According to national regulations, 1 month, you can do the certification as many times as you want. Taxpayers can do the certification by stages according to the size of their business volume (it is suggested that after the declaration period is over, the staff of the tax service hall are busy accepting the declaration), or they can go to the automatic certification machine of the tax service hall for certification themselves, or they can do the certification every day. At the end of the month, you can print the certification result notice and the certification result list at one time.

The general practice in the industry is to put together the invoices received this month and get them certified by the tax bureau on the 25th of each month. If you receive the invoice after 25th, you can go to the tax bureau for certification.

Extended data:

Matters needing attention in VAT invoice authentication

1, fill in all items, and fill in all copies at one time. The content and amount of the two copies are the same.

2, clear handwriting, shall not be altered. If it is filled in incorrectly, a special invoice shall be issued separately, and the words "filled in incorrectly and invalid" shall be marked on the wrong special invoice. If the special invoice is invalid after being issued because the buyer did not ask for it, it should also be treated as an error.

3. Invoices and deduction forms shall be affixed with the special seal for unit invoices, and no other financial seals shall be affixed. According to the different versions of the special invoice, affix the special financial seal or invoice seal in the lower left corner or lower right corner of the special invoice to cover the column of "billing unit". The special seal for invoices uses red inkpad.

4. When taxpayers issue special invoices, they must affix the column of special invoice sales unit in advance. Don't fill in the column of "sales unit" manually. If it is filled in manually, it is a special invoice that is not issued according to the regulations, and the buyer shall not use it as a tax deduction certificate. Special invoice sales unit column is stamped with blue inkpad.

5. When issuing special invoices, the word "RMB" must be stamped before the total amount (in figures) in the columns of "Amount" and "Tax".

The names of the buyer and the seller must be filled in in detail and not abbreviated. If the company name is long, you can fill in the "Name" column in two lines, and if necessary, you can draw the upper and lower horizontal lines of the column.

6. If the goods are returned, the sales discount will receive the deduction coupons and invoices from the buyer.

7. In addition to the taxpayer's special financial seal, the special invoice issued by the tax authorities must also be stamped with the special VAT invoice issued by the tax authorities. The special seal is stamped in the middle of the bottom of the special invoice, using red inkpad. If the above seal is not affixed, the buyer shall not use it as a deduction voucher.

8. Special invoices shall not be issued for use.

References:

Baidu Encyclopedia-VAT Invoice