If you registered for P4 but finally can’t make it (from an email from the administration):

Yet it appears that many students and mentors are not yet clear what exactly has to be done when a student withdrawals for his/her P4 presentation. In any case, the student must also inform the entire mentors team and the delegate examiner. Also the student must sent a email to the Board of Examiners (examencommissie-bk@tudelft.nl) stating his/her name and student number and declare that he/she withdrawal the P4. The next possibility for holding a P4 presentation is in September/October. They receive a confirmation from me that the withdrawal has been processed administratively, the P4 presentation is also removed from the schedule and the student is told when the next P4 period is. For this P4 period (September/October), the student must also submit a P4 application form with all signatures to me.