If the course you want to change to is the same length and same level as your existing course (from one MA to another MA, for example) then it may not affect your visa.  We may need to tell the Home Office if you've changed course, but you won't need a visa extension if the course you switch to is the same length. 

Please be aware that the course you switch to must have the same entry criteria - if there are additional entry criteria then you may not be able to switch without returning home and applying for a new visa.

If you are considering changing courses, you should contact your Subject Director and also let the Visa & Compliance team know at visa@yorksj.ac.uk.