1.As a general rule, , they should be recorded in the order in which they are received, and in the settlement period in which they are to be deducted.
2.For the taxpayers who have the obligation to keep the Tax Register Books through the Electronic Headquarters, a specific deadline for submission is also established:
The information corresponding to the invoices received, must be provided within four calendar days from the date on which the invoice is registered in the accounts and, in any case, before the 16th day of the month following the settlement period in which the corresponding transactions have been included.
In the case of import operations, the four calendar days must be counted from the date of the accounting registration of the document containing the customs-cleared quota and in any case before the 16th day of the month following the end of the period to which the declaration in which they are included refers.
The deadline for sending the invoicing records corresponding to corrective incoming invoices shall be four calendar days from the date on which the invoice is issued or registered for accounting purposes, respectively.
However, in the event that the rectification determines an increase in the amount of the contributions initially deducted in accordance with the provisions of number 1.º of section Two of Article 114 of the Law on VAT, the deadline shall be that established for the registration of invoices received, i.e. four calendar days from the date on which the invoice is registered for accounting purposes and, in any case, before the 16th day of the month following the settlement period in which the corresponding transactions have been included.
Likewise, the deadline for remitting payments for transactions covered by the special cash basis regimewill be four calendar days after the corresponding payment is made.
For the purposes of calculating these four or eight calendar days, excludes Saturdays, Sundays and national holidays.
Please note that the Tax Agency's E-Office offers the tool "Deadline calculator for submitting invoicing records", which indicates the deadline for submitting these records, as well as the period and year for entry in the Invoice Receipts Register Book for each of the different invoice keys.