Tax residency of an individual is a key factor for determining tax obligations and the application of international double taxation avoidance agreements. Under Croatian law, a resident is a person who has a domicile or habitual abode in Croatia, with the precise determination of residency status governed by the provisions of the General Tax Act. The term “domicile” refers to the place where the individual owns or possesses an apartment for at least 183 days, while “habitual abode” refers to a stay that is not temporary, also lasting at least 183 days. When a taxpayer has a domicile or habitual abode in multiple countries, the rules of double taxation avoidance treaties apply, giving priority to the country where the taxpayer has their center of vital interests. The center of vital interests is determined by family, economic, cultural, and social ties, as well as other personal factors. If residency cannot be determined based on vital interests, habitual abode is considered, followed by citizenship. In cases where an individual holds dual citizenship or none, residency is established through mutual agreement between the countries. It is particularly important for Croatian residents to report all income earned abroad, regardless of whether taxes have already been paid on it. Foreign taxes can be credited against domestic tax liabilities, but only with appropriate documentation and confirmation from the foreign tax authority. The correct application of residency rules helps avoid double taxation and ensures compliance with tax obligations under Croatian law.