Originally Posted by tmiw

Initially I was thinking that it was something with how the Schwab debit card's programmed that's preventing DCC from happening but now I'm wondering if my theory about them not bothering for small amounts is correct. I don't want to pull out £100+ to confirm though, especially since I may have a difficult time spending all of it before leaving.

Unless, of course, you did pull out a lot during the previous trip and it still didn't ask. In that case, I have no idea why.