The test dates for 2018 are fixed. Here you can find all test dates, locations and deadlines.
The BT-WISO can only be taken at certified test centres on respectively scheduled dates.
Starting in 2017, the BT-WISO can also be taken in English In English the BT-WISO is called BT-BASE. The test language can be chosen within the registration process. We recommend that you check with the university to which you plan to apply as to which language version(s) it accepts.