There is no relevant policy document stipulating that invoices must be issued within days after the business occurs, but it is recommended that invoices be issued as soon as possible after the business occurs. According to relevant laws and regulations, in case of any of the following circumstances in violation of the provisions of these Measures, the tax authority shall order correction and may impose a fine of less than 10000 yuan; The illegal gains shall be confiscated:
 （1） Failing to issue an invoice when it should be issued, or failing to issue an invoice in one time in all copies according to the specified time limit, order and column, or failing to affix the special seal for invoice;
 （2） Using a tax control device to issue invoices and failing to submit the invoice data to the competent tax authority on schedule;
 （3） Using non tax controlled electronic devices to issue invoices, failing to report the software program description materials used by non tax controlled electronic devices to the competent tax authority for filing, or failing to preserve and submit the data of invoicing according to regulations;
 （4） The invoice is used in a separate copy;
 （5） Expanding the scope of invoice use;
 （6） Using other vouchers instead of invoices;
 （7） Issuing invoices across specified regions;
 （8） Failing to hand in invoices for cancellation as required;
 （9） Failing to store and keep invoices according to regulations.
 What if the hotel refuses to issue an invoice?
 If the hotel refuses to issue invoices, it can complain and report to the tax department. According to the relevant laws and regulations, those who fail to issue invoices in accordance with the regulations and violate the relevant regulations on invoice management shall be ordered by the tax authorities to correct within a time limit, their illegal income shall be confiscated, and they may also be fined less than 10000 yuan. Issuing invoice is the legal obligation of the operator. The operator must provide shopping vouchers or official invoices for consumers. If the operator violates this legal obligation, it will bear the corresponding legal responsibility. To sum up, there is no relevant regulation on how long invoices should be issued, and it is better to issue invoices as soon as possible after business occurs. If the merchant refuses to issue the invoice, it can call the relevant inspection department to complain. Article 35 of the Measures of the People's Republic of China for Invoice Management, in case of any of the following circumstances in violation of the provisions of these Measures, the tax authorities shall order correction and may impose a fine of less than 10000 yuan; The illegal gains shall be confiscated:
 （1） Failing to issue an invoice when it should be issued, or failing to issue an invoice in one time in all copies according to the specified time limit, order and column, or failing to affix the special seal for invoice;
 （2） Using a tax control device to issue invoices and failing to submit the invoice data to the competent tax authority on schedule;
 （3） Using non tax controlled electronic devices to issue invoices, failing to report the software program description materials used by non tax controlled electronic devices to the competent tax authority for filing, or failing to preserve and submit the data of invoicing according to regulations;
 （4） The invoice is used in a separate copy;
 （5） Expanding the scope of invoice use;
 （6） Using other vouchers instead of invoices;
 （7） Issuing invoices across specified regions;
 （8） Failing to hand in invoices for cancellation as required;
 （9） Failing to store and keep invoices according to regulations.