All EEA Nationals are required to register if they want to stay for longer than a period of 183 days but the registration process is very easy. We recommend to do a booking so you can avoid the longer waiting ques.
The website of immigration provides a good deal of info about what do you need and how to get it.
All of the required information can be found here, with even the forms required to fill out but basically you’ll need to bring your work contract or proof of address like a rental contract, your passport and 1000FT for the fees and they’ll fix it for you at the office and after a few days the Address Card – Lakcímkártya will be mailed to you.
This small card is needed for almost everything and any kind of official business.