E-invoicing is mandatory in Portugal for business-to-government (B2G) transactions. Suppliers must issue e-invoices to government entities in the CIUS-PT or CEFACT CIUS-PT format (both are based on XML) and submit them through the FE-AP platform. The Public Administration Shared Services Entity (Entidade de Serviços Partilhados da Administração Pública, or ESPAP) manages this platform and the implementation of e-invoicing and other shared services within the Portuguese public sector. 

E-invoices must include an electronic signature to ensure authenticity and must be archived for 10 years. 

Currently, e-invoicing for business-to-business (B2B) transactions in Portugal is not mandatory. However, the Portuguese Tax Authority requires resident and non-resident taxpayers to transmit invoice data electronically using certified invoicing software that can generate invoices with a unique document code (ATCUD) and a QR code. All resident taxpayers are also required to submit SAF-T reporting information on a monthly basis, including sales invoices. 

From January 1, 2026, businesses using PDF invoices for transactions not covered by the e-invoicing mandate must include a Qualified Electronic Signature or a Qualified Electronic Seal, issued by a certified third-party provider.

Businesses must include the following information in VAT invoices in Portugal: 

• Sequential invoice number

• Date of issue

• Supplier details, including tax identification number 

• Customer details, including tax identification number 

• Description and quantity of goods and/or services

• Unit price 

• Total amount 

• Applicable VAT rates and amounts

• ATCUD and QR code

In Portugal, the monthly submission of SAF-T files serves as a near real-time reporting mechanism. However, as Portugal is aligned with the European Union’s VAT in the Digital Age (ViDA) initiative, it may introduce further digital reporting obligations in the future.

Businesses operating in Portugal should stay informed about these developments to ensure ongoing compliance with evolving e-invoicing and VAT reporting requirements.

Failure to issue compliant e-invoices in Portugal can incur fines of €150–3,750. Using noncompliant e-invoicing software can result in fines of €3,000–18,750.