The decisive factor is the execution of the transaction (Section 27 (1) sentence 1 UStG). Sales that are executed after 30 June 2020 are subject to the new tax rates. The contractual agreement, invoicing or receipt of payment is irrelevant. (marginal no. 4). For sales to other entrepreneurs between 01.07. and 31.07.2020, the tax rates of 19% or 7% can still be shown for reasons of simplification. The entrepreneur must pay the VAT in the amount shown and an input tax deduction is permitted in this amount (margin note 46). The non-objection rule also applies to advance and down-payment invoices if the underlying service is provided in July 2020.
The aforementioned paragraphs refer to the BMF letter of 30 June 2020, loc. cit.