Portugal requires structured e-invoices for public contracts: large companies have issued them to public bodies since 1 January 2021, and small, medium and micro enterprises must do so from 1 January 2027, according to eSPap, the public shared-services agency. Invoices follow CIUS-PT, the Portuguese version of EN 16931. Between businesses there is no structured e-invoicing obligation; paper and PDF invoices with the required QR code remain possible.
This page summarises eSPap's official FAQ and the European Commission's country sheet, checked on 5 November 2026. It is not tax advice; your contabilista certificado can tell you how the rules apply to you.
What applies to whom?
| Obligation | Who | From | Channel | Status | Source |
|---|---|---|---|---|---|
| Receive and process e-invoices | The State (direct administration and sovereign bodies) and public institutes | 18 April 2019 | FE-AP or the body's own route | in force | eSPap |
| Receive and process e-invoices | Other public contracting parties: autonomous regions, local authorities, Banco de Portugal and others | 18 April 2020 | as above | in force | eSPap |
| Issue e-invoices under public contracts | Large companies | 1 January 2021 | FE-AP, third-party portals or the body's route | in force | eSPap |
| Issue e-invoices under public contracts | Small, medium and micro enterprises, and public bodies acting as suppliers | 1 January 2027 | as above | enacted | eSPap |
| Send invoice data to the tax authority | All resident taxpayers | January 2013, monthly | SAF-T (PT) file or certified software | in force | European Commission |
Large companies, in this rule, follow Commission Recommendation 2003/361/EC: more than 250 employees, or annual turnover over EUR 50 million, or a balance sheet total over EUR 43 million. Invoices under simplified direct awards and secret contracts are exempt (eSPap, in Portuguese).
Which date is right for SMEs?
eSPap's FAQ, citing article 9 of Decree-Law 111-B/2017 as amended by the 2026 State Budget Law (Law 73-A/2025), gives 1 January 2027 for small, medium and micro enterprises. The European Commission's sheet is internally inconsistent, naming both 2025 and 2027; eSPap explains that the deadline was extended. Rely on the eSPap date and check it again before the deadline, as later budget laws can change it.
How are invoices sent to public bodies?
There is no single mandatory portal. eSPap's FE-AP solution receives CIUS-PT invoices from suppliers by web service or AS2 after registration, validates them and passes them to the public bodies that use it; suppliers follow their documents in the B2AP portal. Suppliers that issue fewer than 250 documents a year can upload invoices by hand in the FE-AP Microportal. Other public bodies use third-party portals, which may charge the supplier, so check the route each customer uses (eSPap, in Portuguese).
What about invoices between businesses?
The Commission's sheet records no B2B or B2C e-invoicing obligation (European Commission). Businesses may use paper or PDF invoices, which carry a QR code and the ATCUD, a unique document code, produced by certified invoicing software. Under article 95(3) of the 2026 State Budget Law (Law 73-A/2025), PDF invoices are accepted as electronic invoices for all tax purposes until 31 December 2026 (eSPap, question 2.14, in Portuguese). The Commission's sheet still gives 1 January 2026 for a qualified electronic signature on PDF invoices. For the rule from 2027, ask the Autoridade Tributária or your contabilista.
Which formats are used?
| Format | Used for | Notes |
|---|---|---|
| CIUS-PT in UBL 2.1 | invoices to public bodies | the Portuguese specification of EN 16931 |
| CIUS-PT in CII | invoices to public bodies | named by the Commission as the second syntax |
| SAF-T (PT) | monthly invoice data and accounting files for the tax authority | a reporting file, not an invoice |
| ATCUD and QR code | printed and PDF invoices | produced by certified software |
What can Klarbon do with Portuguese invoices?
| You want to | Tool | Limit |
|---|---|---|
| Read a CIUS-PT invoice | open an e-invoice, free | in beta |
| Check a UBL or CII file against EN 16931 | check an e-invoice | not the CIUS-PT rules |
Klarbon does not send invoices to FE-AP or other portals, sign PDFs, issue ATCUD codes or produce SAF-T (PT) files.
Related
E-invoicing deadlines by country
| Country | Scope | Obligation | From | Who | Source |
|---|---|---|---|---|---|
| Portugal | B2G | Receive | In law | Contracting authorities and entities covered by Directive 2014/55/EU for in-scope public procurement invoices conforming to EN 16931. | Official source |
Frequently asked questions
Is e-invoicing mandatory in Portugal?
For public contracts, yes. Large companies have had to issue structured e-invoices to public bodies since 1 January 2021, and small, medium and micro enterprises must do so from 1 January 2027, according to eSPap. There is no structured e-invoicing obligation between businesses.
When do Portuguese SMEs have to send e-invoices to public bodies?
From 1 January 2027, under article 9(4) of Decree-Law 111-B/2017 as amended by the 2026 State Budget Law, according to eSPap. Older sources give 2025 or earlier dates, which were postponed.
Which format do Portuguese public bodies accept?
CIUS-PT, the Portuguese specification of the European standard EN 16931, for example in UBL 2.1. eSPap validates documents sent through its FE-AP solution against CIUS-PT.
Do PDF invoices in Portugal need a qualified signature?
Not until the end of 2026. eSPap, citing article 95(3) of the 2026 State Budget Law, says PDF invoices are accepted as electronic invoices for all tax purposes until 31 December 2026. The Commission's sheet gives 1 January 2026 for a qualified signature, a date the budget law has overtaken; ask the Autoridade Tributária what applies from 2027.
Can Klarbon open a CIUS-PT invoice?
Yes, in beta. Klarbon opens CIUS-PT invoices so you can read them. It does not send invoices to public bodies, sign them or produce SAF-T files.