Portuguese IRS 2026 (2025 income): preparation, timing and international risk exposure
The annual IRS filing season is approaching — a moment that deserves particular attention for individuals and families with more complex wealth profiles.
The Portuguese tax return relating to 2025 income must be submitted between 1 April and 30 June 2026. In practice, however, preparation should begin well before that.
By 2 March 2026, invoices must be validated in the e-Fatura system, household details confirmed, and relevant information updated. The tax assessment is typically issued by the end of July, with any additional tax due payable by the end of August.
Individuals who were tax residents in Portugal in 2025—for the full year or only part of it—are generally required to declare their worldwide income and gains for the period of residence.
Those who were not tax residents in Portugal in 2025 are required to declare only Portuguese-source income subject to IRS, many of which may already have been subject to final withholding tax. Even so, the specific circumstances often require closer analysis where more than one jurisdiction is involved.
Where risk typically arises in practice
The most sensitive issues tend to arise where international elements or more complex wealth structures are involved. Over the past few years, what we have seen most often are not technical errors in completing the return but situations such as
foreign investment income classified in Portugal differently from its treatment in the country of origin;
capital gains realised through corporate vehicles treated as direct personal income;
changes of tax residence during the year without proper analysis of the transitional period;
crypto-assets reported without alignment with the actual transaction history;
wealth structures spanning multiple jurisdictions with inconsistent tax reporting between countries.
In many cases, these situations have no immediate consequences. Issues tend to surface later, following international information exchange, requests for clarification, or post-filing reviews.
We are often asked to step in at precisely that stage: reviewing already submitted returns, responding to tax authority enquiries, and coordinating the tax treatment of income and gains with lawyers, banks, and accountants in other jurisdictions.
A more transparent and demanding environment
The tax landscape has become structurally more demanding. The annual tax return is no longer an isolated compliance exercise; in many cases, it forms part of an increasingly integrated international reporting framework.
Today, this includes, among other elements:
automatic exchange of banking information between jurisdictions;
international reporting of financial accounts and structures;
increased scrutiny of digital assets;
active verification of declared tax residence;
a growing number of corrections and tax disputes involving international IRS matters.
For wealth profiles with international exposure and mobility, seemingly minor inconsistencies can become relevant years later.
What makes the difference
For individuals with higher levels of income or international exposure, preparation should not begin in April. It should begin with a structured review of the 2025 tax position, including:
where each individual was effectively tax resident;
where income and gains were generated and taxed;
how financial flows were structured;
which tax regimes were applied (including special regimes such as the Non-Habitual Resident — NHR — and IFICI regimes);
whether economic reality aligns with tax reporting across jurisdictions.
In practice, the difference between simply filing a return and establishing a robust tax position lies in this prior review. The cost of anticipating and structuring the return correctly is typically negligible when compared with the potential impact of an audit, reassessment, or tax dispute.