As of 1 July 2013, Croatian nationals are free to move and reside freely in any EEA member state, including the UK. They are subject to a worker authorisation requirement, however, and, in most cases, will need to obtain permission to work in the UK before starting any employment. This will normally take the form of a worker authorisation registration certificate ('purple registration certificate'), for which the Croatian national must apply once sponsored by a UK employer.
Employers wishing to sponsor Croatian nationals will be required to do so under the relevant Tier, ie Tier 2 or Tier 5, by assigning them a Certificate of Sponsorship. The requirements for sponsorship are similar to those applied to all migrant workers, although the skill level for the roles can be slightly lower. Once sponsored, the Croatian national must make an application for a purple registration card, as above, which will give them permission to work for the specific sponsoring employer in the named role. Once the holder of a purple registration certificate has been working in the UK for a period of 12 months without a break, they will no longer require permission from the Home Office to take employment and will be able to undertake any employment they choose. At this point, they can apply for a blue registration certificate to confirm their status.
As above, some Croatian nationals will be exempt from the worker authorisation registration scheme and will be able to immediately undertake employment in the UK, without first seeking specific permission from the Home Office. These individuals must apply for and hold a blue registration certificate to confirm their status. Applicable individuals include: Croatian nationals who qualify as 'highly skilled', in line with the current Tier 1 (Exceptional Talent) structure; and Croatian nationals who have been awarded a recognised Bachelor's, Master's, or PhD degree from a UK Higher Education Institution in the 12 months prior to applying for their blue registration certificate.