1. What Has Changed—and What is Proposed
1.1 QES deferred one year. The proposed State Budget for 2026 introduces a further one-year delay to the Qualified Electronic Signature (QES) requirement on PDF e-invoices. PDFs remain acceptable as e-invoices until 31 Dec 2026; from 1 Jan 2027 every PDF e-invoice must carry a QES issued by a certified trust service provider.
1.2 SAF-T (PT) Accounting moved to 2028 (draft). The annual SAF-T Accounting submission—originally tied to 2027 for 2026 transactions—is now proposed to take effect in 2028. This shifts the first mandatory accounting file submission out by one more year.
1.3 Parliamentary process and timing. The postponements are contained in Draft Law No. 37/XVII/1 (2026 Budget). Parliamentary debate has begun, with a final vote scheduled for 27 Nov 2025. Until the law is approved and published, the changes remain proposals; businesses should plan on the basis of this timeline while monitoring formal enactment.
2. Current e-Invoicing Status in Portugal (Legal Equivalence Remains)
2.1 PDF as e-invoice through 2026. Since earlier reforms, electronic invoices (including PDF) carry the same legal value as paper invoices. Under the draft 2026 Budget, that recognition continues through 31 Dec 2026; the QES attachment becomes mandatory starting 1 Jan 2027.
2.2 Security and integrity controls. Even without a QES in 2025–2026, issuers must maintain general controls over authenticity, integrity, and legibility of invoice data. From 2027, the QES will serve as the qualified mechanism to prove those properties on PDF e-invoices.
3. Non-resident VAT-registered Businesses: Three Obligations in Place Since 1 Jan 2023
3.1 Certified invoicing software with ATCUD. Invoices must be generated by certified software that can assign the ATCUD sequential validation code. ATCUD is an 8-character code presented as “ValidationCode-DocumentNumber”, allocated in batches via AT’s API and applied at issuance.
3.2 QR code on paper/PDF invoices. All paper or PDF invoices must include a QR code. The QR encodes key data—supplier TIN, ATCUD/UIDD, taxable amount, VAT, and the software certificate ID. (An EDI flow can bypass the QR if documents move in a structured standard format mapped to SAF-T fields.)
3.3 Monthly invoice reporting (SAF-T Billing). Non-residents must report invoices to the Autoridade Tributária (AT), typically by submitting the SAF-T (PT) Billing file. The due date is the 5th day of the month following the period. The file contains master data (products, customers, suppliers, tax table) and transaction data (sales/purchases, goods movements, payments). Reporting is limited to information readily available in the taxpayer’s accounting systems.
4. Understanding ATCUD, QR Code, and SAF-T Billing (Structure and Flow)
4.1 ATCUD mechanics.
- Allocation: Certified systems request batch validation codes from AT via API.
- Issuance: Each invoice receives a unique document number within the batch, forming the ATCUD printed on the document.
4.2 QR contents (core elements).
- Supplier TIN; ATCUD/UIDD; taxable base; VAT; software certificate number.
- Purpose: Fast capture by AT or buyers’ systems, reducing rekeying and fraud risk.
4.3 SAF-T Billing layout (high level).
- Master files: products; customers; suppliers; tax table.
- Transactions: invoices (sales/purchase), goods movements, payments.
- Transport: Submitted via AT interfaces/webservices; widely produced by certified billing providers.
5. Timeline at a Glance (Subject to Final Approval)
- 1 Jan 2023: Non-resident VAT-registered businesses aligned to resident rules (certified software + ATCUD; QR on paper/PDF; monthly SAF-T Billing).
- Through 31 Dec 2026: PDFs accepted as e-invoices without QES; maintain general integrity controls.
- 1 Jan 2027: QES required on every PDF e-invoice (QES issued by certified third-party providers).
- 2028: SAF-T (PT) Accounting submission becomes effective (per draft 2026 Budget).
- 27 Nov 2025: Final parliamentary vote on the 2026 Budget (which contains the postponements)
