Are PDF invoices still valid in Portugal in 2026?

Yes. Law 73-A/2025 (2026 State Budget) extended the transitional regime: until 31/12/2026, PDF invoices are treated as electronic invoices for all tax purposes. From 01/01/2027, a plain PDF is no longer sufficient.

Does my foreign-owned company need certified invoicing software?

Almost certainly. Certification is mandatory for taxpayers with turnover above €50,000, anyone using invoicing software, or companies with organised accounts. Since 01/07/2021 it also covers non-resident businesses with a Portuguese VAT registration.

The Portuguese specification of the European e-invoicing standard EN 16931, using the UBL 2.1 or UN/CEFACT syntaxes. It is the format required in public procurement, delivered to central government via the FE-AP platform run by eSPap.

What are the penalties for non-compliance?

Late or missing invoice/series reporting (SAF-T, ATCUD): €200 to €10,000 (art. 117(9) RGIT). Not using certified invoicing software: €1,500 to €18,750 (art. 128(2) RGIT).

Could the 31/12/2026 deadline be postponed again?

It has been postponed every year since 2021, so another extension in the 2027 Budget is not impossible — but as of July 2026 none exists. Betting on a postponement is risky: implementation takes months.

E-Invoicing in Portugal 2026: Deadlines and Rules

E-Invoicing in Portugal 2026: Deadlines, Rules and How to Prepare

Portugal accepts PDF invoices as electronic invoices until 31/12/2026 (Law 73-A/2025). From 01/01/2027, e-invoices require a qualified electronic signature, qualified seal or EDI (art. 12, Decree-Law 28/2019), and SMEs must issue structured CIUS-PT invoices in public contracts. Non-resident companies with a Portuguese VAT number have needed certified invoicing software since 01/07/2021. Penalties range from €200–€10,000 (reporting) to €1,500–€18,750 (uncertified software).

By Hugo Ribeiro, Certified Accountant OCC no. 64356 · HVR Business Consulting · July 2026

What changes on 1 January 2027

Portugal's 2026 State Budget (Law 73-A/2025, of 30 December) extended the transitional regime one more year: until 31 December 2026, PDF invoices are "considered electronic invoices for all purposes of tax legislation". From 1 January 2027, two rules bite simultaneously:

Authenticity and integrity — e-invoices must carry a qualified electronic signature (QES), a qualified electronic seal, or travel via EDI (art. 12 of Decree-Law 28/2019). A plain PDF emailed to a client no longer qualifies.
B2G for SMEs — micro, small and medium companies must issue structured CIUS-PT e-invoices in public contracts. Their exemption was extended to 31/12/2026 by the 2026 Budget.

If you read guidance published before December 2025 saying "SMEs obliged from 01/01/2026" — it is outdated. The deadline moved.

Who is covered — the full timeline

Date	Obligation	Who
01/01/2021	CIUS-PT e-invoicing in public contracts (DL 111-B/2017, art. 9)	Large companies
01/01/2022	QR code on all invoices and tax-relevant documents	All issuers
01/01/2023	ATCUD code mandatory on all documents	All issuers
Since 2023	Monthly SAF-T invoice reporting by the 5th of the following month	All taxable persons
31/12/2026	End of PDF acceptance as e-invoice (Law 73-A/2025)	Everyone
01/01/2027	QES/seal/EDI required + structured B2G for SMEs	SMEs and public co-contractors
2028	Accounting SAF-T (IES annexes A and I), for 2027 periods onwards	Companies with organised accounts

CIUS-PT and EN 16931: the structured format

A true e-invoice is not a PDF — it is a machine-readable file. Portugal uses CIUS-PT, the national specification of the European standard EN 16931, in UBL 2.1 or UN/CEFACT syntax. Invoices to central government flow through the FE-AP platform (run by eSPap) — via WebServices/AS2 for volume, or a Microportal for businesses issuing under 250 invoices per year to the State.

Qualified signatures: the end of the plain PDF

From 01/01/2027, a B2B invoice in PDF only counts as an electronic invoice if authenticity and integrity are guaranteed by one of three routes: a qualified electronic signature, a qualified electronic seal (the corporate equivalent, ideal for automated bulk issuing), or EDI under an agreement guaranteeing authenticity and integrity. For most companies, the practical answer is invoicing software that applies a qualified seal automatically.

Special notes for foreign-owned companies

Non-resident VAT registrations — since 01/07/2021, non-resident businesses registered for VAT in Portugal must use AT-certified invoicing software. Foreign ERP invoices alone do not comply.
Certified software thresholds — mandatory with turnover above €50,000, whenever invoicing software is used, or with organised accounts (art. 123(8)-(9) of the Corporate Tax Code + Ordinance 363/2010). In practice, virtually every company qualifies.
Monthly SAF-T — invoice data must reach the tax authority by the 5th of the following month. Group reporting calendars set abroad rarely align with this; your Portuguese accountant must own it.
Fiscal representation — non-EU entities needing a fiscal representative: HVR coordinates this through a specialised partner (partner fee €200–350/year).

5-step readiness checklist

Audit your invoicing stack (Jul–Aug) — is it AT-certified? Does it export CIUS-PT and support qualified seals?
Fix ATCUD and series (Aug) — every document series pre-registered with the AT, QR codes on all documents.
Automate monthly SAF-T (Sep) — filing by the 5th, every month, owned by your accountant.
Contract the qualified certificate (Oct–Nov) — qualified seal or QES from an accredited provider, integrated into issuing. Selling to the State? Test FE-AP submission.
Run a live test (Dec) — issue signed test invoices and validate reception with key clients before year-end.

Penalties

Infringement	Legal basis (RGIT)	Fine
Missing/late invoice or series reporting	Art. 117(9)	€200 – €10,000
Not using certified invoicing software	Art. 128(2)	€1,500 – €18,750
Using non-compliant software	Art. 128(3)	€1,500 – €18,750

Non-compliant invoices can also jeopardise your customers' VAT deduction — a commercial problem, not just a tax one.

How HVR gets you compliant

HVR Business Consulting, founded in 2014 and based in Parque das Nações, Lisbon, serves 200+ clients — many foreign-owned. Hugo Ribeiro has been a certified accountant (OCC no. 64356) since 2000. E-invoicing readiness is built into our accounting plans from €150/month (€150/€300/€600 by company size — see pricing): compliance diagnosis, migration to certified software, ATCUD series management and guaranteed monthly SAF-T filing, all handled in English.

Request a free e-invoicing compliance check →

Frequently asked questions

Are PDF invoices still valid in 2026?

Yes, until 31/12/2026 (Law 73-A/2025). From 01/01/2027 they need a qualified signature, seal or EDI.

What changes on 1 January 2027?

Qualified signature/seal/EDI becomes mandatory for e-invoices, and SMEs must issue structured CIUS-PT invoices in public contracts.

Does my foreign-owned company need certified software?

Almost certainly — the obligation covers turnover above €50,000, any use of invoicing software, organised accounts, and non-resident VAT registrations (since 01/07/2021).

What is CIUS-PT?

Portugal's specification of EN 16931 for structured e-invoices (UBL 2.1 or UN/CEFACT), submitted to central government via the FE-AP platform.

What are the penalties?

€200–€10,000 for reporting failures (art. 117(9) RGIT); €1,500–€18,750 for uncertified software (art. 128(2) RGIT).

Could the deadline slip again?

Possibly — it has slipped since 2021 — but no postponement exists today, and implementation takes months. Prepare as if 01/01/2027 is final.