The process of determination of the residency status for tax purposes is regulated by the provisions of Article 4 of the Croatian Model of Tax Agreement for the avoidance of double taxation, provisions of the General Tax Act ​in force​ and the provisions of the Ordinance for the implementation of the General Tax Act in force.

According to the provisions of the Ordinance for the implementation of the General Tax Act in force the Questionnaires shall be completed in process of determination of the tax residency status of the individual. The Questionnaire TU shell be filled in when determining change of the residency status from non-resident to resident of the Republic of Croatia, while Questionnaire TI shell be filled in when determining change of the  residency status from resident to non-resident of the Republic of Croatia, respectively the Questionnaires shell be filled in all cases in which it is essential to determine the tax residency status of natural persons (registration with/deregistration from the Register of Tax Payers, processing of annual tax return, income tax returns, calculation, suspension and payment of income tax prepayments; certification and in situations where the competent tax authority determines the need for their filling).

The main purpose of the Questionnaires of residency (form attached: questionnaire TU and questionnaire TI) is to simplify the application of the procedure laid down in Article 4, paragraph 2 of the Croatian Model Agreement for the avoidance of double taxation (tie-breaker rules), respectively to uniformly and accurately determine the relationship, the tax residency, of the taxpayer with the Contracting State that will ultimately have the right to tax the taxpayer under the principle of world income (world income principle).

Source: Tax office