You basically have two options if you would like to change to a Bachelor's degree programme and are already studying in a Bachelor's degree programme at another higher education institution:
(1) Application for the first semester. You can apply via hochschulstart.de and the University of Cologne's online portal KLIPS 2.0 (or uni-assist if you are a non-EU applicant). If you are admitted here, equivalent achievements that you have already completed elsewhere can be credited after enrolment. Unfortunately, it is not possible to provide information on the possible creditability of achievements before enrolment. We generally recommend applying for the 1st semester.
(2) In this case, free places in the corresponding semester are allocated. If there are no places available in the semester, there is no chance of a study place in that semester. Which specific achievements will be credited to you will only be decided after enrolment.
If you are currently studying the same degree programme at a university in Germany, you are considered to be a transfer student when applying for a higher semester: In this case, first contact the WiSo Examination Office in writing with this completed form and a current certificate of study. If your change of location status is certified, you can apply for the higher semester with the certificate at the Students Registration Office.
If you are currently studying another degree programme or at a university of applied sciences or abroad, you are a lateral entrant when applying for the higher subject-related semester: In this case, it is assumed that credit points have already been acquired in order to be able to classify you in a higher subject-related semester. In order to be placed in the second semester, you must prove that you have earned at least 15 ECTS credits, the equivalent for the third semester is at least 45 ECTS credits, and so on. Since only equivalent achievements can be recognised and the structure of Bachelor's degree programmes varies greatly from university to university, a "loss" of individual achievements is to be expected.
In order to apply for a higher semester as a lateral entrant, you need this form and a semester classification from the WiSo Examination Office. You can find further information on this, including information on the subsequent crediting of examination achievements, here. On the basis of this semester classification, you can then apply for a higher semester via the Registrar's Office.
The binding application deadlines can be found on the website of the Student's Registration Office: usually 15 September for the winter semester, 15 March for the summer semester. In order to meet these deadlines, the application documents must reach the WiSo Examination Office by post at least eight weeks before the deadline. These are therefore 15.01. and 15.07. respectively.