Where is area code 820?

Answer 1

There is no area code +1 820 in North America (USA, Canada, etc.), nor is there a country code +820. Country code +82 is South Korea, but there are no valid numbers that begin with +82 0.

(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, Japan uses 010, Australia uses 0011, and many other countries use different prefixes.)