Fungible goods origin rules require physical segregation or compliant inventory methods, with recordkeeping to verify origin status. Fungible goods and materials are treated as originating either by physical segregation or, where commingled, by use of an inventory management method recognised under the generally accepted accounting principles of the Party where production takes place, provided the method is used consistently throughout the fiscal year. The method must distinguish originating from non-originating materials and ensure that no more goods or materials receive originating status than would have resulted from physical segregation. A producer using such a system must keep records sufficient for the competent authority to verify compliance.