Electronic invoice in Portugal

The Definitive Guide to Portugal’s E-Invoicing Landscape: Navigating the dual circuits of B2G CIUS-PT delivery via eSPap and separate AT fiscal compliance (ATCUD, SAF-T).

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Overview

Portugal is easy to get wrong because two entirely separate regimes run at the same time and are constantly confused with each other. One is public procurement e-invoicing: structured CIUS-PT invoices to public buyers, now mandatory for every category of supplier since 1 January 2026. The other is fiscal control of invoicing generally: certified software, pre-registered document series, ATCUD, QR codes and monthly transmission of invoice data to the tax authority.

Peppol handles the first and does nothing at all for the second. That is the single most expensive misunderstanding available in this market — see The two circuits. Note also that Portugal is not a clearance country: the tax authority receives invoice data after issuance, it does not authorise invoices before they reach the buyer.

EAS 9946

the Portuguese VAT number (NIF) is the national Peppol address scheme

ATCUD + QR

on every fiscally relevant document produced by certified software

10 years

retention — and storage outside the EU needs the tax authority's permission

Timeline

Portugal has postponed more deadlines than almost any other EU country, and did so again in the 2026 State Budget. Reading a Portuguese roadmap without checking the latest budget law is a reliable way to be wrong.

Already in force

18 April 2019 and 18 April 2020

Public buyers must receive e-invoices

Central contracting authorities from April 2019, other public buyers from April 2020, under the Public Contracts Code (Código dos Contratos Públicos, CCP).

1 January 2021

Large suppliers must issue structured B2G invoices

Suppliers other than SMEs move to mandatory structured invoicing on public contracts.

1 January 2022 and 1 January 2023

QR code, then ATCUD

The QR code requirement takes effect for documents issued by certified software, followed a year later by the ATCUD unique document code. See Fiscal controls and AT reporting.

1 January 2026

The B2G transition period ends

The relief for micro, small and medium enterprises and for public bodies acting as suppliers expired on 31 December 2025. Structured CIUS-PT is now required from all main supplier categories on public contracts.

Still ahead

1 January 2027

The PDF concession ends

PDF invoices are accepted as electronic invoices for tax purposes only until 31 December 2026. From 2027 an electronic invoice needs a qualified electronic signature — or one of the alternatives set out under B2B, B2C and the PDF.

2028 — for FY 2027

SAF-T Accounting becomes mandatory

Deferred again by the 2026 State Budget. The first mandatory annual SAF-T Accounting file covers FY 2027 transactions and is filed in 2028. This is separate from SAF-T Billing, which is already monthly.

1 July 2030

ViDA digital reporting for intra-EU B2B

Structured e-invoicing and near-real-time reporting for the cross-border transactions in scope. See ViDA and 2030.

The PDF extension does not apply to B2G. Much commentary reports that "small companies may keep issuing PDFs until the end of 2026" and leaves it there. That concession is about PDFs counting as electronic invoices for tax purposes. It does not suspend the structured CIUS-PT requirement on public contracts, which has applied to all main supplier categories since 1 January 2026.

The two circuits

Everything in Portugal becomes clearer once you accept that there are two independent obligations with different owners, different technology and different regulators.

B2G delivery

Getting a structured CIUS-PT invoice to a public buyer, through FE-AP, Peppol, a direct AS2 or API connection, a portal or a service provider.

Governed by eSPap. This is what an Access Point does.

Fiscal compliance

Certified software, document series registered in advance, ATCUD, QR codes, invoice data to the tax authority, retention and audit trail.

Governed by AT. This is not what an Access Point does.

The consequence for scoping: tax reporting to the AT is not performed automatically by the Peppol exchange and has to be organised separately. And the legal obligation towards the AT stays with the taxpayer even where a provider performs the technical work.

Who is in scope

Suppliers on public contractsMust issue structured electronic invoices. Exceptions exist for secret contracts and contracts whose performance requires special security measures

Public buyersMust be able to receive and process e-invoices

Domestic B2B and B2CNo general structured e-invoicing mandate. Ordinary fiscal rules still apply in full

Anyone with Portuguese VAT obligationsMust transmit invoice data to the AT — including non-residents registered for Portuguese VAT

A drafting point worth noticing: the CCP wording is about the performance of public contracts generally, not about the EU procurement thresholds. Compliance should be assessed against Portuguese national law rather than by asking whether a contract exceeds a European threshold.

