I usually carry my passport as well (though now I also have a national ID card which I think can take its place within the EU while traveling). But I don't thi

I usually carry my passport as well (though now I also have a national ID card which I think can take its place within the EU while traveling). But I don't think that being able to travel with the thing is a requirement for it to be acceptable as an "additional photo ID" for the kinds of validation we're talking about here. Even if I can't travel with my Skatteverket or residence permit cards, they have been regularly accepted as ID verification for services based outside of Sweden. They've been sufficient when it comes to showing that I do indeed have the relevant Swedish identification documents and reside here. I think once, possibly for E-trade, this was coupled with having to provide a bill sent to my Swedish address. But that shouldn't really be a big issue either for anyone actually residing in another country.