According to the "Measures for the Administration of Catering Service Licenses" of the Ministry of Health, if a catering service provider needs to extend the catering service license, it shall submit a written application for extension to the original issuing department 30 days before the expiration of the validity period of the catering service license. If an application for extension is filed within the time limit, it shall be handled in accordance with the newly applied "Catering Service Permit". To apply for extension of catering service license, the following materials shall be provided: (1) an application for extension of catering service license; (2) A copy of the original catering service license; (three) the original "catering service license" business premises, layout technology, health facilities and other contents have changed or not changed; (4) Other materials prescribed by the food and drug supervision and administration departments of provinces, autonomous regions and municipalities directly under the Central Government. Health supervisors are not obliged to inform operators in advance because there is no legal provision. According to the "Measures for the Administration of Catering Service Licenses" of the Ministry of Health, if a catering service provider needs to extend the catering service license, it shall submit a written application for extension to the original issuing department 30 days before the expiration of the validity period of the catering service license. If an application for extension is filed within the time limit, it shall be handled in accordance with the newly applied "Catering Service Permit". To apply for extension of catering service license, the following materials shall be provided: (1) an application for extension of catering service license; (2) A copy of the original catering service license; (three) the original "catering service license" business premises, layout technology, health facilities and other contents have changed or not changed; (4) Other materials prescribed by the food and drug supervision and administration departments of provinces, autonomous regions and municipalities directly under the Central Government. Health supervisors are not obliged to inform operators in advance because there is no legal provision.