It interesting that you say that because on our August trip I found paying for everything in both Spain and France so much easier than past trips since everyone from street vendors on up now has contactless tap devices. On past trips, the machines at stores always defaulted to chip and signature with American cards, which annoyed the cashiers who then had to dig out a pen to have us sign and some systems just rejected the cards (we had one stay at a guesthouse in Germany in 2015 where the owner was unable to process the transaction using her point of sale device, but was able to enter the exact same credit card information into her online payment system and have it process). With the contactless payments (e.g. "tap to pay") we were never asked to provide ID or a signature and our card went through almost every single time. The only place we had an issue was the fare vending machines for the Barcelona Metro, which weren't tap to pay and rejected 3 of my 4 cards.
