Tax
The Solidaritätszuschlag (solidarity surcharge) is a 5.5 per cent surcharge on the flat capital-gains tax, not on the income; with the 25 per cent rate it yields an effective burden of roughly 26.375 per cent.
The Solidaritätszuschlag, or Soli for short, is 5.5 per cent. On investment income it is charged not on the income itself but on the Abgeltungsteuer (flat capital-gains tax) already calculated.
For income tax, the Soli has no longer applied to most taxpayers since 2021. On investment income, however, it remains in place and is withheld by the broker together with the flat capital-gains tax.
In arithmetic terms, 25 per cent flat tax plus 5.5 per cent Soli on top produce an effective burden of roughly 26.375 per cent. If church tax also applies, the effective rate rises further.
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