Anyone who lends out Bitcoin or other crypto assets in return for a fee pays their personal income tax rate on it, not the flat withholding tax, according to the only ruling by a German tax court so far. The Cologne Tax Court decided this on September 10, 2025, under case number 3 K 194/23. The taxpayer has appealed on a point of law, the proceedings are with the Federal Fiscal Court, and until a decision comes down there the question stays open.

For you this has two very practical consequences. The income belongs on a different line of your tax return than many investors assume. And if your tax office assesses it the way the Cologne Tax Court has laid out, you can lodge an objection and have the proceedings suspended until the Federal…