If the seller fails to issue a special VAT invoice within the time limit stipulated by Pan Asia Nonferrous Metals Exchange, the seller shall be liable for breach of contract. Confirmation of the breaching party's breach of contract shall be subject to the written notice of breach of contract issued by Pan Asia Nonferrous Metals Exchange. The breaching party shall pay liquidated damages. Default amount = (invoiced tax amount-invoiced tax amount) ×20%.