B2G and FE-AP

FE-AP — Fatura Eletrónica na Administração Pública — is the government e-invoicing system, and eSPap describes its portal as the gateway of the State for receiving invoices and corrective documents electronically. It supports direct connection by suppliers and service providers, and its official guidance covers AS2 over HTTPS, web services and APIs, asynchronous status messages, separate pre-production and production environments, onboarding and integration testing.

The competence sits on a clear legal footing: Decreto-Lei n.º 123/2018 of 28 December gave eSPap the power to issue the technical and functional requirements supporting e-invoicing, to develop support instruments for the entities covered, and to provide the reception solution.

Peppol components are used within the FE-AP infrastructure, but the legislation does not require every B2G invoice to travel exclusively over a Peppol four-corner exchange. In practice the channel is agreed with the individual public buyer: FE-AP, Peppol, a direct AS2 or API connection, that institution's portal, or its service provider.

FE-AP onboarding is not Peppol certification

Direct integration with FE-AP is its own process: an onboarding questionnaire, selection of the communication channel, pre-production setup, tests of successful and failing invoices, credit notes and debit notes, status message testing, retesting in production, and documents evidencing the organisation's identity. Treat it as the technical and contractual onboarding of a specific government gateway — not as a national accreditation.

B2B, B2C and the PDF

There is no general requirement for Portuguese companies to exchange structured XML in domestic B2B or B2C. The rule that dominates practice is the PDF concession — and it has now been extended so many times that its expiry is treated with justified scepticism.

Until 31 December 2026A PDF invoice is recognised as an electronic invoice for tax purposes. The 2026 State Budget extended the transitional rule again

From 1 January 2027A plain PDF loses that automatic recognition unless the legislature extends it once more

In B2GThe concession never applied. Structured CIUS-PT has been required from all main supplier categories since 1 January 2026

What actually replaces the PDF

Most coverage says "qualified electronic signature from 2027" and stops. The law is wider: authenticity of origin and integrity of content may be ensured by a qualified electronic signature, a qualified electronic seal, or EDI under the European Model EDI Agreement. A qualified signature is one route, not the only one — which matters if signing per document is awkward in your architecture.

The general rules also continue to require the recipient's agreement to the electronic format, and the mandatory invoice content is unaffected by any of this.

The model

Portugal is best classified as post-issuance centralised tax reporting with fiscal invoice controls — not clearance, and not a Peppol five-corner model either.

The supplier issues the invoice without prior authorisation from the AT

The AT assigns no clearance number after checking the content

The document does not have to pass through the AT before reaching the buyer

What does happen is that data on issued invoices reaches the AT afterwards, and that documents carry pre-registered series, an ATCUD and, where applicable, a QR code. Tax reporting exists independently of the transport channel used for the commercial exchange — which is why choosing Peppol answers a delivery question and no fiscal one.

Fiscal controls and AT reporting

Document series and ATCUD

Every document series must be notified to the AT in advance. On registering the series the AT issues a validation code, which is combined with the sequential document number to form the ATCUD (Código Único de Documento). The ATCUD must appear on invoices and other fiscally relevant documents and is generated at the moment of issue. It has been required since 1 January 2023.

QR code

Required on the relevant documents produced by software certified by the AT, since 1 January 2022. ATCUD and QR are fiscal controls on the document — they are not prior clearance of its content, and they do not make Portugal a clearance jurisdiction.

Transmitting invoice data

Anyone subject to the Portuguese invoicing rules and carrying out VAT-taxable transactions in Portugal must transmit invoice data to the AT. Three routes are permitted:

—Real-time transmission through the API

—Upload of the structured SAF-T (PT) billing file

—Manual entry in the Portal das Finanças

The deadline is the 5th day of the month following the month of issue. So Portugal does not have mandatory real-time reporting in the strict sense — the real-time API is one permitted channel, and the obligation can equally be met by a monthly SAF-T (PT) submission.

e-Fatura

The e-Fatura portal is how the tax administration receives and matches invoice data, particularly in B2C. It is not a universal platform for delivering the legal invoice from seller to buyer — it is tax reporting and data control infrastructure, and treating it as a delivery channel is a category error.

Keep the two SAF-T files apart. SAF-T Billing is the monthly file covering invoices issued. SAF-T Accounting is the annual accounting file, deferred again by the 2026 State Budget — the first mandatory submission covers FY 2027 and is filed in 2028.

