Portuguese invoicing rules are more formal than many newcomers expect. If you carry on a business or professional activity in Portugal, you generally have to issue an invoice for each supply of goods or services, even when the customer is a private individual and even when you are exempt from charging IVA. The practical questions are which document to issue, when to issue it, how to number it, whether you need certified software, and how the invoice data reaches the Autoridade Tributária (AT).

1. The short version

  • Regular business or professional activity requires an invoice for supplies of goods and services.
  • In the normal case, issue it by the 5th working day after the goods are made available or the service is performed.
  • If the customer pays in advance, issue the invoice on the date you receive the advance.
  • Use a fatura when invoicing and payment happen at different times, a fatura-recibo when they happen at the same time, and a recibo to record later payment of an existing invoice.
  • Invoice data for documents subject to Portuguese invoicing rules must generally be communicated to AT by the 5th day of the following month.
  • If you use invoicing software and fall within the legal certification rules, it must be software previously certified by AT.
  • Document series normally have to be communicated before use so AT can generate the validation code used in the ATCUD.
  • Invoices and other fiscally relevant documents produced by certified invoicing software carry a QR code.
  • Accounting and supporting records normally have to be retained for 10 years, unless a special longer rule applies.

2. Fatura, fatura-recibo and recibo: what is the difference?

The names describe different moments in the commercial transaction:

  • Fatura (invoice): use this when the taxable operation takes place but payment is not being recorded at the same moment.
  • Fatura-recibo (invoice-receipt): use this when the transaction and payment coincide.
  • Recibo (receipt): use this when an invoice already exists and you later receive the money. The receipt documents settlement of that invoice.

For many freelancers issuing documents through the Portal das Finanças, these choices appear directly in the invoice/receipt workflow. Do not issue a new invoice merely because an older invoice has now been paid; normally you record the payment with the corresponding receipt.

3. When must an invoice be issued?

As a general rule, Portuguese VAT rules require the invoice no later than the 5th working day after:

  • the date a service is performed; or
  • the date goods are placed at the customer’s disposal.

If you receive all or part of the price before the normal invoicing point, the invoice must be issued on the date of that advance payment. Special rules can apply to particular transactions, continuous supplies, intra-EU operations and other specific situations, so businesses with more complex cross-border flows should have their accountant configure the invoicing process rather than applying the simple domestic rule mechanically.

4. IVA-exempt does not mean invoice-exempt

A very common mistake is to think that a person using the small-business exemption in Article 53 of the IVA Code does not need invoices. The exemption concerns collection of IVA; it does not normally remove the invoicing obligation.

If your invoice is exempt from IVA, the invoice should use the legally appropriate exemption wording/reason rather than simply showing a zero tax rate without explanation. The exact code or wording depends on the exemption being used. For Article 53 businesses, invoicing through the Portal das Finanças or compliant software normally provides the appropriate exemption selection.

Since the 2025 amendment to Article 40 of the IVA Code, supplies made by persons covered by the Article 53 exemption are also expressly included in the situations in which a fatura simplificada may be used.

5. What is a fatura simplificada?

A fatura simplificada is a shorter-form invoice allowed in specific situations. Under the current Article 40 rules it can be used, among other cases, for:

  • sales of goods by retailers or itinerant sellers to non-business customers when the invoice does not exceed €1,000;
  • other supplies of goods and services when the invoice does not exceed €100; and
  • supplies made by taxpayers covered by the Article 53 IVA exemption.

It still has mandatory information requirements. “Simplified” does not mean informal or unnumbered.

6. What information should an invoice contain?

The exact mandatory fields depend on the document and transaction, but a normal Portuguese invoice commonly includes:

  • supplier name/business name and NIF;
  • customer name/business name and NIF where required;
  • invoice date;
  • sequential document number and series;
  • description and quantity of the goods or services;
  • net amounts;
  • applicable IVA rate(s) and IVA amount, or the correct legal exemption reason;
  • total amount;
  • where applicable, ATCUD and QR code;
  • other mandatory wording relevant to the transaction, such as reverse-charge or self-billing references where applicable.

For a private consumer, the customer’s NIF is not universally mandatory if the customer does not request it. For business customers and situations where the identification is legally needed, obtain the correct fiscal details before issuing the document.

7. Invoice numbering and document series

Invoices must be numbered sequentially within a document series. Portuguese invoicing therefore is not a system where you freely edit invoice numbers after issuing documents.

Before using a new documentary series, the issuer normally communicates the series to AT. AT returns a validation code. The ATCUD combines that validation code with the sequential number of the document and uniquely identifies the document.

