Cross-border tax collection assistance: Contracting States may collect or conserv conservatory measures for defined revenue claims. Article 26A requires Contracting States to assist in collection of defined revenue claims, including certain national taxes, interest, penalties and collection costs. Where a claim is enforceable or eligible for conservancy in the requesting State, the requested State shall accept it for collection or conservancy and apply its domestic enforcement rules as if it were its own claim, with acts that suspend limitation periods having corresponding effect. Assistance is subject to domestic law limits, public policy, prior reasonable collection efforts and proportionality of administrative burden.