DUO checks which exams you have not passed. Before, you had to take these exams 4 times. This will be changed to 3 times. The new rules apply from 1 April.
There are more conditions. These do not change. All conditions are listed on the page Took enough lessons and exams.
Cancelling 4th exam
Did you already register for the 4th exam? You can cancel the exam and get a refund.
For more information, contact DUO.