This I knew. But I was under the impression that Visa was more accepted overseas than MC, not less. Maybe the situation is different in Brazil or other countries I haven't visited lately (last time I was in Brazil I was 6 years old), but I don't think I've been in a situation in recent years where I could use an international credit or ATM card but not use Visa. My recent experiences come from China, Hong Kong, Israel, the UK, Holland, Spain, Guatemala and Belize. The only time I've opted to pull out a MC instead was the Israel rental car thing, where Hertz didn't make me pay CDW if I used MC instead of Visa. In Guatemala, I'm pretty sure Visa was the only card accepted at some stores I visited.