The long-awaited Federal Ministry of Finance letter on the retroactive effect of invoice correction and the deduction of input VAT, in the absence of a proper invoice, has now been published. The Federal Ministry of Finance’s letter implements the ECJ case law of 15 September 2016 in the cases of Senatex and Barlis 06, as well as other subsequent rulings. Accordingly, an incorrect invoice, which contains the five core characteristics, can now be corrected retroactively. In the instance of a presumed reverse charge case, showing VAT retroactively is also possible. A retroactive correction of an invoice is also possible in circumstances where the correction is made by cancelling and issuing a new invoice. Input VAT can also be deducted from an incorrect invoice without an invoice correction if the taxable person is able to provide objective proof in other ways. However, according to the Federal Ministry of Finance, showing VAT in an invoice is a key element and cannot be replaced by any other form of evidence. Furthermore, input VAT deduction, without an invoice, remains impossible.