If you are living in Sweden and you have been registered in the Swedish population register and you are planning to move abroad for a year or more, you should notify the Swedish Tax Agency of your move.
The above applies to international students with Swedish Personal Identity Number (personnummer) who are moving from Sweden and this applies also to Swedish and International students who are moving abroad to study more than one year.
You can notify the Swedish Tax Agency of your move by filling one of the forms below:
Moving Abroad, Notification, SKV 7665, English version
Anmälan - Flyttning till utlandet
For more information about this rule you can read: