If you are doing a doctorate at Technische Universität Braunschweig, you are entitled to enrol as a student for the purpose of your doctorate. You will then have full student status with all the associated rights and obligations.
In order to enrol for a doctorate, you must meet the necessary requirements and comply with the required formalities. The requirements for doctoral studies are checked by the faculties. Therefore, please contact the doctoral office of the faculty responsible for you before enrolling for a doctorate.
There are no deadlines for enrolment for a doctorate, i.e. you can enrol at any time during the semester. Enrolment is always valid for an entire semester, so the full semester fee is due accordingly. Therefore, it will be recommend to apply for enrolment before or at the beginning of the semester if possible.
If you have an international university degree, please check the website of the Welcome Support for International Researchers at TU Braunschweig before enrolment:
Welcome Support for International Researchers
Following online enrolment, your data will be transmitted electronically to the Enrolment Office. On the last page of the online enrolment, you can upload the required documents in the corresponding fields. Enrolment can only take place once you have uploaded all the required documents.
If you are already enrolled at TU Braunschweig and would now like to switch to doctoral studies, you must first re-register for the coming semester by transferring the semester fee. Once this has been done, log in to the TUconnect portal with your user ID and start an online application for the desired degree program with the degree goal "Doctorate" via "Study offers" > "Study application". At the end of the process, you will be shown upload fields in which you must upload the adjacent documents.
The usual re-registration deadlines also apply to doctoral students. See also here