Invalid invoices should not be sent to the tax bureau. They should be kept separately or attached with correctly issued invoices.

When the general taxpayer issues an invoice, sales return and invoicing errors occur in the month, and the returned invoice and deduction meet the conditions for invalidation, it will be invalidated; If an error is found during issuance, it can be invalidated immediately. Invalid qualification refers to meeting the following conditions at the same time:

1. The collection and deduction time of the returned invoice does not exceed the month when the seller issues the invoice;

2. The seller did not copy the tax and did not keep accounts;

3. The purchaser is not authenticated or the authentication result is "taxpayer identification number is not authenticated" or "special invoice code and number are not authenticated".