Formats

Portaria n.º 289/2019 assigns the governance model for public e-invoicing to eSPap and requires the Portuguese government model to conform to EN 16931 and Directive 2014/55/EU. The national specification is CIUS-PT, which carries the Portuguese semantic rules, mandatory business terms, identifiers, tax details and validation rules.

Invoices and debit notesOASIS UBL 2.1 Invoice, per the eSPap technical guidance for the direct FE-AP interface

Credit notesOASIS UBL 2.1 CreditNote

ValidationXSD and Schematron validation of CIUS-PT, plus additional FE-AP business rules

CIIThe European Commission country profile lists UN/CEFACT CII CIUS-PT as well — but the direct FE-AP interface documentation is built unambiguously around UBL 2.1

The safe production choice

Build on UBL 2.1 CIUS-PT. Where CII is required, confirm support with the specific public recipient or its service provider before committing — the profile being listed at European level is not a guarantee that a particular Portuguese gateway will accept it.

Identifiers

The confirmed Portugal-specific Peppol scheme is 9946 — Portugal VAT number. A participant is normally identified by its Portuguese NIF. Other global schemes such as GLN can technically be used in Peppol, but 9946 is the national one.

The practical form depends on SMP and Access Point configuration, so at onboarding check three things rather than assuming: whether the PT prefix is expected, which participant identifier the recipient has actually registered, and which document types and process identifiers are published in its SMP. A correct NIF in the wrong shape fails as completely as a wrong NIF.

Peppol and eSPap

The Portuguese Peppol Authority is eSPap — Entidade de Serviços Partilhados da Administração Pública, I.P. The division of responsibility with the tax authority is clean and worth memorising:

eSPapPublic sector e-invoicing, interoperability and Peppol governance

ATVAT, ATCUD, SAF-T (PT), e-Fatura and fiscal control

Peppol is used, but it is not the sole mandatory national channel. It is part of the government interoperability landscape rather than a legal requirement for every B2G invoice.

Requirements for providers

No separate national licence comparable to the Slovak digitálny poštár or the French plateforme agréée was identified in the official sources. eSPap is listed by OpenPeppol as the Portuguese Peppol Authority, but no public rules establishing a licensing layer for all Access Points on the Portuguese market were found. That does not release a provider from the general OpenPeppol requirements or from the rules of the specific FE-AP channel.

A certified Access Point from another country can serve Portuguese clients — the country of registration does not limit where Peppol services may be provided

No requirement was found for a Portuguese legal entity, an office or servers in Portugal, a corporate representative, a local official mailbox or a local bank account

Separate VAT registration or fiscal representative requirements may arise for the taxpayer, particularly a non-EU business — but that is not a condition of Access Point status

What the provider does need

—A valid Peppol-certified Service Provider status, applicable Peppol BIS profiles and AS4

—Correct registration of participant identifiers and endpoints, with the Portuguese VAT number or NIF verified against 9946

—Support for the document the recipient actually requires, including CIUS-PT

—Compliance with its own Peppol Authority's rules and the applicable eSPap requirements

—Separate FE-AP onboarding where a direct connection to the government gateway is used

Where the provider additionally performs conversion or fiscal compliance functions, it needs the Portuguese fiscal data and processes to be right — although the legal duty towards the AT remains the taxpayer's. Before a commercial launch it is worth obtaining written confirmation from eSPap that no additional non-public operational requirements apply to a foreign Access Point.

Penalties and VAT deduction

The general tax offences regime (Regime Geral das Infrações Tributárias, RGIT) provides the numbers that matter here.

€150 – €3,750Failure to issue a mandatory invoice, or issuing it late

€75 – €2,000Breach of the duty to demand or retain an invoice

€150 – €3,750The general range for missing or late mandatory documents and communications to the tax administration

up to €10,000Possible for certain breaches of the duty to transmit invoice data under Decreto-Lei 198/2012, depending on the legal characterisation

For legal persons the minimum and maximum limits are generally doubled. The actual amount depends on the degree of fault, how long the breach lasted, the tax at stake, whether it was voluntarily corrected, and the applicable reduction procedures.

Breaching the B2G mandate

Article 299-B CCP sets no separate universal fixed penalty for sending a PDF instead of a CIUS-PT invoice. In practice the document is technically rejected, is not recognised as a proper invoice for processing, a correct structured document is requested, the payment workflow does not start, contractual sanctions may follow, and general tax penalties apply if fiscal invoicing requirements were breached at the same time. Since the payment period on a public contract runs from receipt of the invoice or an equivalent document, not receiving a valid structured invoice can postpone the start of the payment period.

