This page explains what the Worker Registration Scheme (WRS) is and who needs to apply.

If you are a national of the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Slovakia or Slovenia and want to work for one month or more for a United Kingdom employer you must register under the WRS.

Once you have been working legally in the United Kingdom for 12 months without a break you will have full rights of free movement and will no longer need to register on the WRS. You can then get a registration certificate confirming your right to live and work in the United Kingdom, although you are not obliged to do so.