Fiscal residence tie breaker: permanent home, centre of vital interests, habitual abode, nationality, then mutual agreement. Residency under the Convention follows domestic taxation law; when an individual is resident of both Contracting States, residency is determined by: permanent home, then centre of vital interests, then habitual abode, then nationality, and finally by mutual agreement of competent authorities if previous tests are inconclusive. For persons other than individuals, residency if dual is determined by the place of effective management.