> I'm not even sure if I need a passport to cross the border to France for a day trip. You should always bring EU-approved ID when crossing EU borders (even in

> I'm not even sure if I need a passport to cross the border to France for a day trip. You should always bring EU-approved ID when crossing EU borders (even internal). There can be checks for a number of reasons. For example, many moons ago high in the Alps, at the border between France and Italy, I witnessed two people on a French motorbike being turned back by the Italian customs for not having ID. Worst case scenario for you would be to not be let back in.