yfan wrote:In Asia, acceptance is very high, especially in China and Japan. Due to an agreement between Discover and China Pay, Discover is accepted anywhere China Pay is, and in China, that makes Discover the most accepted network, outstripping even Visa and Mastercard. There is a similar agreement in place with JCB, Japan's largest payment network.
Tried on UnionPay network this year without problem, while only a few merchants could take Visa or MasterCard. Present the card and the cashier sometimes won't look into the card and transaction goes through; otherwise they may tell they don't recognize the card, therefore have to explain the card runs on UnionPay. Can only run on UnionPay network within mainland excluding Hong Kong - Discover said they should work on Diners Club network there, but never had chance to try.
One problem would be if Discover equips chip technology, it would be EMV, which is different from China's PBOC standard on its national bank cards. This might cause some problem or not, as now China no longer allows fallback transaction on Chip card + Chip terminal.
If OP is going to Europe, let the card run on Diners Club network, but it is better to also bring the Visa card, regardless of chipped or not. Should be OK at most manned locations, but always remember to have some cash.
Always report international travel plans to Discover, so the card won't be blocked for suspected fraud activity.