Core part tax
Under § 10 UStG (German VAT Act), exchanging an old part for a replacement part counts as a separate taxable supply. The value of the old part is assessed at a flat 10 % of the net price of the exchange part purchased, and the standard VAT rate of 19 % is applied to that amount. This amount appears separately on the invoice as core part tax and is independent of the deposit, which is refunded upon return.