Portugal's First Global Minimum Tax Returns Fall Due on 30 September, Three Months Later Than Planned

Portugal's tax calendar for September carries an entry that has never appeared on it before. On 30 September, the country's first returns under the Regime do Imposto Minimo Global fall due at the Autoridade Tributaria: Modelo 63, the GloBE information return, for the 2024 tax year, and Modelo 62, the registration declaration, for 2025.

This is the Portuguese end of the OECD's Pillar Two agreement, transposed by Lei 41/2024 of 8 November. It sets a floor of 15 percent on the effective tax rate paid by multinational groups and by large purely domestic groups whose consolidated annual revenue reaches 750 million euros. Where a group's effective rate in a jurisdiction falls below that floor, a top-up charge closes the gap.

Why the date moved

The original deadline was 30 June 2026. Despacho 76/2026-XXV, issued on 3 June, pushed it to 30 September for groups whose financial year ended between 31 December 2024 and 31 March 2025, and did so without additional charges or penalties. Lei 26/2026, published the same day, clarified when a designated local entity is relieved of filing Modelo 62 because the ultimate parent files a centralised information return in its own jurisdiction.

The forms themselves arrived in stages. Portaria 290/2025/1 of 2 September approved the registration declaration, Modelo 62. The information return, Modelo 63, was approved to satisfy the reporting obligation in article 45(1)(b) of the regime, and the Tax Authority's submission service for the 2024 year is now open.

Who this actually reaches

The 750 million euro threshold means this is not a small-business obligation. It captures the Portuguese subsidiaries and branches of large foreign groups, and the handful of Portuguese groups big enough to clear the bar. For most of them the practical work is not the tax owed, which in a country with a 20 percent headline corporate rate is frequently nil, but the data collection: the regime requires jurisdiction-by-jurisdiction effective rate calculations built from accounting figures that were never assembled for this purpose.

That work is why the deadline moved. The filing is a compliance exercise before it is a revenue exercise, and the three-month extension was an acknowledgement that the first pass through it is the hardest.

The rest of the September calendar

Around it sit the ordinary monthly obligations, collected by the Ordem dos Contabilistas Certificados. The SAF-T invoicing file for August is due on 7 September and the monthly remuneration return on 10 September. The 15th brings Modelo 11 from notaries, the Intrastat survey, and the tobacco declaration setting each operator's quantitative ceiling for cigarettes, cigarillos and fine-cut tobacco. The 21st carries the periodic VAT return for monthly filers covering June and July, and for quarterly filers the second quarter. VAT payment and the Social Security contribution on August pay both fall on 25 September.

What this means for expats

• If you work for a large multinational here: your employer's Portuguese entity is probably inside the regime, and the 30 September date is a group filing rather than anything that touches your own return.
• If you run a company: the ordinary September dates above are the ones that bind you. Registry delays are running long, so leave slack around anything that needs a commercial certificate.
• If you disagree with an assessment: our guide to contesting a tax assessment sets out the reclamacao graciosa, the hierarchical appeal and CAAD arbitration.
• Context on who pays: foreign-owned firms are 3 percent of Portuguese companies and 46 percent of exports, which is roughly the population the global minimum tax is aimed at.
• Personal deadlines have passed: IRS payment closed on 31 August, with the instalment request open until 15 September.