If you issue documents directly in the Portal das Finanças, this process is handled by the AT system. If you use commercial software, make sure the software’s series setup has been correctly communicated before you begin issuing production invoices.

8. What is the ATCUD?

ATCUD means código único do documento. It is designed to identify a fiscal document uniquely, independently of the issuer, document type and series. It is created from the AT validation code for the series plus the document’s own sequential number.

The ATCUD must appear on the relevant invoice or fiscally relevant document. When using the Portal das Finanças, AT generates it automatically. With third-party invoicing software, proper series configuration is therefore essential.

9. What is the QR code?

Invoices and other fiscally relevant documents generated by AT-certified invoicing software must include the prescribed QR code. It contains structured fiscal information that can be read electronically.

Do not confuse the QR code with ATCUD. They are separate requirements. AT’s FAQ also distinguishes processing methods: for example, documents printed by an authorised printer do not require a QR code, while invoices produced by certified invoicing software do.

10. Do you need certified invoicing software?

Not every tiny freelancer has to buy commercial accounting software. The important distinction is between the legal obligation to invoice and the circumstances requiring use of an AT-certified invoicing program.

Under Decree-Law 28/2019 and AT guidance, certified invoicing software is required where one of the relevant triggers applies, including where the taxpayer:

  • had prior-year turnover above €50,000 (with annualisation rules relevant to a first, shorter year);
  • uses a computer invoicing program; or
  • is required to keep organised accounting or has opted for organised accounting.

AT also provides its own invoicing facilities through the Portal das Finanças, and the ATGO app provides tools for issuing and consulting invoices, invoice-receipts and receipts. For a straightforward solo activity, the AT tools can therefore be a practical alternative to buying commercial software.

Important: do not assume that a random invoice template in Word, Excel, Google Docs or an uncertified online invoice generator is compliant merely because it produces a professional-looking PDF. Once your chosen method is a computer invoicing program and the certification rules apply, use a program on AT’s certified-software list or the official AT facilities.

11. How to check whether software is certified

  1. Open AT’s official Certificação de Software de Faturação page.
  2. Use the linked Lista dos programas certificados.
  3. Check the program/product and the relevant version rather than relying only on a software vendor’s marketing page.
  4. Confirm that the product can handle your actual workflow: domestic IVA, exemptions, cross-border invoices, credit notes, series/ATCUD, QR codes and e-Fatura communication as relevant.

Certification answers the fiscal-software compliance question; it does not tell you whether a product is pleasant to use or suitable for your business. Compare usability, accountant access, support, pricing and integrations separately.

12. Do invoices have to be communicated to AT?

Yes, persons subject to Portuguese invoicing rules for operations subject to IVA generally have to communicate the required document data to AT. For documents issued from 2023 onward, the legal communication deadline is generally the 5th day of the following month.

Depending on your invoicing setup, communication can happen:

  • automatically or in real time through a webservice;
  • through the Portal das Finanças;
  • through submission of the structured multidocument/SAF-T-based file supported by AT; or
  • automatically as part of using AT’s own issuing facilities.

Do not confuse the communication deadline with the deadline to issue the invoice. A service supplied on 2 June might need its invoice within the 5-working-day issuance rule, while the invoice data then has a separate communication deadline in the following month.

13. SAF-T (PT): what it is and what it is not

SAF-T (PT) is Portugal’s standard audit file format used for structured accounting/invoicing data. Businesses often encounter it because invoicing and accounting systems can export data in the prescribed format and because it forms part of several AT reporting workflows.

For a small operator, the practical point is usually not to build a SAF-T file manually. It is to make sure the invoicing/accounting system produces compliant data and that the person responsible for submissions understands which file or webservice is being used.

14. Can you email a PDF invoice?

Yes, electronic delivery is common, but a PDF emailed to a client is only the presentation/delivery layer. The underlying invoice still has to be created in a legally acceptable way, with the correct numbering, fields and fiscal processing. Sending a Word-generated PDF does not transform an otherwise non-compliant document into a compliant Portuguese invoice.

Electronic invoicing in particular contexts, including public procurement, can have additional technical rules beyond merely emailing a PDF. If you invoice Portuguese public bodies, check the dedicated public-sector e-invoicing requirements rather than assuming an ordinary PDF is sufficient.

15. Correcting mistakes: do not overwrite issued invoices

Once a fiscal document has been issued, do not quietly edit the original file or reuse its number. Corrections normally require the appropriate rectifying document, such as a nota de crédito (credit note), and in some circumstances a new corrected invoice.

