E-invoicing in Portugal.

The story

B2G e-invoicing has applied to large companies (over 250 employees or turnover above €50 million) since 2021, and to SMEs and micro-enterprises since January 1, 2026, after earlier postponements from an original 2022 target. Invoices use the CIUS-PT format, based on both UBL 2.1 and UN/CEFACT implementations of the EN 16931 standard, submitted through the FE-AP portal run by ESPAP, Portugal's Peppol Authority. Peppol BIS Billing 3.0 is also accepted as a transmission channel.

No general B2B or B2C e-invoicing mandate exists. A business may send a private buyer a structured e-invoice with that buyer's acceptance; paper and PDF remain valid by default. Separately, every invoice regardless of format must come from AT-certified billing software, carry a unique ATCUD document code (mandatory since January 1, 2023) and a QR code (mandatory since 2022), and be reported monthly through SAF-T (PT) Billing. These rules apply to Portuguese businesses and to non-resident companies with a Portuguese VAT registration.

PDF invoices remain valid without a qualified electronic signature (QES) until December 31, 2026. From January 1, 2027, a PDF invoice in B2B or B2C requires a QES unless a certified EDI model or another accepted structured format, such as CIUS-PT, is used.

Reported penalties under Portugal's General Tax Infraction Regime (RGIT) are €3,000 to €18,750 for using non-certified invoicing software, €750 to €22,500 for missing or incorrect mandatory invoice content (such as ATCUD or the QR code), and €150 to €3,750 for failing to issue a compliant B2G e-invoice. These figures are drawn from tax-compliance sources and have not been independently verified against the official Diário da República text.