If you are starting a new course but already have an existing Tier 4 student visa for Aston University, or any other institution in the UK, you are strongly advised against re-entering the UK with your existing visa. Your current visa may have been reported to UK Visas and Immigration (UKVI) and as such may not be valid. You may also be refused entry to the UK if your previous course has finished. (You will not be able to enroll on a new course at Aston University even if you have an existing visa which covers the duration of the course and will have to apply for a new visa).
If you do try and enter the UK on your old visa you must carry your new Confirmation of Acceptance of Studies (CAS) in your hand luggage and be sure that you are able to make a valid visa application on arrival. If you are unable to make a valid visa application on arrival you will not be able to enroll on your course and are likely to be required to return to your home country.
The application from outside the UK is very similar to those applying for a new Tier 4 student visa. For further help on applying from outside of the UK please see here. If you have any problems please contact us.