VAT deduction

A structured e-invoice is not the only lawful basis for deducting VAT across the whole economy. The Portuguese VAT Code links the right to deduct to VAT shown on invoices issued in legal form and held in the taxpayer's name and possession — it does not require that document to be a structured e-invoice in all B2B transactions. A proper paper invoice, a PDF recognised by tax law, a structured e-invoice or another compliant electronic invoice can all serve.

The deduction is at risk where the invoice lacks mandatory content, relates to a fictitious transaction, shows VAT charged unlawfully, is not in the taxpayer's possession, or where defects were never corrected by a corrective document.

Archiving

Electronic invoices must be retained for a minimum of ten years, with integrity, authenticity and legibility ensured throughout. Portugal then adds a location rule that catches out providers hosting outside Europe.

Digital archiving is permitted in Portugal or another EU member state, provided access through terminals located in Portugal is guaranteed

Archiving outside the EU requires prior authorisation from the AT — not a notification, an authorisation

Retain the XML where the invoice was structured, together with the ATCUD, QR data and the audit trail of the series

Ten years is long enough that the archive will outlive the software that produced it. Retaining the structured document, not merely a rendering, is what makes it possible to satisfy an AT audit years after a system migration.

ViDA and 2030

The ViDA package was finally adopted by the Council on 11 March 2025. From 1 July 2030, invoices for the intra-EU cross-border B2B transactions in scope must be issued in structured electronic form, with the data transmitted to the tax authorities in near real time. Existing national digital reporting systems must be brought into line with the ViDA framework by 1 January 2035.

ViDA does not make Portuguese domestic B2B e-invoicing mandatory by itself. Domestic transactions would need a separate national decision. What ViDA does put on Portugal's plate is the 2035 alignment question for the systems it already runs — SAF-T (PT), e-Fatura and the invoice data transmission obligation.

How we help

Portugal is a market where scope has to be stated precisely. This is the delivery circuit, and what it does and does not include:

CIUS-PT on UBL 2.1 for Invoice, CreditNote and debit notes, with XSD and Schematron validation before sending

Addressing on 9946 with the NIF verified and the identifier form checked against the recipient's SMP entry

Delivery over Peppol, and the recipient-specific routing that Portuguese public buyers vary between

Handling of FE-AP status messages, so a rejection is visible rather than an unexplained silence in the payment cycle

PDF visualisation alongside the XML, for buyers who still want a readable copy

Archiving of the structured document in a form that satisfies the ten-year rule and the EU location condition

A clear boundary with the fiscal circuit — certified software, series registration, ATCUD, QR and AT transmission are a separate workstream, and we will say so rather than imply otherwise

Connection by API, SFTP and CSV, with ERP and IDoc source data

Frequently asked questions

Can small companies still send PDF invoices in Portugal?

For tax purposes, yes — until 31 December 2026, under the transitional rule extended again by the 2026 State Budget. But this is the point most commentary gets wrong: the concession does not apply to public contracts. Structured CIUS-PT has been required from all main supplier categories in B2G since 1 January 2026, when the relief for micro, small and medium enterprises and for public bodies acting as suppliers expired.

What happens on 1 January 2027?

A plain PDF loses its automatic recognition as an electronic invoice for tax purposes, unless the legislature extends the transitional rule once more — which it has repeatedly done. From that point authenticity of origin and integrity of content must be ensured by a qualified electronic signature, a qualified electronic seal, or EDI under the European Model EDI Agreement. A qualified signature is one option among three, not the only route.

Does Peppol handle my Portuguese tax reporting?

No, and this is the most expensive assumption available in this market. Portugal runs two independent circuits: B2G delivery of a structured CIUS-PT invoice, governed by eSPap, and fiscal compliance — certified software, registered series, ATCUD, QR codes and transmission of invoice data — governed by the AT. Tax reporting is not performed automatically by the Peppol exchange and must be organised separately. The legal obligation towards the AT stays with the taxpayer.

Is Portugal a clearance country?

No. The supplier issues the invoice without prior authorisation, the AT assigns no clearance number after checking content, and the document does not pass through the tax authority before reaching the buyer. What exists is post-issuance centralised reporting plus fiscal controls on the document — pre-registered series, ATCUD and QR code. Those are controls, not clearance.

