Yet for those with income or assets abroad – whether from pensions, investments, property, or digital assets – the process is far from straightforward. Misreporting or omitting key information can result in unexpected tax exposure, penalties, and even long-term scrutiny.

Portugal’s personal income tax regime requires residents to declare their worldwide income. However, the way foreign income is taxed – or exempt – depends not only on domestic law but also on the specific provisions of double tax treaties. Understanding the interaction between foreign rules and Portuguese tax treatment is critical. For instance, some countries tax income on a gross basis with no deductions, while others apply withholding taxes that may or may not be creditable in Portugal. Submitting accurate figures often demands careful reconciliation of foreign documents and reporting standards.

This year, the stakes are even higher with the introduction of new mandatory reporting requirements. For the first time, crypto assets must be declared in the Portuguese tax return. Taxpayers who held crypto on 31 December 2024 are now required to report their holdings, even if no sale or income has occurred. This marks a significant shift from previous years, where crypto was largely unregulated for tax purposes.

Equally important is the obligation to report foreign accounts and assets held in jurisdictions classified as tax havens. Portugal maintains a strict and broad list of so-called “offshore jurisdictions,” which includes not only the usual suspects – like the British Virgin Islands, Guernsey, Jersey, and the Cayman Islands – but also some jurisdictions not typically seen as tax havens elsewhere, such as the Isle of Man, Gibraltar, and even Hong Kong. Dutch individuals may be surprised to learn that the Dutch Caribbean islands of Aruba, Curaçao and Saint Maarten also feature on the list. Holding assets in these jurisdictions – even dormant accounts or non-income-generating structures – triggers specific reporting obligations and may lead to higher tax rates or restrictions on tax deductions.

Portuguese authorities are increasingly focused on international transparency and the automatic exchange of information. Failing to report these assets properly can raise red flags and lead to audits or penalties.


In this evolving landscape, accurate and complete reporting is essential. While software tools and automated platforms may help with simple returns, they rarely capture the complexity of international situations. Seeking professional advice – especially where foreign income, trusts, crypto, or tax havens are involved – can help avoid costly mistakes and ensure full compliance.

Filing a return is not just about meeting a deadline. It’s a chance to take stock of your affairs, identify planning opportunities, and reduce the risk of future issues with the tax authorities.

Mário Patrício, Senior Manager at Forvis Mazars in Portugal (mpatricio@mazars.pt)