Semesters at the Preparatory School have different start and finish dates to those at TU Berlin.

Summer semester: 1 February until 31 August
Winter semester: 1 September until 31 January

The start can vary by a few days from year to year.

For the T and W focus courses and the Propädeutikum (via uni-assist)
Application for summer semester: 15 September to 30 November
Application for the winter semester: 15 March to 30 June

For the external assessment test and supplementary test (via uni-assist)
Application to take the tests in the summer semester (June/July): 15 September until 28 February
Application to take the tests in the winter semester (December/January): 15 March to 31 August

Admissions test for applicants with professional qualifications (via the Preparatory School)
The admissions test takes place parallel to the assessment test at the end of the summer and winter semesters (June/July and December/January). Please contact the Preparatory School approximately three months prior to the date of the assessment test. 
Application to take the test in the summer semester at the latest until 15 March by email studienkolleg(at)tu-berlin.de
Appication to take the test in the winter semester at the latest until 15 September by email studienkolleg(at)tu-berlin.de