It is enough to offset the income that was not invoiced last month. The account should indicate which invoices are issued for income that has not yet been invoiced.

1. When the tax obligation is not invoiced, just fill in the positive sales amount in the column of "Unbilled Income" when declaring VAT, but you need to keep relevant evidence, such as contracts and collection records, for future verification.

2. If invoices are issued for the unbilled income in the future, during the invoicing period, the declared negative value-added tax will be filled in for the "unbilled income", and the system will start the abnormal comparison processing program, which needs to be reviewed in the lobby, and submit the accounting vouchers of the unbilled income obtained in the previous period and the invoices issued in this period as vouchers to apply for normal declaration, thus unlocking the tax control equipment.

If the certificate is insufficient or cannot be provided, you will not be able to declare the negative offset of the unbilled income in the current month; If the evidence is sufficient, but the reporting exception handling post cannot complete the audit on the spot due to a long time span or a large amount, the reporting exception handling post shall sign the Exception Comparison Transfer Sheet and transfer it to the processing post of the tax source management department for verification. If the tax source management department can lift the exception after handling the post verification, the taxpayer can declare normally and unlock the tax control equipment after signing the handover form for confirmation.