Source: https://rivet.global/blog/portugal-invoicing-foreign-clients-atcud-saf-t
Published: 2026-09-11 · Updated: 2026-09-11 · By William Sunjo M.

# Invoicing foreign clients from Portugal: certified software, ATCUD and SAF-T

The rules a Portuguese company follows when it invoices clients abroad: certified invoicing software, ATCUD codes, QR codes, SAF-T reporting and VAT wording.

## Key takeaways

- Portuguese companies must issue invoices from software certified by the tax authority (AT), whether the client is local or foreign.
- Every invoice carries an ATCUD, a unique document code built from a series code registered with AT, and a QR code.
- Invoice data is reported to AT through the SAF-T (PT) file, generally by the 5th of the following month.
- Services to foreign businesses are usually invoiced without IVA, with the legal reason stated.

A Porto software consultancy sends its first invoice to a client in Boston. It drafts the invoice in a spreadsheet, in dollars, and emails a PDF. Under Portuguese rules, that invoice does not exist. Invoices in Portugal come from certified software, and that holds whether the client is in Braga or Boston.

## Certified software

Portugal's tax authority (Autoridade Tributária, AT) certifies invoicing programmes. Every invoice a Portuguese company issues must come from one, with a few narrow exceptions for very small businesses using the AT portal's own invoicing tool. Certified software signs each document so it cannot be altered after issue.

## ATCUD and QR code

Since 2023 every invoice carries two extra elements:

- ATCUD, a unique document code. You register each invoice series with AT, receive a validation code for it, and the software combines that with the document number.
- A QR code holding the invoice's main data, so AT and clients can check it.

Both apply to invoices to foreign clients too.

## SAF-T reporting

Invoice data goes to AT through the SAF-T (PT) file. Most companies submit it monthly, generally by the 5th of the following month, either through the AT portal or directly from the software. A missing or late submission carries fines, and a mismatch between SAF-T and your IVA return invites questions.

## VAT on foreign invoices

For most services:

- To EU businesses: no Portuguese IVA. Show the client's VAT number, validate it in VIES and state that the reverse charge (autoliquidação) applies.
- To businesses outside the EU: no Portuguese IVA, with the legal reason stated on the invoice.

Goods exports have their own rules and need customs evidence.

## Invoicing in dollars

You can invoice in dollars. If VAT appears, show it in euros too, and record each invoice in your books in euros at a documented rate. Your certified software should handle a second currency; check before the first dollar invoice.

## Getting paid

A Boston client paying a Portuguese IBAN must send an international wire. It may arrive short after intermediary fees, and a euro account converts it at the bank's rate on arrival. US account details let the client pay by ACH, and the full amount lands in dollars for you to convert when it suits you, or keep for dollar costs.

## Paying into Portugal: the local rail

| What | Detail |
|---|---|
| Local rail | SEPA Instant Credit Transfer (MB WAY for mobile transfers) |
| Run by | European Payments Council scheme, run by each bank |
| Settlement | Under ten seconds, 24/7 |
| Published fee | By the EU Instant Payments Regulation, no more than the bank charges for a standard SEPA transfer |

Source: [European Payments Council: SEPA Instant Credit Transfer](https://www.europeanpaymentscouncil.eu/what-we-do/sepa-instant-credit-transfer). Checked when this guide was last updated; the scheme's own page has the current figures.

## Where Rivet fits

Rivet does not issue certified invoices or SAF-T files; keep your certified software for that. A Rivet business account handles the collection: US account details in the company's own name on every plan, euro and sterling details from the Growth plan, payments matched to invoices, and balances held or converted at a rate shown before you confirm. Rivet is not a bank; regulated partner institutions hold the funds.

See also [how to invoice international clients](/blog/how-to-invoice-international-clients).

## Questions

### Do invoices to foreign clients need an ATCUD?

Yes. The ATCUD and QR code requirements apply to invoices issued by Portuguese companies regardless of where the client is.

### Can I invoice a foreign client in US dollars from Portugal?

Yes. The invoice can be in another currency, but VAT amounts, where shown, must also appear in euros, and accounting records are kept in euros.

### What is SAF-T (PT)?

A standard file that exports invoice data from your certified software to the tax authority. Most companies submit it monthly through the AT portal or have their software do so.

### What IVA wording goes on an invoice to an EU business?

The invoice shows no Portuguese IVA, includes the client's VAT number and states that the reverse charge applies (autoliquidação), with the legal reference.