You have been admitted to study a specific programme.  However, you may change to an alternative programme if the School(s) responsible for the programme you wish to leave and the programme you wish to join agree.  A change of programme that includes changing modules can only be made within the first three weeks of each semester.  Further details are available at the following link.

https://intranet.cardiff.ac.uk/students/your-study/changes-to-your-studies/programme-transfers