Z06Biker wrote:I thought that with Discover's purchase of Diner's Club, they therefore inherited DC's Mastercard network which meant all Discovers can now be used at any Mastercard-accepted merchant worldswide (read: everywhere)?
No. You can use a US issued Discover Card at foreign locations that take Diner's club; in Japan and China, there are different acceptance marks to look for.
US issued cards are different from Diner's in the rest of the world. They're really mastercards, at least in the US. (I have no idea about foreign acceptance.)
Also, the Discover website is out of date with a list of countries that you can use the card at. I was just in Serbia, Croatia, and Montenegro, and was able to use the card there; none of which are listed at discover.com. (Phone reps knew I could, though.) Acceptance wasn't great, but hotels, chain gas stations, and Europcar all took it. Croatian acceptance seemed highest, but I was only in very,very tourist centered Dubrovnik there, which might have been a factor. It might also be that Discover hooked up with the right bank; I saw several places that had Visa, MC and Diner's acceptance stickers, but not an amex one (and at least one of the places really didn't take amex; I asked.) I had to point to the diner's logo on the back of the card a couple of times.