Also if you think well i will just fly to X country for a few days every week or whatever and then declare that i did my work there and during my stay in Portugal i just bum around at the beach... that is not going to work either. Double taxation treaties will shift the taxation onto Portugal and there are even provisions where those treaties do not exist and you are not getting taxed at least the PT amount that PT can/will just tax you. Forget about PT with active income.