Portuguese invoice QR codes become mandatory from January 2022 with ATCUD codes optional

Portugal is introducing mandatory QR codes on invoices, starting from 1st January 2022 and has deferred mandatory inclusion of ATCUD codes (a document identification number) until 2023 making it an option to include on invoices from January 2022. This is a part of a bigger effort by the Portuguese government to simplify and modernize tax compliance and VAT.

Back in 2019, Portugal passed a mini e-invoicing reform consolidating the country’s framework around SAF-T reporting and certified billing software.

Since then, a lot has happened: non-resident companies were brought into the scope of e-invoicing requirements, deadlines have been postponed due to Covid, and new regulations were published. This blog summarises the latest and upcoming changes.

QR Code

Introduced in 2019, the de facto implementation of the QR code requirement was delayed and is now expected to be fully implemented in January 2022, from which point a QR code should be included in all invoices. Technical specifications about the content and placement of the code in the invoice are available on the tax authority’s website.

ATCUD – Unique ID and validation codes

The ATCUD is a unique ID number to be included in invoices and is part of the content of the QR code. The ATCUD is a number with the following format ATCUD: ‘Validation Code-Sequential number’.

To obtain the first part of the ATCUD – the so-called ‘validation code’, taxpayers must communicate the document series to the tax authority along with information such as type of document, first document number of the series, etc.

In return, the tax authority will deliver a validation code. The validation code will be valid for the whole document series for at least a fiscal year. The second part of the ATCUD – the ‘sequential number’ – is a sequential number within the document series.

To obtain a validation code, taxpayers must communicate the following data to the Portuguese tax authority:

  • The identification of the document series;
  • The type of document, following the document types established in the SAF-T (PT) data structure;
  • The starting number of the sequential number used within the series;
  • The date when the taxpayer is expected to start using the series to which a validation code is required;
  • Once approved, the tax authority creates a validation code with a minimum size of eight characters.

The Portuguese tax authority has published technical specifications for obtaining the validation code, creating a new web service. To access this web service, a specific certificate obtained from the tax authority is required.

In addition, the tax authority has created a standard list of document classes and types, enabling the communication of document types in a structured format.

An ATCUD is optional for inclusion on invoices from January 1st 2022 and is expected to become mandatory in 2023.  Tungsten has been receiving and sending compliant invoices for Portuguese buyers and suppliers for several years and will continue to enable the attachment of the legal tax invoice in the submission process. Customers will continue to benefit from standardised and validated electronic invoice processing.


To discuss Portugal or other compliant countries we serve including Germany, India, Mexico or the use of PEPPOL across EMEA contact our enrolment team.

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