Dual resident entities: treaty relief limited unless competent authorities agree on a single residency for tax purposes. The Convention defines resident by tax liability criteria and applies a sequential tiebreaker for individuals: permanent home, centre of vital interests, habitual abode, nationality, then mutual agreement. For persons other than individuals, the MLI replaces the Convention's rule and requires competent authorities to determine residency by mutual agreement considering place of effective management, place of incorporation or constitution and other relevant factors; absent agreement, treaty relief is not available except as the competent authorities may agree.