Short Answer
Germany utilizes a regulatory mechanism called Progressionsvorbehalt to factor your global real estate earnings into your local tax assessment calculation. While the state does not directly seize your foreign rental income, adding those profits to your overall profile pushes your German salary into a significantly higher tax bracket.
What Most Expats Don't Realize
You owned a rental apartment in your home country and assumed the revenue was completely irrelevant to the local finance office because it was already taxed locally. You filed your annual German declaration without mentioning the overseas property and skipped the mandatory global reporting attachments. The tax office audited your profile, added the foreign real estate profit to your total valuation, and retroactively raised your domestic tax rate, resulting in an unexpected cash loss of 1,200 € in back-taxes.
What To Do
- Open the official annual tax filing platform and navigate to the dedicated attachment labeled "Anlage AUS."
- Calculate your exact foreign net profit by subtracting your verified overseas property maintenance expenses from your gross rental income.
- "Ich deklariere meine ausländischen Mieteinnahmen unter Progressionsvorbehalt." (I am declaring my foreign rental income under the progression clause.) — write this statement inside the comment section of your electronic return.
The Truth
German tax logic dictates that knowing you possess foreign money justifies charging you a higher percentage on the income you generate domestically.