Portuguese Invoice Requirements: NIF, ATCUD and QR Codes

A Portuguese invoice needs a dated, sequential number; supplier and required customer identification; a clear description and quantity; net values; applicable VAT rates and amounts, or the legal reason for non-application; and the supply or payment date when different. The issuing method also determines the validated-series, ATCUD, QR-code, and certified-software requirements.

What are the mandatory elements of a Portuguese invoice?

Article 36 of the Portuguese VAT Code is the starting point for a full invoice. It requires the document to be dated and numbered sequentially. It must identify the supplier and, where the customer is a taxable person, the customer, including the relevant names, addresses, and tax identification numbers. The remaining fields explain what was supplied, how it was valued, and how VAT was treated.

The general deadline is no later than the fifth working day after VAT becomes chargeable. If payment is received before the supply, or at the same time VAT becomes chargeable, Article 36 requires issue on the receipt date. Specific rules, including a deadline for certain intra-Community services, mean that the commercial event must be checked rather than applying one date mechanically.

When must the customer's NIF appear?

A customer's NIF is mandatory when the customer is a taxable person. For a consumer who is not acting as a taxable person, Article 36 makes the NIF mandatory when that consumer asks for it. The absence of a NIF does not, by itself, create a monetary limit for a full invoice and does not turn a payment receipt into a fiscal invoice.

Article 40 has separate rules for a simplified invoice where tax is due in Portugal. It permits one for goods sold by retailers or street vendors to non-taxable customers up to EUR 1,000, and for other supplies of goods or services up to EUR 100. It also covers supplies by taxable persons under the Article 53 exemption category. The simplified document still needs the supplier's identity and NIF, its own date and sequence, the description and quantity, price and tax information, and the customer's NIF when the customer is taxable or requests it.

The detailed guide to an invoice without a NIF in Portugal explains why the EUR 1,000 and EUR 100 thresholds belong to simplified invoices, not to every consumer invoice without a tax number.

What do FT, FR, FS, and NC mean?

The code identifies the fiscal document's role. It is not a design choice for the PDF. The transaction, payment timing, and need to correct an earlier document determine which type is appropriate.

The automated issuance flow covered here supports FT and FR only. It does not treat an FS as another label for an FT or generate an NC from a refund. A successful Stripe payment is already settled; it must not be placed into a second payment-confirmation flow merely because the configured fiscal document is an FT rather than an FR.

How do sequential numbering and invoice series work?

Decree-Law 28/2019 requires invoices and other fiscally relevant documents to be dated and numbered progressively and continuously inside each series, for at least one tax year. A business may use more than one series for genuine operational needs, but each series remains a controlled sequence. Deleting document 417 and renaming document 418 as 417 would destroy that record.

The series is also linked to the document type. Before a series is used, it is reported electronically to the Tax Authority. The report includes the series identifier, document type, starting sequential number, and intended start date. The Tax Authority then assigns the validation code that becomes part of ATCUD. An FT and an NC using the same visible series label are still different type-and-series combinations.

When is certified invoicing software mandatory in Portugal?

The obligation is not universal, but Article 4 of Decree-Law 28/2019 uses alternative triggers. As at 28 August 2026, a taxable person within its scope must use software previously certified by the Tax Authority if prior-year turnover exceeded EUR 50,000, if the person uses invoicing software, or if organised accounts are mandatory or were chosen voluntarily. Meeting any one trigger is enough.

Tax Authority applications remain an allowed issuing method under Article 4-A. For a taxable person who meets an Article 4 trigger, documents pre-printed by an authorised printer are only a fallback while certified software is inoperable. Neither rule makes an ordinary spreadsheet a certified invoicing program. Where software is used, its exact program and version should appear on the Tax Authority's current certification list.

Ordinance 363/2010 sets technical requirements for certification. The program must export SAF-T (PT), identify invoice and rectifying-document records through asymmetric cryptography, control access by user, and prevent fiscal data from being changed without evidence attached to the original information. Its document signature chains specified data to the previous document of the same type and series. This is a fiscal digital-signature mechanism, not a claim that the PDF carries a qualified electronic signature under eIDAS.

What is the exact certified-software wording?

Article 6 of Ordinance 363/2010 requires signed documents to print four characters selected from the signature and the certificate number. The prescribed Portuguese expression is Processado por programa certificado n.º.... It should not be translated on the fiscal document or replaced with a marketing claim such as “compliant software”. The number identifies the certified program; it is not the supplier's NIF or the series validation code.

How do ATCUD and the QR code fit on the invoice?

ATCUD combines the validation code assigned to the series with the document's number inside that series, separated by a hyphen. Ordinance 195/2020 sets a minimum of eight characters for the series validation code and prescribes the printed format ATCUD:ValidationCode-SequentialNumber. ATCUD must remain legible and appears on every page of a multi-page document.

The QR code is different. It encodes tax fields under the Tax Authority's technical specification and is mandatory on invoices and other relevant documents issued by certified invoicing software. It may appear on the first or last page and must remain legible. A QR code copied from another document, or a visually plausible ATCUD typed into a template, does not reproduce the controlled series and signed record behind the invoice.

The separate guide to ATCUD and QR codes on Portuguese invoices covers series registration, effective dates, and validation in detail.

What does an annotated Portuguese invoice look like?

Consider a fictional final document for a paid software subscription. The labels below show where each control comes from; they do not create a real invoice or a valid ATCUD.

Why do invoice templates and generic tools fail?

A template can display the mandatory fields, but it does not by itself register a series, preserve progressive numbering, create the fiscal signature chain, generate a QR from the final record, or prove that the program version is certified. Editing the PDF after issue also separates its appearance from the data that was signed and recorded.

That does not mean every small issuer is forced into the same commercial application. It means the lawful issuing method and the certified- software triggers must be checked before choosing the tool. The guide on whether a Stripe invoice is valid in Portugal applies the same test to payment documents.

What should be checked before automating Portuguese invoices?

1. Identify whether the output is FT or FR and configure the intended series before the first issue.
2. Confirm that the issuing method is lawful and, where software is used, verify its exact version on the Tax Authority certification list.
3. Collect the supplier, customer, line, date, and tax data required for the transaction. Do not derive a VAT rate from a NIF, postal address, country, or other heuristic.
4. Pass through the amounts and tax treatment configured in Stripe to the accounting provider. If required tax mapping or exemption data is missing, stop for review instead of inventing it.
5. Reconcile the successful payment with the final fiscal document, including its type, number, ATCUD, total, and provider identifier.

For the complete workflow, see how to automate Stripe invoicing in Portugal. The guide to the Portuguese e-invoicing mandate separates structured electronic invoicing from ordinary PDF delivery. These checks keep payment evidence, invoice data, and the certified record connected without treating one as a substitute for another.