Introduction

Portugal has introduced strict fiscal regulations to ensure transparency, prevent fraud, and standardize invoicing processes. These rules apply to all companies issuing invoices, whether they are based in Portugal or abroad.

To comply with Portuguese law, invoices, receipts and other fiscally relevant documents must be generated using certified invoicing software and include specific mandatory elements defined by the Portuguese Tax Authority (AT).

In practice, this means your invoicing system must be able to:

• Digitally sign and chain invoices, receipts, and other fiscal documents,
• Register and communicate document series with the AT and generate the corresponding ATCUD,
• Produce a QR code on every fiscally relevant document,
• Report invoicing data to the AT, either in real time via Web Services or through monthly SAF-T (PT) XML exports, and
• From 2027 onward, secure PDF invoices with a qualified electronic signature (QES).

This guide walks you through how to meet these requirements by integrating with the SIGN PT API. It covers the concepts you need to understand (series, signing and chaining, ATCUD, QR codes, SAF-T), the endpoints involved, and the end-to-end flow for issuing, reporting, and archiving fiscally compliant documents from your ERP, POS, or invoicing system.

SIGN PT is a platform‑independent and software‑only solution. SIGN PT is a RESTful API that enables ERP, POS and invoicing systems to create, sign and report fiscally compliant documents in Portugal, and it operates with a stable internet connection.

FAQ

FAQs and additional technical resources for SIGN PT can be accessed via support.fiskaly.com.