What should be considered in the case of charge reductions?

In this respect, the tax rate applicable at the time of the transaction is relevant. If the reduction in remuneration is attributable to transactions at different tax rates and/or to non-taxable or tax-exempt transactions, the circumstances of the advance notification period may be used as the basis for the reduction in remuneration for reasons of simplification (margin note 27). Annual bonuses or refunds are to be apportioned in proportion to the turnover attributable to the respective period or to be divided equally over the calendar year (margin note 32). Appropriate statements of account must be issued.

In the case of deposit amounts, the adjustment can be made from 01.07. up to and including 30.09.2020 at 19% or 7% and from 01.10. up to 31.12.2020 at 16% or 5% (margin note 31).

In addition, deposit money between traders entitled to deduct input tax can be settled at 16% throughout the 2nd half of 2020, if both the VAT at the supplying trader and the input tax at the service recipient are adjusted at this tax rate and from 01.01.2021 this settlement method for deposit money is applied at 19%

Die genannten Rz. beziehen sich auf das BMF-Schreiben vom 30.06.2020 a.a.O.

BMF-Schreiben vom 30.06.2020 zur befristeten Absenkung des allgemeinen und ermäßigten Umsatzsteuersatzes zum 1. Juli 2020, BStBl I 2020, 584

BMF-Schreiben vom 02.07.2020 zur befristeten Anwendung des ermäßigten Umsatzsteuersatzes für Restaurations- und Verpflegungsdienstleistungen zum 1. Juli 2020, BStBl I 2020, 610

Merkblatt zur Umsatzbesteuerung in der Bauwirtschaft, BStBl I 2009, 1292