If you became a tax resident of Slovenia in the past and now you are leaving, it is important, account of the determination of your residency status, to notify the Financial Administration. To do so, you can either go to the local offices of the Financial Administration and fill in the questionnaire Application for determining an individual's residency status under the Personal Income Tax Act (Zdoh-2) - leaving the Republic of Slovenia, or you can download the questionnaire from the previously mentioned link.
The questionnaire is not mandatory, you can simply file an application for the determination of your residency status. In case you are leaving for a short period of time (less than six months and you still have residential ties with Slovenia, such as a home, which is available on a permanent basis, family, etc.) you will stay a slovenian resident and you will be taxed according to the worldwide income. If you are, on the other hand, planning to go abroad for a longer period of time (more than six months) and you will also move the center of your economic and personal interests to that country, you will be considered as a non resident of Slovenia and you will only be liable to pay taxes from income with slovenian source.
More information can be found in Section Details.