An invoice will be refused on the grounds that it was a private purchase. In addition, Navigon does not always offline. From time to time, the program asks for authentication through the Amazon App Store. According to Amazon, I have indeed acquired the right to use the software offline but not to use the license to use offline. Original Amazon: "The offine use of the software is not related to the navigation, but on the digital rights management". As it would be possible to use the one or the other.
