The Solidarity Surcharge Act in its present form was introduced in 1995 to finance the costs of German reunification and still exists today. Since 1998, the tax rate has been 5.5% of income and corporation tax.
The solidarity surcharge (“Soli” for short) is a supplementary tax pursuant to Art. 105 para. 2 in conjunction with Art. 106 para. 1 no. 6 of the Basic Law, the proceeds of which are paid solely to the Federal Government. From 2020, the revenues will amount to approximately €20 billion per year. The Solidarity Pact II, which provides for special federal funds for reconstruction in the East, ends at the end of 2019; from 2020, the federal/state financial relations will be placed on a new legal basis. A "refinancing" of special federal funds is therefore no longer necessary, especially since the income from the solidarity fund exceeds the expenditure for reconstruction in the East by around €70 billion between 1995 and 2019.
There are no indications that the Solidarity Surcharge Act will either be repealed without replacement from 2020 or that the resulting tax burden will be constitutionally integrated into income or corporation tax.
After the Finance Court of Lower Saxony, in its decision of 21 February 2014 (7 K 143/08), had already submitted this question to the Federal Constitutional Court because of doubts about the constitutionality of the “Soli”, this legal question should be pursued further before the Finance Courts with further model proceedings for the legal situation as of 2020.
If you want to become a model plaintiff, please contact the “Bund der Steuerzahler Deutschland e.V.” first.