Assistance in Collection enables cross-border tax recovery with specified cost allocation and legal limits, including interim conservatory measures. Contracting States shall assist each other in collecting taxes finally determined by the requesting State, with the requested State collecting under its own laws and as if the tax were its own; requests must include required certificates. Where claims are under appeal, interim conservatory measures may be sought and, if accepted, applied as if the taxes were the requested State's own. Amounts recovered are promptly remitted to the requesting State minus agreed extraordinary costs. Ordinary costs are borne by the assisting State, extraordinary costs by the requesting State, and assistance is limited by domestic law, public policy, prior reasonable recovery efforts, and disproportionate administrative burden.