According to the Detailed Rules for the Implementation of the Regulations of the People's Republic of China on Resident Identity Cards:
Thirty-first returned identity cards shall be recorded by the household registration authority and properly kept. Certificates that have expired will be considered invalid.
Thirty-second invalid identity cards, the household registration authority will cut off part of the seal of the issuing authority, and make a destruction list, which will be destroyed by the issuing authority regularly.