Assistance in tax collection allows one state to collect or conserve another state's revenue claims under its domestic enforcement rules. Contracting States shall mutually assist in collecting or conserving revenue claims-including taxes, interest, penalties and collection costs-on request by a competent authority. The assisting State shall collect or take conservatory measures under its own domestic laws as if the claim were its own, without granting special time limits or cross-border priority. Courts or administrative bodies of the assisting State may not determine the existence, validity or amount of the requesting State's claim. Requests may be suspended or withdrawn if the claim ceases to meet the statutory conditions, and assistance is subject to exceptions for domestic law, public policy, failure to pursue reasonable measures, or disproportionate administrative burden.