You live Portugal and receive pension from Finland
If you live in Portugal and receive pension from Finlad, you must pay tax on the pension to Finland.
You have to pay tax to Finland and Portugal
If you are paying tax on your pension to both countries, contact the Portuguese tax authorities to ask for double taxation to be eliminated for the part of your income consisting of Finnish-sourced pensions. Taxes you have paid to Portugal on your Finnish-sourced pensions do not affect your tax assessment in Finland.
You own an apartment in a housing company in Finland
Starting 2019, individuals living in Portugal must pay tax to Finland on the pension income they receive from sources in Finland
Finland has ended the tax treaty between Finland and Portugal signed in 1970. The treaty ceased to be applied on 31 December 2018. A new treaty signed in 2016 was accepted in Finland, but it was not accepted in Portugal in time. Therefore, starting 1 January 2019, Finland and Portugal have not had a tax treaty.
No tax treaty means that Finland’s taxing rights are not restricted, and you must therefore pay tax to Finland on pensions you receive from Finnish sources.
For more information about pension income, see “Taxation of pensions in cross-border circumstances” – Eläketulojen verotus kansainvälisissä tilanteissa (available in Finnish and Swedish, link to Finnish), onwards from section 6.2. “Pension received from a Finnish source – Suomesta saatu eläke”.