TOEFL The minimum TOEFL score required is 79 for the internet-based test, with a minimum writing score of 20. The minimum TOEFL score for the paper-based exam is 550, with a minimum writing score of 58.TOEFL scores must be received directly from Educational Testing Service (ETS). The University of Houston's ETS Institutional Code is 6870. IELTS The minimum IELTS score required is an overall score of a 6.5, with a minimum writing score of 6.5. The testing agency should mail the official results directly to the University of Houston. GRE GRE scores — Valid for 5 years from the original date taken (Upload to University code 6870)