Croatia became part of the European Union on 1 July 2013. However, the UK Government has restricted access to employment in the UK for Croatians. This is likely to be for a period of five years from accession, with the possibility of an additional two years if the UK government can provide evidence that there remains a serious disturbance to the labour market to justify this extension.
A standstill clause applies when any country joins the European Union. In practise, this means that existing European Member States cannot make access to their labour markets any more restrictive than was the case at the date of the signature of the Accession Treaty, which in the case of Croatia was on 9 December 2011. However, Member States can choose to be more generous.
Croatians enjoy a right of residence in the UK as students, just as other EEA students do. As a student, you are not subject to worker authorisation. However, if you want to take any employment in the UK, you have to obtain a yellow registration certificate before you start unless you are either exempt or still have student immigration permission.