The change in the deadline was formalised by the Secretary of State for Tax Affairs, Cláudia Reis Duarte, in a decree signed on December 22 and subsequently published on the Finance Portal.

Under normal circumstances, the deadline for submitting December's billing data to the Federal Revenue Service would be January 5, 2026.

However, since this "will correspond to the second business day after the New Year's festivities," taxpayers required to submit the data will have four more days to fulfil their tax obligation, according to the official statement.

"The communication of invoices referred to in paragraphs 1 and 2 of article 3 of Decree-Law No. 198/2012, of August 24, relating to the month of December of the current year" may be made, "without any surcharges or penalties, until January 9, 2026," says the statement.

The Secretary of State, who oversees the tax are, justifies the extension with the need to "allow the best conditions for the fulfilment of tax obligations, in order to ensure the quality of the reported information."

According to the decree that regulates the rules for sending this data through SAF-T files, the usual deadline for companies to send "the details of invoices issued under the VAT Code" and "the details of documents that allow the verification of goods or services and receipts" to the Tax Authority's website is the 5th of the month following the month in which the invoices were issued.