E-invoicing compliance and regulatory updates - Portugal

Electronic Invoicing in Portugal

Is e-invoicing mandatory in Portugal ?

E-invoicing is mandatory for B2G transactions. All public entities have been required to receive e-invoices since April 2019. For B2B transactions, e-invoicing is voluntary; however, invoices must be created using certified software and include ATCUD and QR codes.

Who is affected?

All Portuguese public bodies must be able to receive e-invoices. All suppliers must issue B2G-invoices as e-invoices.

Compliance requirements

Invoices must be issued using AT-certified software and include both ATCUD and QR codes. For B2G transactions, invoices are sent via the FE-AP platform or other approved portals. The invoice format must be compliant with CIUS-PT

Want to learn more about e-Invoicing compliance?

Download our Global e-invoicing and Tax Compliance fact sheet here for more information.

Key Deadlines 

• January 1st, 2027: Qualified electronic signatures(QES)mandatory in e-invoicing.

Standards & Platforms  

Platform

Invoices must be issued using AT-certified billing software.

In B2G transactions, e-invoices must be sent through the public administration platform FE-AP (Fatura Eletrónica na Administração Pública) or other portals available to the Tax and Customs Authority (AT).

What formats are required in Portugal?

B2G-invoices must be compliant with the CIUS-PT format.

Archiving in Portugal

What are the archiving requirements in Portugal?

Invoices must be archived for 10 years. Digital archiving is permitted within Portugal or the EU.Archiving outside the EU requires prior approval. Invoices must remain readable and maintain integrity and authenticity throughout the archiving period.

Legal invoice

For suppliers: A legal invoice is one issued using AT-certified software. It must include a QR code and ATCUD and, from 2026, a qualified electronic signature.

For buyers: A legal invoice is one received with ATCUD and QR codes and must meet authenticity and integrity requirements.

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Key Actions  

• Ensure compliance – Prepare for the 2027 signature requirement by selecting a qualified service provider.
• Archive properly – Retain invoices for 10 years in a format that guarantees accessibility, readability, and data integrity.

Portuguese e-invoicing and archiving requirements at a glance:

Supplier requirement: Invoices must be issued using certified software and contain a ATCUD as well as a QR code. B2G-invoices must be in CIUS-PT format and transferred using dedicated portals.

Buyer requirement: Authenticity, integrity and readability must be ensured..

Archiving requirement: Invoices must be stored for 10 years, ensuring accessibility, readability, and data integrity.