Hello, when online declare the tax for myself, there is a "Kosten für auswärtigen Wochenaufenthalt", what does this means? should I input all the business trip cost there? thanks
No, That is if you are registered as a Wochenaufenthalter.
"Wochenaufenthalter": You are renting an apartment or room near your workplace where you stay during the week, but you actually live somewhere else. The additional costs of that apartment or room can be claimed as an expense.