For tax cancellation, digital certificates are usually used for electronic authentication. CA certificate, also known as digital certification authority, is a digital identity certificate issued by an authoritative third party. In the process of tax cancellation, the use of CA certificate can ensure the safety and credibility of data, and prevent identity from being fraudulently used and data from being tampered with. Therefore, in general, you need to use CA certificate to handle tax cancellation procedures. For specific procedures and requirements, you can consult the local tax authorities or tax agencies to ensure compliance with relevant laws and regulations.