online channels. Online self-service channels support the issuance of proof of transaction information, proof of account settlement and application for transaction details. Online self-help channels of CCB include "China Construction Bank Customer Service" WeChat WeChat official account, "China Construction Bank Pocket Branch" WeChat applet, "Longka Credit Card" WeChat applet, mobile banking, online banking, etc. Open the mobile phone WeChat, query WeChat WeChat official account about "CCB" through the plus sign in the upper right corner, and click the transaction details to view or print the electronic credit card limit certificate.