How and when is invoice data sent to the AT?

By the 5th day of the month following the month of issue, through one of three permitted routes: real-time transmission via the API, upload of the structured SAF-T (PT) billing file, or manual entry in the Portal das Finanças. Because the monthly route is available, Portugal does not have mandatory real-time reporting in the strict sense — the API is one channel, not an obligation.

When does SAF-T Accounting become mandatory?

It was deferred again by the 2026 State Budget: the first mandatory annual SAF-T Accounting file covers FY 2027 transactions and is filed in 2028. Do not confuse it with SAF-T Billing, which is already a monthly obligation covering invoices issued and is due by the 5th of the following month.

Which format should I build for B2G?

UBL 2.1 CIUS-PT — Invoice for invoices and debit notes, CreditNote for credit notes — with XSD and Schematron validation of CIUS-PT plus the additional FE-AP business rules. The European Commission country profile also lists UN/CEFACT CII CIUS-PT, but the direct FE-AP interface documentation is built around UBL 2.1, so confirm CII support with the specific recipient before relying on it.

Can a foreign Access Point serve Portuguese clients?

Yes. No separate national licence comparable to the Slovak digitálny poštár or the French plateforme agréée was identified, and no requirement for a Portuguese entity, office, servers, representative, mailbox or bank account. What is needed is valid Peppol certification, the applicable BIS profiles and AS4, correct participant registration verified against 9946, support for CIUS-PT, and compliance with your own Peppol Authority's rules and the applicable eSPap requirements. Direct FE-AP integration is a separate onboarding process with its own testing.

What are the penalties?

Under the RGIT: €150 to €3,750 for failing to issue a mandatory invoice or issuing it late; €75 to €2,000 for breaching the duty to demand or retain an invoice; €150 to €3,750 as the general range for missing or late mandatory documents and communications; and up to €10,000 for certain breaches of the invoice data transmission duty under Decreto-Lei 198/2012. For legal persons the limits are generally doubled. Article 299-B CCP sets no separate fixed penalty for sending a PDF instead of CIUS-PT — there the consequence is rejection, a delayed payment period and possible contractual sanctions.

Where may I archive Portuguese invoices?

For at least ten years, with integrity, authenticity and legibility ensured. Digital archiving is allowed in Portugal or another EU member state provided access through terminals located in Portugal is guaranteed. Archiving outside the EU requires prior authorisation from the AT — an authorisation, not a notification, which is a real constraint if your platform hosts elsewhere. Retain the XML together with the ATCUD, QR data and the series audit trail.

Summary

Portugal has a strict fiscal regime and a narrow invoicing mandate, and the two are routinely mixed up. Structured CIUS-PT is compulsory on public contracts for all main supplier categories since January 2026. Domestic B2B and B2C have no structured mandate — but every business with Portuguese VAT obligations lives with certified software, registered document series, ATCUD, QR codes and monthly transmission of invoice data.

The deadlines keep moving. The PDF concession now runs to 31 December 2026, and SAF-T Accounting has been pushed to FY 2027 for filing in 2028. Both were deferred by the 2026 State Budget, and both have been deferred before.

If you take one thing from this page: Peppol solves delivery to public buyers and nothing else. The AT circuit — series, ATCUD, QR, SAF-T — is separate work with a separate regulator, and the legal duty for it never leaves the taxpayer.

Resources

eSPap — FE-AP for suppliers The government gateway from the supplier's side: how to connect, the channels and the onboarding process eSPap — SPFin and the e-invoicing standards Where the CIUS-PT implementation guide and the semantic data model guide are published Portal das Finanças — invoicing The AT's guidance on certified software, document series, ATCUD, QR codes and transmitting invoice data e-Fatura The tax administration's invoice data portal — reporting and data control, not a delivery channel European Commission — eInvoicing in Portugal The country profile: CIUS-PT, the listed syntaxes, eSPap's role and the B2G implementation Peppol BIS Billing 3.0 The UBL-based profile underneath CIUS-PT delivery over the Peppol network Peppol Electronic Address Scheme code list Where 9946 for the Portuguese VAT number sits, alongside every other scheme European Commission — VAT in the Digital Age (ViDA) The 2030 requirements and the 2035 alignment question for Portugal's existing reporting systems Peppol Directory Check the participant identifier and published document types before sending to a Portuguese recipient

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