| Today ISP B.V. | South Holland |
| Tomassen ICT Services B.V. | Gelderland |
| TomTom International B.V. | North Holland |
| ToolsGroup B.V. | |
| TopAI.tools | |
| Topic Embedded Systems | South Holland |
| Topnetworks InternetService | |
| Torro Studio | |
| Totaalnet Internet Works B.V. | Gelderland |
| Total Power Europe B.V. | North Brabant |
| Totall-iT B.V. | North Holland |
| Totally Hosted | Flevoland |
| Touchtribe | |
| Town | North Brabant |
| Toxys | South Holland |
| Tracey | |
| Trade Games International B.V. | South Holland |
| Tradecast | |
| Tradefox | North Holland |
| Traffic Builders | Flevoland |
| TrafficLink B.V. | North Holland |
| Trajectplanner | Overijssel |
| Transceptor Technology | |
| Transfer DSW | Overijssel |
| Transfer Solutions | Utrecht |
| Transip | South Holland |
| TransIP International | South Holland |
| Transnationale Universiteit Limburg | |
| Travis the Translator | South Holland |
| Travsys B.V. | Utrecht |
| Treetop | |
| Treeway B.V. | |
| Trendiq B.V. | South Holland |
| Trends ICT Groep | South Holland |
| TrendWatching B.V. | North Holland |
| Trendwerk | Overijssel |
| Trengo | Utrecht |
| Tres | Friesland |
| Tri-Torque Technology | North Brabant |
| Tribes | |
| Triggre | Utrecht |
| Trilobiet | South Holland |
| TriLogic+ Automation B.V. | North Holland |
| Trim Tab | |
| Triodor Software | North Holland |
| Triodos Bank N.V. | |
| TriOpSys | Utrecht |
| Tripetto | North Holland |
| Triple | South Holland |
| Triple B IT Beheer | |