This is especially important with certified software because fiscal documents, sequences and signatures are designed to preserve an audit trail. If an invoice went to the wrong customer, used the wrong amount or needs cancellation, use the software’s compliant correction workflow or ask your accountant which rectifying document is required.

16. What if your invoicing software stops working?

AT guidance provides for contingency handling when a taxpayer who is required to use certified invoicing software cannot access it because of genuine inoperability, such as equipment failure or power loss. The contingency route can involve authorised pre-printed documents that are subsequently recovered into the invoicing system.

This is not permission to keep a parallel homemade invoice book for convenience. If continuity matters to your business, agree a documented outage procedure with your software provider/accountant before an outage happens.

17. How long should invoices and records be kept?

Decree-Law 28/2019 provides a general 10-year retention period for books, records and supporting documents, unless a special rule requires longer. If a tax right has a longer relevant period, records may need to be maintained through that period.

For computerised accounting or invoicing, the records must remain securely stored, accessible, readable and protected against alteration or destruction. A folder containing only PDF copies is not necessarily a substitute for preserving the required underlying fiscal/accounting records and exports.

18. Freelancer example

Maria is a freelance translator registered as a trabalhadora independente. She completes a €500 translation for a company on 6 April and is paid on 30 April.

  1. She issues the appropriate fatura within the applicable issuance deadline rather than waiting until payment day.
  2. When the company pays on 30 April, she issues/records the corresponding recibo.
  3. If she is exempt from IVA under Article 53, she selects the appropriate exemption rather than adding IVA.
  4. If she issues through the Portal das Finanças, the official system handles the document sequence and AT reporting workflow.
  5. If she uses commercial invoicing software, she checks that it is AT-certified where certification is required and that her series/ATCUD setup is valid.

19. Company example

A Portuguese Lda. with organised accounting sells consulting services. Because it has organised accounting, its invoicing workflow should use compliant certified software (or an applicable AT facility), with its documentary series correctly communicated. Its accountant may receive invoice/accounting data through the software and use SAF-T or other structured exports for tax/accounting obligations.

The company should not treat invoices as editable commercial documents. Corrections need a traceable fiscal-document workflow.

20. Foreign clients and foreign currency

Having a customer abroad does not remove the Portuguese invoicing obligation. What changes can be the IVA treatment: place-of-supply rules, B2B versus B2C treatment, reverse charge, VIES, OSS and export/import rules may determine whether Portuguese IVA is charged and which wording appears on the invoice.

Likewise, invoicing in a foreign currency does not remove Portuguese bookkeeping and tax-conversion requirements. If foreign clients are a significant part of your business, configure currencies and cross-border tax treatments in the invoicing system rather than manually improvising them invoice by invoice.

21. Practical setup checklist

  1. Open activity with Finanças before conducting regular independent activity.
  2. Confirm your IVA regime and the exemption wording/rates that apply.
  3. Choose your invoicing method: Portal das Finanças/ATGO or suitable commercial software.
  4. If using software, verify whether certification is required and check the product on AT’s official certified list.
  5. Create and communicate document series correctly before production use.
  6. Test that ATCUD and, where applicable, the QR code are generated.
  7. Enter correct supplier and customer fiscal data.
  8. Issue invoices within the legal deadline; do not wait until month-end merely for convenience.
  9. Confirm how the invoice data is communicated to AT by the 5th of the following month.
  10. Use receipts for later payments and proper rectifying documents for errors.
  11. Back up fiscal/accounting data and preserve it for the required retention period.
  12. If you have an accountant, give them access or exports in the format and frequency they request.

22. Common mistakes

  • “I do not charge IVA, so I do not need invoices.” Usually wrong.
  • Creating invoices in Word/Excel because they look professional. Appearance is not fiscal compliance.
  • Waiting until the client pays before issuing anything. The invoice deadline is tied to the transaction, with a separate receipt/payment step where appropriate.
  • Confusing the 5-working-day invoice deadline with the 5th-of-next-month communication deadline.
  • Starting a new invoice series without communicating it where required.
  • Editing or deleting an already-issued invoice instead of using a rectifying document.
  • Assuming all €0-IVA invoices use the same exemption wording.
  • Using uncertified software where certified software is required.
  • Keeping only customer-facing PDFs and losing the underlying accounting/fiscal records.

23. Official sources and useful tools

Last verified: 2 October 2026. Invoicing rules differ for some sectors, public-sector e-invoicing, self-billing, transport documents and cross-border transactions. For complex invoicing flows, have a contabilista certificado confirm the setup before issuing production documents.