In its letter dated 13 February 2024, the Federal Ministry of Finance (BMF) comments on the topic of input VAT apportionment in the case of mixed use of procured supplies. This topic is of crucial practical relevance and, at the same time, is often the subject of controversial discussions, especially in the course of VAT audits carried out by the tax authorities. In particular, the letter comments on the relationship between a total turnover-based allocation key and other apportionment methods. The BMF also explains how the total turnover-based allocation key is to be calculated. Essentially, these are clarifications, rather than groundbreaking innovations.