Don't even think about using your cell phone in a bank either! I guess they think that you're trying to arrange a bank heist if you talk on the phone. Even though I'm sure that bank robbers have more sophisticated technology. When you finally got to a teller you'd have to stand at the window and all transactions seemed to take forever. Banks were open longer, often until 6pm and on Saturdays as well though.
One tip to remember is that speaking Spanish will help you greatly. You'll be treated differently than if you speak English all the time,it'll help you assimilate to the culture, and you'll be able to communicate easier. If you're looking to learn Spanish, check out Fluenz Spanish, Rosetta Stone, and Synergy Spanish.
Things are a bit different in Korea. Online banking is common which means that most banks close around 4pm. There are a few that are open 24 hours, like those at the airport. You can also do a lot through the ATM, like pay your utility bills (No rounding up either like they do in Peru. By skimming a couple cents off the whole population Peruvian utility companies have found an extra way to make money.). No guns either and the security guards are nice and usually wear white gloves, bow, and greet you as you enter the bank and upon leaving as well.
As for cell phone? Koreans are addicted to them. Like Peru you might have to wait a while, but there are comfy chairs and you can use your cell phones while waiting. When your number finally pops up on the screen you get to sit down in front of a teller (who incidentally usually stands up, bows, and greets you as you come to their window).
I do miss the longer hours that Peruvian banks are open and the fact that they're open on Saturdays, but other than that, Korean banks are much better.
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