German taxes for Interactive Brokers, Tastytrade & DEGIRO

Yes. A German bank withholds the tax directly, which settles it. Interactive Brokers, Tastytrade and DEGIRO do not — and because no German tax was withheld, you are required to declare it (§ 32d Abs. 3 EStG). That is an obligation, not an option. Only dividends of German shares are usually already settled by German withholding – see Dividends of German shares.

Because you have no German Steuerbescheinigung. A German broker runs FIFO, currency conversion, withholding tax and loss offsetting for you and reports finished figures. A US broker gives you raw data — the classification is up to you.

Interactive Brokers, Tastytrade and DEGIRO (beta). Plus every introducing broker on the IBKR platform — LYNX and CapTrader among them: their Activity Statement comes out of the same IBKR system, so you simply pick Interactive Brokers.

Capital income on Anlage KAP, fund and ETF income on Anlage KAP-INV, private disposals such as gains on non-interest-bearing foreign-currency balances on Anlage SO (for interest-bearing balances see currency gains). With a foreign broker, Anlage KAP mainly uses line 19 (all foreign capital income), lines 20 and 23 (share gains and losses contained in it), line 22 (other losses) and line 41 (creditable withholding tax); for 2021 to 2024, lines 21 and 24 are added for options. The detailed mapping is under Anlage KAP, KAP-INV & SO.

At most the rate the US is allowed to keep under the double-taxation treaty: 15 % on dividends — and at most 25 % per item of income (§ 32d Abs. 5 EStG). With a valid W-8BEN the US withholds exactly those 15 %, and for dividends from shares all of it is creditable.

For private investors, on Anlage KAP — not Anlage SO. Up to and including 2024, writer premiums and forward transactions had their own lines there; since the 2025 form they are part of the total capital income, and losses also go on the line for losses other than share losses.

Yes. Your data never leaves your computer. Everything is calculated in your own browser, so there is no upload and no copy on a server. We have no technical way to see your transactions. Once you close the page, the data is gone.

capi.tax is currently free. It is a private project — feedback is very welcome. There is no subscription, no payment details and no account.

No. capi.tax prepares your data and does not constitute tax advice. It reads your broker export, converts the amounts to euro, applies the rules of German tax law and gives you a structured summary for your tax return. The figures are a starting point, not a final verdict. For your personal situation, please review the result and talk to a tax advisor (Steuerberater).