u/snic09

My German citizenship is newly minted, and for the first time I'll be travelling to the Schengen area as a dual US/German citizen. I've read all the Talmudic discussions on which passport to show the airline, which passport to leave the country with, and which passport to enter the country with. My question is different. Assuming I live in the US, not in Europe, and that I enter Europe with my German passport or ID card, which passport/ID should I use for non-border purposes, such as renting a car or checking in to a hotel? Is there any reason why one might be better than the other?

(I only have a US driver license - but rental companies still want to see your passport or national ID.)