On October 2nd 2019, the Portuguese Tax Authorities published the general guidelines for the new invoicing rules. These confirmed that even companies without a permanent establishment in Portugal who are established within the EU will be required to issue invoices using certified software, from 1st January 2021.
From 1st January 2020, this obligation also applies tocompanies without a permanent establishment in Portugal who are established outside the EU.
The Portuguese tax authorities will provide free, certified invoicing software directly on their website which can be used free of charge by any company. The implementing decree specifying the terms of use for the software, the frequency of invoice submissions and other details has not yet been published.