hello, dear, it's my pleasure to answer your questions. Where is the check code of the catering invoice? The check code can be found on the website of the local State Taxation Bureau on the left side of the invoice. In the "Invoice Public Inquiry" window, enter the invoice code to query the 21-digit check code of the invoice and check the authenticity of the invoice. Note: Since the launch of the new version of ordinary invoices in 2112, the national tax authorities have given consumers a "new ID number" for each ordinary invoice, that is, a 21-digit "check code or tax control code". The 21-digit check code is located above the name of the invoice customer. The check code of each invoice is a unique number automatically generated by the invoice management system when the taxpayer issues an invoice. Consumers can use the "check code or tax control code" to query the invoice face information and distinguish the authenticity of the invoice.