Residence tie breaker rules determine tax domicile by permanent home, centre of vital interests, habitual abode, nationality, or mutual agreement. Article 4 defines tax residence by reference to each Contracting State's domestic law and sets hierarchical tie breaker rules for dual residencies: for individuals-permanent home, centre of vital interests, habitual abode, nationality, then mutual agreement by competent authorities; for non individuals-the place of effective management determines treaty residence.