Assistance in collection of tax claims enables cross-border enforcement and conservancy measures under domestic law of requested State. Assistance between Contracting Parties enables acceptance for collection or conservancy of tax claims-including interest, penalties and collection costs-by the requested Party, which shall apply its domestic enforcement and conservancy laws as if the claim were its own. Requests must be made by competent authorities with identification of the person, nature and elements of the claim, assets available, a declaration that the claim is covered, an enforcement instrument from the requesting State, and any other documents required. Assistance is limited by domestic law, public policy and proportionality considerations, and disputes on existence, validity or amount remain for the requesting Party's tribunals.