| TAJ Mahal Suffolk Ltd | Hospitality | 2018 |
| Tamos Medical Ltd | Health & social care | 2023 |
| Tarkell Limited | Hospitality | 2007 |
| Tasty Fill | | 1996 |
| Tatlici Kose Ltd | Wholesale & retail | 2025 |
| Tattersalls Limited | Wholesale & retail | 1964 |
| Taveto Limited | Wholesale & retail | 2012 |
| Taylor Made Home Solutions Ltd | Construction | 2021 |
| TBI Manufacturing Limited | Manufacturing | 1988 |
| TCG Electrical & Consultancy Services Limited | Information & communication | 2006 |
| TD & Partners Global Limited | Other services | 2022 |
| Team Players Limited | Arts & recreation | 2003 |
| Team Regen Ltd | Wholesale & retail | 2022 |
| Technect Ltd | Information & communication | 2022 |
| TEK Noire Ltd | Wholesale & retail | 2026 |
| Tempest Designs Limited | Professional & scientific | 1995 |
| Teneco East Limited | Other services | 2002 |
| Tenza Technologies Limited | Manufacturing | 1986 |
| Terence Dalton Limited | Information & communication | 1959 |
| Terix Limited | Information & communication | 1988 |
| Terra Costa | | 2005 |
| Thatch Shield Limited | Financial services | 1996 |
| THE Art of British Song Ltd | Arts & recreation | 2021 |
| THE Bartrum Group Limited | Professional & scientific | 1993 |
| THE Bradley Collection Limited | Manufacturing | 1992 |
| THE British Biomass Company Limited | Manufacturing | 2011 |
| THE Bundle Cabin Ltd | Wholesale & retail | 2019 |
| THE Cabelo Boutique Ltd | Financial services | 2023 |
| THE Card Centre Felixstowe Limited | Wholesale & retail | 2003 |
| THE Cartridge Refill Centre Limited | Wholesale & retail | 2004 |
| THE Castlebridge Consignment Limited | Administrative & support | 2005 |
| THE Coaching Body Limited | Education | 2023 |
| THE Corner Stores (Suffolk) Limited | Wholesale & retail | 2003 |
| THE Dance Factory (Suffolk) Limited | Arts & recreation | 2003 |
| THE Equine Supply Company Limited | Wholesale & retail | 2010 |
| THE Finch Connection Ltd. | Professional & scientific | 2015 |
| THE Five Castles Press Limited | Manufacturing | 2002 |
| THE Food Museum Ltd | Arts & recreation | 1984 |
| THE Gainsborough Silk Weaving Company Limited | Manufacturing | 2004 |
| THE GAS Shop (Felixstowe) Limited | Wholesale & retail | 1998 |
| THE Green Energy Assessor Ltd | Professional & scientific | 2025 |
| THE Grey Pumpkin Ltd | Education | 2024 |
| THE Guineas Racing Ltd | Agriculture & fishing | 2025 |
| THE Herma Partnership | | 1991 |
| THE HMO Property Agency Limited | Real estate | 2020 |
| THE Humphries Weaving Company Limited | Manufacturing | 2005 |
| THE Ipswich School of Dancing LLP | | 2002 |
| THE Luxury Brand Group Limited | Extraterritorial | 2019 |
| THE OLE Frank Limited | Hospitality | 2006 |
| THE Park Farm, Syleham Limited Partnership | | 2009 |
| THE Real Sausage Company Limited | Wholesale & retail | 2001 |
| THE Simple Consultancy RSL Ltd | Professional & scientific | 2023 |
| THE Upperset Hairdressing Salon | | 1990 |
| The-Kairos Limited | Wholesale & retail | 2024 |
| Thehomeedmama Ltd | Information & communication | 2024 |
| Thetoyland Limited | Wholesale & retail | 2024 |
| Thinkbridge Ltd | Information & communication | 2025 |
| Thinkplace Limited | Information & communication | 2001 |
| Thirty Plus One Limited | Information & communication | 2015 |
| Thrive Hub Innovations Ltd | Professional & scientific | 2020 |
| Tian Cheng Ad&Communication Limited | Wholesale & retail | 2021 |
| Tiber Road Limited | Real estate | 2025 |
| TIC INT' Limited | Other services | 2019 |
| Tidemill Yacht Harbour Limited | Arts & recreation | 1987 |
| Tidydrive Co Ltd | Wholesale & retail | 2024 |
| Tilbrook's Holdings Limited | Professional & scientific | 2005 |
| TIM Moll Architecture Limited | Professional & scientific | 2003 |
| Timberwolf Limited | Manufacturing | 1997 |
| Tinker Squad Ltd | Wholesale & retail | 2016 |
| Tipton TM Ltd | Construction | 2022 |
| Titanspear Company Ltd | Financial services | 2023 |
| TLD Investments Ltd | Real estate | 2023 |
| Tlinkto Limited | Wholesale & retail | 2023 |
| TMB Brands Ltd | Wholesale & retail | 2025 |
| Tobren Limited | Professional & scientific | 1987 |
| Tony Turkish Barber Ltd | Other services | 2018 |
| Toolbox Marketing Services Ltd | Administrative & support | 2021 |
| Travel Yakata Limited | Administrative & support | 2023 |
| Trinity Books Ltd | Information & communication | 2021 |
| Trinity Kings Media Ltd | Information & communication | 2023 |
| Tronicquest Limited | | 1984 |
| True Haven Homes Ltd | Real estate | 2025 |
| True Healing Limited | Health & social care | 2005 |
| Trumbar Truck Care Limited | Wholesale & retail | 1978 |
| Tuen Hing FA Limited | Hospitality | 2024 |
| Tumu Property Limited | Real estate | 2024 |