What area codes do you put in when texting from Mexico to USA?

Answer 1

The telephone country code for the USA is +1.

To send a text to a US mobile phone (cell phone), the number is +1 (three-digit area code) (7-digit subscriber number). The US uses the same geographic area codes for mobile numbers as for landlines; there is no distinction in the numbering.

(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.)