1. food business license: this is a necessary certificate for sellers engaged in food business. It is necessary to apply to the local food and drug administration and provide relevant supporting materials, such as identity cards and housing lease contracts.

2. Health certificate: This is the certificate that the seller needs to apply for, and he needs to apply to the local health department for physical examination and provide relevant supporting materials.

3. Business license: If you conduct business activities at home, you need to obtain a business license. The business license is a proof that you are registered in a government agency and ready to conduct business activities.

4. Tax registration certificate: Those who have income from selling jiaozi at home need to apply for a tax registration certificate with the tax authorities.

It should be noted that different regions and different types of sales channels may require different certificates, so it is recommended that you consult local government agencies or lawyers for more detailed information before handling certificates. At the same time, in order to ensure the quality and safety of food, sellers also need to abide by relevant food safety laws and regulations.