The deadline for filing personal income tax details is approaching, and residents of Portugal who work for a foreign company based overseas must also submit their earnings to the Portuguese tax authorities.

That is, all taxpayers who pay taxes in Portugal are required to declare not only income earned nationally but also income earned in other countries.

Generally, this declaration is made using Annex J of the Model 3 personal income tax return, in accordance with guidelines issued by the Tax and Customs Authority (AT).

When filling out the tax form, people must use Annex J of the Model 3, in accordance with guidelines provided by the Tax and Customs Authority (AT). The annex is meant to be used to report income and taxes paid abroad.

The measure is mandatory, as the authorities obligate taxpayers to inform them of taxes paid abroad, even if the taxpayer believes there will be no charges of income made abroad, in Portugal.