The Deutschlandticket is purchased from a transportation company and can be used nationwide within the applicable regulations. 

To allocate the revenues to the regions where users use the Deutschlandticket, we collect zip code information. We assume that you as an user typically use the ticket in the area where you reside, hence the allocation of fares is based on zip code.

The Deutschlandticket was introduced on short notice, and initially, some procedural questions were unresolved. For instance, there was no mechanism for nationwide distribution of ticket revenues. It was agreed to regulate this, in part, through the use of zip codes.