When you come to Finland to work, your tax treatment depends on how long you stay and whether you work for a Finnish or a foreign employer.
Personal IDs are issued by the Finnish Digital Agency, and by the Finnish Tax Administration, Finnish missions abroad and the Finnish Immigration Service.
If you are a foreign student or trainee, Finland does not usually impose tax on income you receive from other countries. If you receive income from a Finnish employer, you pay income tax to Finland.
If you live in Finland and receive pension from abroad, the taxation of your pension is usually determined by a tax treaty signed between Finland and the country paying the pension. Always report your pension in a Finnish tax return.
If you receive capital gains on securities from abroad, they are usually taxed only in Finland. Foreign-sourced dividends, on the other hand, are usually taxed in the source country. The tax-at-source you have paid is taken into account in your tax assessment in Finland.