The confirming letter of credit may offer the beneficiary double safeguard on payment of price. Three prerequisites shall be met when deciding whether there is confirming letter of credit under UCP 600, namely, the explicit authorization of the issuing bank, agreement to confirm by the confirming bank, and no precedent conditions which may endanger the independence and irrevocability of letter of credit. If there is no explicit authorization from the issuing bank, the confirmation by the confirming bank is so called silent confirmation. The agreement to confirm by the confirming bank shall be in writing. In case the bank authorized to confirm refuses to add its confirmation but fails to notify the issuing bank, the beneficiary shall not hold the bank authorized to confirm liable for the confirmation obligations. After adding its confirmation, if the confirming bank refuses to extend its confirmation to the amendment of the letter of credit, it shall notify the beneficiary in its advice. Otherwise, the confirmation shall be deemed to have been extended to the amendment. The confirming bank may add precedent conditions when adding its confirmation to the letter of credit. However, such precedent conditions shall not endanger the independence and irrevocability of letter of credit.