The Shanghai health code shows that it will be cancelled after a few days in Shanghai.

Five days. According to the relevant information of the health code, the Shanghai health code shows that the record of returning to Shanghai in five days will be automatically cancelled, because the record of five days should be kept to screen the secret connection. Shanghai health code is called Shen Sui code. Applying for codes is one of the important measures for the fine management of Shanghai megacities. The application code supports the dynamic management of green, yellow and red, and will serve as the life service code of Shanghai citizens. This application provides convenient services for Shanghai residents. According to the needs of epidemic prevention and control in COVID-19, the application code has three colors of dynamic management: green code, yellow code and red team.