ERP and accounting software for Portugal: SAF-T, ATCUD, SNC

Portuguese compliance in one view

Running the books of a Portuguese business means issuing every invoice from AT-certified software with an ATCUD and QR code, reporting invoice data to the Autoridade Tributária e Aduaneira by the 5th of the next month, filing VAT returns monthly or quarterly, and keeping ten years of records. It matters because the invoicing system itself is regulated, not just the returns.

Portugal has no structured business-to-business e-invoicing mandate as of September 2026, yet it is one of the most controlled invoicing environments in Europe. Certification of invoicing software has applied since Portaria 363/2010, the unique document code and QR code are set by Portaria 195/2020, and the Standard Audit File for Tax, SAF-T (PT), is the format in which invoice data leaves the business. The annual accounting SAF-T file is the next step.

This page explains those rules and the accounting and audit framework under the SNC, and sets out what Skyline Nexus ERP covers for a Portuguese company today, what is being rolled out, and how the two fit around the certification rule.

• Tax authority: AT, filing through the Portal das Finanças
• Currency: euro; standard VAT rate 23% on the mainland
• Invoicing: AT-certified software, ATCUD and QR code
• Invoice reporting: by the 5th of the following month
• Accounts: SNC; EU-adopted IFRS for listed groups
• Retention: ten years

VAT rates and returns

Article 18 of the VAT Code (CIVA) sets three mainland rates: 6% for goods and services in Annex I, 13% for those in Annex II and 23% for everything else. The European Commission lists the 13% rate as one of the EU's parking rates. The legislative assemblies of the Azores and Madeira may set lower rates for supplies made in those regions, which is why the same product can carry a different rate on an island invoice.

Periodic VAT returns follow article 41 of the CIVA. A business with annual turnover of 650,000 euro or more files monthly; below that, it files quarterly. In both regimes the return is due by the 20th day of the second month after the period. Because the AT already holds invoice data reported by the 5th of each month, differences between what customers and suppliers reported and what the return declares are easy for the AT to spot.

The practical requirement for any ledger is a tax rate on every invoice line, separate codes for mainland and regional rates, and exemption reasons that map to the codes the AT publishes for invoice reporting.

• 23% standard, 13% intermediate, 6% reduced on the mainland
• Azores and Madeira: lower regional rates under article 18(3) CIVA
• Monthly returns from 650,000 euro turnover; quarterly below
• Due by the 20th of the second month after the period

Certified invoicing software: the rule that decides your system

Decreto-Lei 28/2019 lists three ways to produce invoices: invoicing programs, including the free invoicing applications the AT itself provides; other electronic means such as cash registers, which may only issue the simplified invoices of article 40 of the CIVA; and forms pre-printed by an authorised printer. Article 4 then requires a Portuguese business to use AT-certified programs exclusively when its turnover exceeded 50,000 euro in the previous calendar year, when it uses invoicing software, or when it keeps organised accounts.

Certification is granted per program and version under the requirements of Portaria 363/2010, and the AT keeps a public list of certified programs, versions and producers. A certified program signs each document with a private key, chaining in the signature of the previous document of the same series, prints the ATCUD and QR code, and produces the SAF-T (PT) file. If a certified program fails, invoices must be issued on pre-printed forms and later recovered into the program.

For anyone choosing an ERP for Portugal, this is the first question to ask, before any feature list: is the invoicing module on the AT's certified list for the version you will run? If it is not, invoices must come from a certified program, and the ERP receives them.

ATCUD, QR code and monthly invoice reporting

Before a document series is used, the business communicates it to the AT, giving the series identifier, the document type, the first sequential number and the planned start date, and receives a validation code of at least eight characters. The unique document code is that validation code joined by a hyphen to the document's sequential number and printed as ATCUD:validation code-number. It must be legible on every invoice and fiscally relevant document, on every page, directly above the QR code where one is printed.

The QR code follows technical specifications published by the AT and must be generated correctly by the producer of a certified program. It lets the invoice be read without re-keying, and consumers can use the QR code or the ATCUD to register with the AT invoices that were issued without their tax number.

Invoice data then reaches the AT monthly. Under Decreto-Lei 198/2012 as amended, the elements of invoices must be communicated by the 5th day of the month after issue, by uploading the SAF-T (PT) invoicing file, through a web service, or directly on the portal. A month with no invoices must also be declared. Goods transport documents follow a stricter rule: they are communicated to the AT, with their unique document code, before transport starts, unless the business's turnover in the previous period was 100,000 euro or less.

E-invoicing: public sector, PDFs and signatures

Suppliers to public bodies must send structured electronic invoices that follow CIUS-PT, Portugal's implementation of the European standard EN 16931, in UBL or CII syntax. The obligation has been phased in by company size, and the deadlines for smaller suppliers have been extended more than once, so check the date that applies to your business. Invoices reach public entities through the national receiving platforms.

Between businesses, electronic invoices are allowed when the recipient accepts them, and there is no structured-format mandate as of September 2026. Article 12 of Decreto-Lei 28/2019 treats the authenticity of origin and integrity of content as guaranteed where the issuer applies a qualified electronic signature, a qualified electronic seal under the eIDAS Regulation, or exchanges invoices under an EDI agreement following the European model. A transitional tolerance for unsigned PDF invoices has been extended several times; confirm the current position with the AT before relying on plain PDFs.

