Where is telephone country code 00831?

Answer 1

Telephone country codes never begin with zero.

Country code +831, dialed as 00 831 from many places, is an unused country code. There are no valid telephone numbers beginning with +83.

Country code +31, dialed as 008 31 from many places, is the Netherlands.

To avoid confusion, it is best to write an international telephone number in correct international format, beginning with the plus symbol and the correct telephone country code (e.g., +852 or +31), omitting any dialing prefix.

(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.)