Nobody wants trouble with tax authorities because of insufficient bookkeeping. Thus, it is crucial to use the right software for cash register systems and vending machines. The software should be designed in such a manner that it cannot be reprogrammed and does not use databases that can be modified manually. If this should be the case, however, tax authorities expect evidence for alterations made (programming protocols) which is additional effort for operators. To be on the safe side, only non-manipulative software should be used from the beginning.