Cross-border, the EU's VAT in the Digital Age package brings mandatory e-invoicing and digital reporting for intra-EU business supplies from 1 July 2030. For a Portuguese business the preparation is the same data discipline that ATCUD and SAF-T already demand.

SAF-T (PT): the invoicing file today, the accounting file next

SAF-T (PT) is Portugal's version of the OECD Standard Audit File for Tax, defined by Portaria 321-A/2007 as amended. Two variants matter. The invoicing variant carries sales documents, receipts, working documents and goods movement documents, and it is the usual vehicle for the monthly invoice communication. The accounting variant carries the chart of accounts, journals and journal transactions.

The accounting file is also becoming part of the annual Informação Empresarial Simplificada (IES), the single annual return of accounting, tax and statistical data. Decreto-Lei 48/2020 set the procedure: before submission, accounting programs obtain a key from the national mint (INCM) and encrypt descriptions and personal data in the file, and the AT may use the detailed data only within an inspection. As of September 2026, the European Commission's country profile indicates that the first mandatory accounting SAF-T files relate to the 2026 financial year and will be submitted in 2027. The start has been postponed before, so confirm the current date with the AT.

For system selection, this means the general ledger must hold clean account codes, dated and numbered journals and customer and supplier identifiers that can be exported to the SAF-T structure without manual rework.

SNC accounting, statutory audit, payroll and retention

Portuguese companies prepare accounts under the Sistema de Normalização Contabilística (SNC), maintained by the Comissão de Normalização Contabilística. The current SNC framework applies to periods beginning on or after 1 January 2016, with a simplified standard for micro-entities. Groups with securities listed on an EU regulated market use IFRS as adopted by the EU in their consolidated accounts under Regulation (EC) 1606/2002.

Statutory audit follows the Commercial Companies Code. Under article 262, a private limited company (sociedade por quotas) without a supervisory board must appoint a statutory auditor (revisor oficial de contas) once it exceeds two of three limits for two consecutive years: balance sheet total 1,500,000 euro, net sales and other income 3,000,000 euro, and an average of 50 employees.

Employers report monthly to the social security system and withhold personal income tax (IRS) on salaries for the AT, so the payroll journal needs separate liabilities for each. Records must be kept for ten years, and article 19 of Decreto-Lei 28/2019 requires electronic records to be stored with integrity controls and kept readable and accessible to the AT for the whole period.

Cities and regions: where the rules differ

Invoicing certification, ATCUD, SAF-T and the VAT return are national, so a business in Lisbon, Porto, Braga, Coimbra, Aveiro, Leiria, Setúbal or Faro works under one rulebook. The genuine regional difference is VAT in the two autonomous regions.

In Madeira, with its capital Funchal, and in the Azores, with its main business centre in Ponta Delgada, the regional legislative assemblies set VAT rates lower than the mainland's 23%, 13% and 6%, as article 18(3) of the VAT Code allows. A company that sells from Lisbon to a customer in Funchal must therefore work out where the supply is taxed and apply the correct rate set, and a group with branches on the mainland and the islands needs separate tax codes per region.

Beyond VAT rates, nothing in this page's obligations changes by city. The same certified software, the same monthly invoice communication and the same ten-year retention apply everywhere in the country.

• Mainland cities: one set of VAT rates and one invoicing regime
• Madeira (Funchal): regional VAT rates below the mainland's
• Azores (Ponta Delgada): regional VAT rates below the mainland's
• Everywhere: certified software, ATCUD, SAF-T and ten-year retention

How Skyline Nexus ERP handles Portuguese requirements

Skyline Nexus ERP is a cloud ERP with a double-entry general ledger under Fiscal Authority. When the auto-post switches are on, purchases, payments, expenses and depreciation post balanced journals in the background, with VAT computed per line. Each VAT rate is its own tax rate, so mainland, Madeira and Azores rates sit side by side and the right one is chosen on each line. The VAT Return screen prefills tax-exclusive bases and VAT for a date range, ready to be entered on the periodic return in the Portal das Finanças. Posted journals are corrected by reversal, fiscal periods can be closed and locked, and an Accounting Audit Trail records changes with old and new values, user and time.

Business locations carry their own stock and a branch-filtered trial balance, profit and loss and balance sheet, useful for a group with mainland and island branches. The interface and the Accounting module are available in Portuguese. For the ten-year retention period, the Audit Pack exports each year's chart of accounts, journals, general ledger, sales, purchases and VAT summary to one Excel workbook.

National invoicing connectors are being rolled out market by market, and for Portugal that programme covers ATCUD and AT QR code output, invoice communication to the AT and SAF-T (PT) files: tell us your country and we will confirm your go-live date. Until Skyline Nexus ERP appears on the AT's list of certified programs, a business subject to the certification rule issues its invoices from a certified program or the AT's own invoicing applications and brings them into the ledger with Import Sales, which previews each batch and can revert it. Portuguese payroll runs in local payroll software or through a payroll partner, with the monthly journal posted to the ledger.

Rates, regimes and deadlines in this summary change, and many countries are actively legislating on e-invoicing. This is general information, not tax or legal advice — confirm the current position with the authority named above or with your tax adviser before you rely on it.