Within three months. According to Blog Park, the WeChat certificate can be used within three months of expiration. The WeChat certificate is issued by the electronic certification service agency established by the relevant state departments in accordance with the "Electronic Signature Law of the People's Republic of China" to represent the enterprise. Or a personal online legal identity and a legal tool used to implement electronic signatures, which is equivalent to the company's ID card and the company's official seal, commonly known as "digital certificate".