E-invoicing in Portugal: A Complete Guide for Businesses

What is Portugal e-invoicing?

Portugal operates one of Europe's most mature invoice control frameworks, built around two complementary obligations: ATCUD (Código Único de Documento — Unique Document Code) and SAF-T PT (Standard Audit File for Tax). Together, these create a near-real-time reporting trail that the AT (Autoridade Tributária e Aduaneira — Tax and Customs Authority) uses to audit businesses.

Unlike Italy's clearance model, Portugal does not require invoices to be pre-approved before delivery. Instead, businesses must embed an ATCUD code in every invoice (generated using a series validation code obtained from AT), and communicate invoice data to AT monthly — by the 5th of the following month (Decreto-Lei n.º 198/2012), per invoice or via the SAF-T PT billing file. The framework is complemented by mandatory use of AT-certified invoicing software — only software certified by AT may legally issue invoices in Portugal.

The legal basis spans multiple decrees, including Portaria n.º 195/2020 (ATCUD technical specification) and Decreto-Lei n.º 28/2019 (invoicing obligations).

The SAFT-PT + ATCUD format

Portugal's invoice data obligations consist of two components:

ATCUD (per invoice):

• A unique code in the format ATCUD:VALIDATION_CODE-SEQUENTIAL_NUMBER
• The validation code is obtained from AT per invoice series via the AT web service (SeriesRegistration)
• Must appear visually on the invoice and in the SAF-T PT export

SAF-T PT (monthly reporting):

• XML file conforming to the Portuguese SAF-T schema (currently version 1.04)
• Contains all invoices, credit notes, and payment records for the reporting period
• Submitted to AT via the AT portal or directly via API
• Structure: Header, MasterFiles (customers, products, tax table), SourceDocuments (invoices, payments)

Key invoice fields:

• InvoiceNo: sequential number within a series, in format SERIES TYPE/NUMBER (e.g. FT 2025/145)
• InvoiceType: FT (tax invoice), FS (simplified invoice for <EUR 1,000), NC (credit note), ND (debit note)
• TaxRegistrationNumber: Portuguese NIF (9 digits) for supplier and buyer
• ATCUD: required on all invoices from 2023

Who does it apply to?

There is no B2B e-invoicing clearance mandate analogous to Italy — Portugal's model is reporting-based.

Timeline / key dates

• Jan 2019: SAF-T PT mandatory for all VAT-registered businesses
• Jan 2020: Hash-signing of invoices mandatory (QR code on invoices from 2020)
• Jan 2023: ATCUD mandatory on all invoices
• Ongoing: AT regularly updates the SAF-T PT schema and ATCUD technical specification

How Clearvo handles Portugal e-invoicing

Clearvo issues AT-certified invoices and handles ATCUD series registration with AT, ATCUD and QR code generation per invoice, per-invoice communication of invoice data to AT, and the monthly SAF-T PT billing file.

Key points:

• Clearvo registers your invoice, credit-note and debit-note series with AT and stores the validation codes — or uses the series and ATCUD codes you already hold. You configure this once via POST /v1/pt/credentials
• Each invoice receives a sequentially generated ATCUD code and QR code, and its data is communicated to AT automatically ahead of the 5th-of-the-following-month deadline
• For any month, Clearvo generates the complete SAF-T PT XML file covering all invoices, credit notes and debit notes in the period
• Clearvo is AT-certified invoicing software; the documents it issues satisfy the InvoiceNo formatting, InvoiceType, and hash-signing requirements

What you send: standard invoice fields with country: "PT" and the Portuguese NIF in supplier.taxId / buyer.taxId. The entity's AT details (sub-user + password, or existing series + ATCUD codes) are configured once via POST /v1/pt/credentials.

What you get back: the invoice with embedded ATCUD, QR code data, and hash signature.

{
  "documentType": "invoice",
  "country": "PT",
  "issueDate": "2025-06-01",
  "dueDate": "2025-07-01",
  "currency": "EUR",
  "supplier": {
    "name": "Acme Software Lda",
    "taxId": "PT123456789",
    "address": {
      "street": "Avenida da Liberdade 200",
      "city": "Lisboa",
      "postalCode": "1250-147",
      "country": "PT"
    }
  },
  "buyer": {
    "name": "TechPrime Soluções SA",
    "taxId": "PT987654321",
    "address": {
      "street": "Rua do Comércio 44",
      "city": "Porto",
      "postalCode": "4000-150",
      "country": "PT"
    }
  },
  "lines": [
    {
      "description": "Subscrição de software — junho 2025",
      "quantity": 1,
      "unitPrice": 1800.00,
      "taxRate": 23
    }
  ]
}

Getting started

ATCUD series registration, per-invoice communication to AT, and SAF-T PT generation are documented in the Portugal guide. A sandbox environment is available for end-to-end integration testing.

Related country guides

• Spain — VeriFactu hash-chain + Peppol B2B mandate
• France — Factur-X PDP model, mandate from September 2026
• Italy — FatturaPA SDI clearance, mandatory since 2019

Frequently asked questions

What is ATCUD and is it mandatory? ATCUD (Código Único de Documento — Unique Document Code) is a mandatory identifier that must appear on every invoice issued by a Portuguese-registered business from 1 January 2023. The code follows the format ATCUD:VALIDATION_CODE-SEQUENTIAL_NUMBER, where the validation code is obtained from the AT (Autoridade Tributária) per invoice series. There is no SME exemption — the obligation applies to all VAT-registered businesses.

When must SAF-T PT be submitted? Invoice data must be communicated to the AT monthly, by the 5th of the month following the reporting period (Decreto-Lei n.º 198/2012) — either per invoice through the AT webservice or by submitting the SAF-T PT (Standard Audit File for Tax — Portugal) billing file. The SAF-T PT file covers all invoices, credit notes and debit notes for the calendar month, and AT may also request it at any time. Clearvo communicates each invoice to AT automatically and generates the monthly SAF-T PT file for you.

Does Portugal's framework apply to foreign businesses with a Portuguese VAT number? Yes. If your business holds a Portuguese VAT registration, the full obligations apply regardless of where your company is incorporated: ATCUD on every invoice, use of AT-certified invoicing software, and monthly SAF-T PT submission. Foreign businesses with a PT VAT number should ensure their invoicing software is AT-certified before issuing invoices.

What is AT-certified software and why does it matter? Portuguese law (Decreto-Lei n.º 28/2019) requires that invoices be issued by software certified by the AT. Certification confirms that the software meets integrity, sequential numbering, and reporting requirements. Invoices produced by uncertified software are not legally valid for VAT deduction purposes. Clearvo issues AT-certified invoices.

How does Clearvo handle ATCUD series registration? You register your AT details once via POST /v1/pt/credentials. Give Clearvo an AT webservice sub-user and password and it registers your invoice, credit-note and debit-note series with AT and stores the validation codes — or supply the series and ATCUD validation codes you already hold. Every document then receives a sequentially generated ATCUD code, and the sequence counter is managed per series by Clearvo, so you never need to manage them manually.