All foreign nationals who hold a temporary work visa a permanent work visa, or an investor's visa and have been in Brazil for longer than 183 days within a 12 month period are required to pay tax on any income received,  Brazilian or overseas.

income tax on revenues received outside of brazil can be adjusted depending on the tax treaty between brazil and that specific country, and depending on how much taxes have been paid on said revenues already.

when in rio de janeiro or brazil under a resident status, all income and assets must be declares to the receita federal, the institution in charge of assessing and collecting taxes.